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Cheng R, Li L, Zhen S, Liu H, Wu Z, Wang Y, Wang Z. Rapid Detection of Staphylococcus aureus in Milk and Pork via Immunomagnetic Separation and Recombinase Polymerase Amplification. Microbiol Spectr 2023; 11:e0224922. [PMID: 36847574 PMCID: PMC10101137 DOI: 10.1128/spectrum.02249-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 02/04/2023] [Indexed: 03/01/2023] Open
Abstract
Separation processes using immunomagnetic beads (IMBs) are advantageous for the rapid detection of Staphylococcus aureus (S. aureus). Herein, a novel method, based on immunomagnetic separation using IMBs and recombinase polymerase amplification (RPA), was employed to detect S. aureus strains in milk and pork. IMBs were formed by the carbon diimide method using rabbit anti-S. aureus polyclonal antibodies and superparamagnetic carboxyl-Fe3O4 MBs. The average capture efficiency for 2.5 to 2.5 × 105 (CFU)/mL gradient dilution of S. aureus with 6 mg of IMBs within 60 min were a range of 62.74 to 92.75%. The detection sensitivity of the IMBs-RPA method in artificially contaminated samples was 2.5 × 101 CFU/mL. The entire detection process was completed within 2.5 h, including bacteria capture, DNA extraction, amplification, and electrophoresis. Among 20 actual samples, one case of raw milk sample and two cases of pork samples were tested positive using the established IMBs-RPA method, which were verified by the standard S. aureus inspection procedure. Therefore, the novel method shows potential for food safety supervision owing to its short detection time, higher sensitivity, and high specificity. IMPORTANCE Our study established IMBs-RPA method, which simplified the steps of bacteria separation, shortened the detection time, and realized the convenient detection of S. aureus in milk and pork samples. IMBs-RPA method was also suitable for the detection of other pathogens, providing a new method for food safety monitoring and a favorable basis for rapid and early diagnosis of diseases.
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Affiliation(s)
- Runan Cheng
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Lei Li
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Sihui Zhen
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Honglei Liu
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Zhouhui Wu
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Yu Wang
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
| | - Zhen Wang
- Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Animal Science and Technology College, Beijing University of Agriculture, Beijing, China
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Rapid Analysis for Staphylococcus aureus via Microchip Capillary Electrophoresis. SENSORS 2021; 21:s21041334. [PMID: 33668587 PMCID: PMC7917630 DOI: 10.3390/s21041334] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/05/2021] [Accepted: 02/09/2021] [Indexed: 11/17/2022]
Abstract
Staphylococcus aureus (S. aureus) is one of the most common pathogens for nosocomial and community infections, which is closely related to the occurrence of pyogenic and toxic diseases in human beings. In the current study, a lab-built microchip capillary electrophoresis (microchip CE) system was employed for the rapid determination of S. aureus, while a simple-to-use space domain internal standard (SDIS) method was carried out for the reliable quantitative analysis. The precision, accuracy, and reliability of SDIS were investigated in detail. Noted that these properties could be elevated in SDIS compared with traditional IS method. Remarkably, the PCR products of S. aureusnuc gene could be identified and quantitated within 80 s. The theoretical detection limit could achieve a value of 0.066 ng/μL, determined by the using SDIS method. The current work may provide a promising detection strategy for the high-speed and highly efficient analysis of pathogens in the fields of food safety and clinical diagnosis.
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3
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Dai G, Li Z, Luo F, Lu Y, Chu Z, Zhang J, Zhang F, Wang Q, He P. Simultaneous electrochemical determination of nuc and mecA genes for identification of methicillin-resistant Staphylococcus aureus using N-doped porous carbon and DNA-modified MOF. Mikrochim Acta 2021; 188:39. [PMID: 33433669 DOI: 10.1007/s00604-020-04698-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 12/31/2020] [Indexed: 12/01/2022]
Abstract
The detection of Staphylococcus aureus specific gene in combination with the mecA gene is vitally important for accurate identification of methicillin-resistant Staphylococcus aureus (MRSA). A homogeneous electrochemical DNA sensor was fabricated for simultaneous detection of mecA and nuc gene in MRSA. Metal-organic framework (type UiO-66-NH2) was applied as nanocarrier. Two electroactive dyes, methylene blue (MB) and epirubicin (EP), were encapsulated in UiO-66-NH2, respectively, and were locked by the hybrid double-stranded DNA. Based on the target-response electroactive dye release strategy, once target DNA exists, it completely hybridizes with displacement DNA (DEP and DMB). So DEP and DMB is displaced from the MOF surface, causing the release of electroactive dyes. Co-Zn bimetallic zeolitic imidazolate framework-derived N-doped porous carbon serves for electrode modification to improve electrocatalytic performance and sensitivity. The differential pulse voltammetry peak currents of MB and EP were accurately detected at - 0.14 V and - 0.53 V versus the Ag/AgCl reference electrode, respectively. Under the optimal conditions, the detection limits of mecA gene and nuc gene were 3.7 fM and 1.6 fM, respectively. Combining the effective application of MOFs and the homogeneous detection strategy, the sensor exhibited satisfactory performance for MRSA identification in real samples. The recovery was 92.6-103%, and the relative standard deviation was less than 5%. Besides, MRSA and SA can also be distinguished. This sensor has great potential in practical applications.
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Affiliation(s)
- Ge Dai
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China
| | - Zhi Li
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China
| | - Feifei Luo
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China
| | - Yuqi Lu
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China
| | - Zhaohui Chu
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China
| | - Jingwen Zhang
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China
| | - Fan Zhang
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China.
| | - Qingjiang Wang
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China.
| | - Pingang He
- School of Chemistry and Molecular Engineering, East China Normal University, 500 Dongchuan Road, Shanghai, 200241, People's Republic of China
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Santos GAC, Dropa M, Rocha SM, Peternella FAS, Razzolini MTP. Staphylococcus aureus and methicillin-resistant Staphylococcus aureus (MRSA) in drinking water fountains in urban parks. JOURNAL OF WATER AND HEALTH 2020; 18:654-664. [PMID: 33095190 DOI: 10.2166/wh.2020.042] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The presence of Staphylococcus aureus in drinking water is a concern because of its potential to cause human infection and also because of its multiple antimicrobial resistance. This study evaluated the water quality of drinking water fountains and mist makers in four municipal parks of São Paulo for 13 months. Although all samples met bacteriological water quality criteria according to Brazilian regulations, the absence of residual chlorine (<0.1 mg/L) was observed. These data were significantly correlated with the frequency of S. aureus that was found in 25.2% of the samples. The mecA gene was detected in 36.7% of the isolates demonstrating its potential for resistance to several antimicrobials. Furthermore, 27.3% isolates carrying the mecA gene had methicillin-resistant Staphylococcus aureus (MRSA) phenotypic potential. The presence of S. aureus with characteristics of microbial resistance in water for human consumption is an unprecedented finding. Hence, conducting surveillance for opportunistic bacteria, such as staphylococci in drinking water, is reasonable to take control measures and to protect human health, especially in public places with high attendance.
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Affiliation(s)
- Geyse A C Santos
- School of Public Health, University of São Paulo, Av. Dr Arnaldo, 715 - 1o andar 01246-904, São Paulo, Brazil E-mail: ; NARA - Center for Research in Environmental Risk Assessment, Department of Environmental Health, School of Public Health of University of São Paulo, Av. Dr Arnaldo, 715 - 1o andar 01246-904, São Paulo, Brazil
| | - Milena Dropa
- School of Public Health, University of São Paulo, Av. Dr Arnaldo, 715 - 1o andar 01246-904, São Paulo, Brazil E-mail:
| | - Solange M Rocha
- School of Public Health, University of São Paulo, Av. Dr Arnaldo, 715 - 1o andar 01246-904, São Paulo, Brazil E-mail:
| | - Francisca A S Peternella
- School of Public Health, University of São Paulo, Av. Dr Arnaldo, 715 - 1o andar 01246-904, São Paulo, Brazil E-mail:
| | - Maria Tereza Pepe Razzolini
- School of Public Health, University of São Paulo, Av. Dr Arnaldo, 715 - 1o andar 01246-904, São Paulo, Brazil E-mail: ; NARA - Center for Research in Environmental Risk Assessment, Department of Environmental Health, School of Public Health of University of São Paulo, Av. Dr Arnaldo, 715 - 1o andar 01246-904, São Paulo, Brazil
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Zieliński W, Korzeniewska E, Harnisz M, Hubeny J, Buta M, Rolbiecki D. The prevalence of drug-resistant and virulent Staphylococcus spp. in a municipal wastewater treatment plant and their spread in the environment. ENVIRONMENT INTERNATIONAL 2020; 143:105914. [PMID: 32615351 DOI: 10.1016/j.envint.2020.105914] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 05/06/2023]
Abstract
Drug-resistant and pathogenic Staphylococcus spp. strains can reach surface waters and air with wastewater evacuated to the environment. These strains increase the environmental pool of genetic determinants conferring antibiotic resistance and virulence, and constitute a health risk for the employees of wastewater treatment plants (WWTP) who come into daily contact with bioaerosols. The aim of this study was to identify the genetic determinants of drug resistance and virulence in Staphylococcus spp. strains isolated from untreated (UWW) and treated wastewater (TWW), an activated sludge (AS) bioreactor, river water collected upstream and downstream from the wastewater discharge point (URW and DRW), and WWTP employees. All isolates were analysed for the presence of the rpoB gene, and were subjected to clonal analysis by ERIC fingerprinting. As a result, 249 of the 455 analysed isolates were selected for PCR. The presence of the gene encoding nuclease activity in S. aureus (nuc), the methicillin resistance gene (mecA), vancomycin resistance gene (vanA), antiseptic resistance gene (qacA/B) and virulence genes (sasX, pvl, tst1, hla, sec) was determined. The prevalence of nuc, mecA, vanA and qacA/B genes in wastewater and river water was determined by quantitative PCR (qPCR). In the group of strains isolated from wastewater and water samples, 63% were identified as S. aureus, and 20% of the strains carried the vanA gene. The hla virulence gene was present in 80% of the isolates, and the pvl gene was detected in 27% of the isolates. In the group of strains isolated from the employees, 82% were identified as S. aureus, and the presence of vanA and mecA genes was confirmed in 14% and 16% of the isolates, respectively. The most prevalent virulence gene was hla (74%), whereas pvl was observed in 43% of the isolates. The quantitative analysis revealed the highest concentrations of the studied genes in UWW samples, at 2.56x104 gene copies/ml for nuc, 1.18x103 gene copies /ml for mecA, 8.28x105 gene copies /ml for vanA and 3.83x105 gene copies /ml for qacA/B. Some of analysed genes were identified in the isolates from both URW and DRW samples, as well as in genomic DNA of these samples. These results indicate that wastewater is not effectively treated in the analysed WWTP, which could contribute to the dissemination of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) to the environment. An analysis of the genetic relatedness of selected isolates revealed clusters of strains originating from UWW samples, AS samples and the employees. These observations suggest that ARGs and ARB are transmitted by wastewater bioaerosols to the upper respiratory tract mucosa of the plant's employees, thus increasing their exposure to infectious factors.
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Affiliation(s)
- Wiktor Zieliński
- Department of Engineering of Water Protection and Environmental Microbiology, The Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1 Str., 10-719 Olsztyn, Poland
| | - Ewa Korzeniewska
- Department of Engineering of Water Protection and Environmental Microbiology, The Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1 Str., 10-719 Olsztyn, Poland.
| | - Monika Harnisz
- Department of Engineering of Water Protection and Environmental Microbiology, The Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1 Str., 10-719 Olsztyn, Poland
| | - Jakub Hubeny
- Department of Engineering of Water Protection and Environmental Microbiology, The Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1 Str., 10-719 Olsztyn, Poland
| | - Martyna Buta
- Department of Engineering of Water Protection and Environmental Microbiology, The Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1 Str., 10-719 Olsztyn, Poland
| | - Damian Rolbiecki
- Department of Engineering of Water Protection and Environmental Microbiology, The Faculty of Geoengineering, University of Warmia and Mazury in Olsztyn, Prawocheńskiego 1 Str., 10-719 Olsztyn, Poland
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McIver CJ, De Silva RND, Er N, Pratama R, Mukerjee C, Stevens R, Taylor PC. A simple and expedient PCR format for rapid molecular screening of methicillin-resistant Staphylococcus aureus in Amies gel swabs. Pathology 2020; 52:466-472. [PMID: 32284213 DOI: 10.1016/j.pathol.2020.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 01/26/2020] [Accepted: 02/04/2020] [Indexed: 11/16/2022]
Abstract
Screening patients for carriage of methicillin-resistant Staphylococcus aureus (MRSA) is commonly undertaken in hospital laboratories using phenotypic methods. This work is labour-intensive, costly and may take several days to complete. We report on the validation of a novel rapid screening approach for direct testing of Amies gel swabs for MRSA. The method is based on two quantitative real time-PCR (qRT-PCR) assays for the detection of the nuc and mecA genes of MRSA. Based on SYBR Green technology, the assays use significantly less reagents than conventional qRT-PCR methods and are applied to testing templates derived directly from aqueous suspensions of swabs. Notwithstanding the occurrence of false-positives due to non-specific fluorescence generated by the SYBR Green dye, the novel assays showed a high negative predictive value enabling earlier reporting of negative findings and selection of swabs for confirmatory phenotypic testing for MRSA. In a blinded trial of 461 swabs, of which 34 (7.4%) were previously shown to be culture-positive for MRSA, the novel assays selected 121 (26.2%) swabs (inclusive of the known MRSA-positive swabs) for phenotypic testing. This enabled early reporting of negative findings for 340 (73.8%) of the 461 swabs tested. Application of this method has implications for screening strategies for large laboratories whilst achieving cost benefits.
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Affiliation(s)
- Christopher J McIver
- Department of Microbiology (NSW HP), St George Hospital, Sydney, NSW, Australia; School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia.
| | | | - Noel Er
- Department of Microbiology (NSW HP), St George Hospital, Sydney, NSW, Australia
| | - Ryanbi Pratama
- Department of Microbiology (NSW HP), St George Hospital, Sydney, NSW, Australia
| | - Chinmoy Mukerjee
- Department of Microbiology (NSW HP), St George Hospital, Sydney, NSW, Australia
| | - Robert Stevens
- Department of Microbiology (NSW HP), St George Hospital, Sydney, NSW, Australia; School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Peter C Taylor
- Department of Microbiology (NSW HP), St George Hospital, Sydney, NSW, Australia; School of Medical Sciences, University of New South Wales, Sydney, NSW, Australia
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7
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Tian X, Feng J, Wang Y. Direct loop-mediated isothermal amplification assay for on-site detection of Staphylococcus aureus. FEMS Microbiol Lett 2019; 365:4966978. [PMID: 29648586 PMCID: PMC5967525 DOI: 10.1093/femsle/fny092] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2018] [Accepted: 04/08/2018] [Indexed: 01/13/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is a major human pathogen that may produce a variety of toxins and cause staphylococcal food poisoning. In the present study, a direct loop-mediated isothermal amplification (LAMP) assay was developed and validated to detect S. aureus in food samples. Without prior cultural enrichment and DNA extraction steps, bacterial DNA was released by heating at 100°C for 5 min and directly subjected to LAMP assay. Using a set of LAMP primers recognizing six distinct regions of nuc gene, the developed direct LAMP assay was highly specific, and the analytical sensitivity was determined to be 7.6 × 102 CFU/mL. Moreover, with the pre-mixed LAMP reagents stored at –20°C, the entire assay should be finished within 40 min. These features greatly simplified the operating procedure and made the direct LAMP a powerful tool for rapid and on-site detection of S. aureus in food samples.
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Affiliation(s)
- Xiaolan Tian
- Institute of Seafood, Zhejiang Gongshang University, Hangzhou 310012, PR China
| | - Junli Feng
- Institute of Seafood, Zhejiang Gongshang University, Hangzhou 310012, PR China.,Key Lab of aquatic Products Processing of Zhejiang Province, Hangzhou 310012, PR China
| | - Yi Wang
- Institute of Seafood, Zhejiang Gongshang University, Hangzhou 310012, PR China
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8
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Badger S, Abraham S, O'Dea M, Saputra S, Abraham RJ, Worthing KA, Norris JM, Trott DJ, Jordan D, Caraguel CGB. Diagnostic accuracy of phenotypic assays for determining antimicrobial resistance status in Staphylococcus pseudintermedius isolates from canine clinical cases. Vet Microbiol 2019; 234:101-109. [PMID: 31213265 DOI: 10.1016/j.vetmic.2019.05.024] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 05/27/2019] [Accepted: 05/29/2019] [Indexed: 01/20/2023]
Abstract
This study evaluated the diagnostic test accuracy of disc diffusion relative to broth-microdilution for clinical Staphylococcus pseudintermedius isolated from dogs in Australia (n = 614). Accuracy of disc diffusion and broth-microdilution for oxacillin relative to mecA real-time PCR was also assessed. Each isolate had paired minimum inhibitory concentration and zone diameter values for ten antimicrobial agents. Data was dichotomised using Clinical and Laboratory Standards Institute susceptible and resistant clinical breakpoints. Test accuracy was reported using relative diagnostic sensitivity (RSe), specificity (RSp), likelihood ratio pairs, diagnostic odds ratio, and area-under-the receiver-operating characteristic (ROC AUC) analysis. Disc diffusion was found to have high test accuracy for most antimicrobials (ROC AUC range: 0.96 - 0.99) except rifampicin (ROC AUC = 0.80). The RSp of disc diffusion was high for all antimicrobials (range, 97.1%-100%). However, RSe was considerably variable (range, 35.7%-98.8%), particularly for amoxicillin-clavulanic acid (51.5%, 95% CI, 38.9%, 64.0%), cefoxitin (35.7%, 95% CI, 12.8%, 64.9%), and cephalothin (43.6%, 95% CI, 27.8%, 60.4%). When disc diffusion and broth-microdilution were compared to mecA real-time PCR, the overall accuracy of both assays was similar (ROC AUC, 0.99 respectively). However, the RSe for broth-microdilution (96.1%, 95% CI, 88.9%, 99.2%) was significantly higher than for disc diffusion (86.8%, 95% CI, 77.1%, 93.5%) (McNemars mid-p value 0.01). Overall, these findings demonstrate that for most antimicrobials, disc diffusion performed according to CLSI guidelines can be used to differentiate clinical S. pseudintermedius isolates that might otherwise be assessed by broth-microdilution, provided consideration is given to the performance estimates reported here.
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Affiliation(s)
- Skye Badger
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, 5371, Australia; School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Perth, Western Australia, 6150, Australia.
| | - Sam Abraham
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, 5371, Australia.
| | - Mark O'Dea
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Perth, Western Australia, 6150, Australia. M.O'
| | - Sugiyono Saputra
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, 5371, Australia.
| | - Rebecca J Abraham
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, 5371, Australia.
| | - Kate A Worthing
- University of Sydney, Sydney School of Veterinary Science, NSW, Australia; Department of Microbiology and Immunology, at the Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Victoria, Australia.
| | | | - Darren J Trott
- Australian Centre for Antimicrobial Resistance Ecology, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, 5371, Australia.
| | - David Jordan
- School of Veterinary and Life Sciences, Murdoch University, 90 South Street, Murdoch, Perth, Western Australia, 6150, Australia; Wollongbar Primary Industries Institute, NSW Department of Primary Industries, 1243 Bruxner Highway, Wollongbar, New South Wales, 2477, Australia.
| | - Charles G B Caraguel
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, 5371, Australia.
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Wang H, Hecht S, Kline D, Leber AL. Staphylococcus aureus and methicillin resistance detection directly from pediatric samples using PCR assays with differential cycle threshold values for corroboration of methicillin resistance. J Microbiol Methods 2019; 159:167-173. [PMID: 30826439 DOI: 10.1016/j.mimet.2019.01.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 01/15/2019] [Accepted: 01/20/2019] [Indexed: 01/13/2023]
Abstract
Staphylococcus aureus is a major human pathogen, causing a variety of nosocomial and community-acquired infections. While S. aureus usually grows well, there are situations where it cannot be isolated in culture, such as patients who have received prior antimicrobial therapy. There are commercially available tests for molecular identification of S. aureus and methicillin resistance; however, they often have limited utility due to restrictive specimen requirements, lack of data in pediatric populations and issues with specificity for methicillin resistance detections. Our objective was to evaluate the performance of laboratory-developed PCR assays that detect S. aureus and methicillin resistance directly from various specimen types. We developed two real-time PCR assays: 1) a singleplex assay targeting the nucA gene and 2) a multiplex PCR assay (mecA/SCC-orf PCRs) that detects the mecA gene and the conjunction region where SCCmec elements insert into the genome. A total of 538 pediatric specimens, including specimens from the lower respiratory tract (n = 149), abscess/wounds (n = 245), tissue and body fluids (n = 144), were tested and the results compared with culture and susceptibility testing. The nucA PCR is sensitive and specific for detection of S. aureus when compared with culture with an overall agreement of 93.1% and sensitivity and specificity of 93.5% and 93.0%, respectively. Among those culture-confirmed and nucA PCR positive specimens (n = 145), concordance between mecA/SCC-orf PCRs, using cycle threshold values for corroboration, and conventional methods was 98.6% and the sensitivity and specificity were 97.3% and 100%, respectively. The assays' performance suggests they are rapid, reliable tools to detect and differentiate between methicillin susceptible and methicillin resistant S. aureus in our pediatric patient population providing diagnostic impact when used in conjunction with culture.
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Affiliation(s)
- Huanyu Wang
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital and The Ohio State University, Columbus, OH, United States of America
| | - Shaina Hecht
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Nationwide Children's Hospital and The Ohio State University, Columbus, OH, United States of America
| | - David Kline
- Department of Biomedical Informatics, The Ohio State University, Columbus, OH, United States of America
| | - Amy L Leber
- Department of Pathology and Laboratory Medicine, Nationwide Children's Hospital and The Ohio State University, Columbus, OH, United States of America.
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10
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Laman M, Greenhill A, Coombs GW, Robinson O, Pearson J, Davis TME, Manning L. Methicillin-resistant Staphylococcus aureus in Papua New Guinea: a community nasal colonization prevalence study. Trans R Soc Trop Med Hyg 2018; 111:360-362. [PMID: 29237065 DOI: 10.1093/trstmh/trx061] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/23/2017] [Indexed: 11/13/2022] Open
Abstract
Background There are few epidemiological data available to inform a national response to community-acquired methicillin-resistant Staphylococcus aureus (MRSA) in Papua New Guinea (PNG). Methods We performed a cross-sectional survey to determine the pattern of MRSA nasal colonization and the diversity of circulating MRSA clones among adults and adolescents in Madang Province, PNG. Results S. aureus nasal colonization was confirmed in 44 (17.1%) of 257 participants. Four (9.1%) isolates were methicillin resistant. Resistance to other antimicrobial agents was uncommon. Detailed molecular typing of three MRSA isolates demonstrated multiple MRSA clones in this community, of which two carried the Panton-Valentin leukocidin-associated virulence genes. Conclusions MRSA is likely to account for a clinically important proportion of staphylococcal disease in PNG. There are multiple MRSA clones in PNG. Ongoing surveillance of community and invasive isolates is a critical component of an effective response to the challenge of community-acquired MRSA in this and many other resource-limited contexts.
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Affiliation(s)
- Moses Laman
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea.,School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - Andrew Greenhill
- Papua New Guinea Institute of Medical Research, Madang, Madang Province, Papua New Guinea.,School of Applied and Biomedical Sciences, Federation University Australia, Gippsland, Victoria, Australia
| | - Geoffrey W Coombs
- PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia.,School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Owen Robinson
- PathWest Laboratory Medicine WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia.,School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia.,Department of Infectious Diseases, Fiona Stanley Hospital, Murdoch, Western Australia, Australia.,Department of Infectious Diseases, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Julie Pearson
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Timothy M E Davis
- School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - Laurens Manning
- School of Medicine and Pharmacology, University of Western Australia, Harry Perkins Research Institute, Fiona Stanley Hospital, Murdoch, Western Australia, Australia.,Department of Infectious Diseases, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
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11
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Misidentification of Staphylococcus aureus by the Cepheid Xpert MRSA/SA BC Assay Due to Deletions in the spa Gene. J Clin Microbiol 2018; 56:JCM.00530-18. [PMID: 29743311 DOI: 10.1128/jcm.00530-18] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Geng Y, Liu S, Wang J, Nan H, Liu L, Sun X, Li D, Liu M, Wang J, Tan K. Rapid Detection of Staphylococcus aureus in Food Using a Recombinase Polymerase Amplification-Based Assay. FOOD ANAL METHOD 2018. [DOI: 10.1007/s12161-018-1267-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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13
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Tat Trung N, Van Tong H, Lien TT, Van Son T, Thanh Huyen TT, Quyen DT, Hoan PQ, Meyer CG, Song LH. Clinical utility of an optimised multiplex real-time PCR assay for the identification of pathogens causing sepsis in Vietnamese patients. Int J Infect Dis 2017; 67:122-128. [PMID: 29253706 DOI: 10.1016/j.ijid.2017.12.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2017] [Revised: 12/07/2017] [Accepted: 12/09/2017] [Indexed: 11/30/2022] Open
Abstract
INTRODUCTION For the identification of bacterial pathogens, blood culture is still the gold standard diagnostic method. However, several disadvantages apply to blood cultures, such as time and rather large volumes of blood sample required. We have previously established an optimised multiplex real-time PCR method in order to diagnose bloodstream infections. MATERIAL AND METHODS In the present study, we evaluated the diagnostic performance of this optimised multiplex RT-PCR in blood samples collected from 110 septicaemia patients enrolled at the 108 Military Central Hospital, Hanoi, Vietnam. RESULTS Positive results were obtained by blood culture, the Light Cylcler-based SeptiFast® assay and our multiplex RT-PCR in 35 (32%), 31 (28%), and 31 (28%) samples, respectively. Combined use of the three methods confirmed 50 (45.5%) positive cases of bloodstream infection, a rate significantly higher compared to the exclusive use of one of the three methods (P=0.052, 0.012 and 0.012, respectively). The sensitivity, specificity and area under the curve (AUC) of our assay were higher compared to that of the SeptiFast® assay (77.4%, 86.1% and 0.8 vs. 67.7%, 82.3% and 0.73, respectively). Combined use of blood culture and multiplex RT-PCR assay showed a superior diagnostic performance, as the sensitivity, specificity, and AUC reached 83.3%, 100%, and 0.95, respectively. The concordance between blood culture and the multiplex RT-PCR assay was highest for Klebsiella pneumonia (100%), followed by Streptococcus spp. (77.8%), Escherichia coli (66.7%), Staphylococcus spp. (50%) and Salmonella spp. (50%). In addition, the use of the newly established multiplex RT-PCR assay increased the spectrum of identifiable agents (Acintobacter baumannii, 1/32; Proteus mirabilis, 1/32). CONCLUSION The combination of culture and the multiplex RT-PCR assay provided an excellent diagnostic accomplishment and significantly supported the identification of causative pathogens in clinical samples obtained from septic patients.
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Affiliation(s)
- Ngo Tat Trung
- Department of Molecular Biology, 108 Military Central Hospital, No 1, Tran Hung Dao Street, Hai Ba Trung Dist, Hanoi, Vietnam; Vietnamese - German Centre for Medical Research (VG-CARE), Hanoi, Vietnam.
| | - Hoang Van Tong
- Vietnamese - German Centre for Medical Research (VG-CARE), Hanoi, Vietnam; Biomedical and Pharmaceutical Applied Research Center, Vietnam Military Medical University, Hanoi, Vietnam.
| | - Tran Thi Lien
- Faculty of Infectious diseases, Hai Phong Medical University, 72A Nguyen Binh Khiem, Ngo Quyen District, Hai Phong, Vietnam.
| | - Trinh Van Son
- Vietnamese - German Centre for Medical Research (VG-CARE), Hanoi, Vietnam; Institute of Clinical Infectious Diseases, 108 Military Central Hospital, No 1, Tran Hung Dao Street, Hai Ba Trung Dist, Hanoi, Vietnam.
| | - Tran Thi Thanh Huyen
- Department of Molecular Biology, 108 Military Central Hospital, No 1, Tran Hung Dao Street, Hai Ba Trung Dist, Hanoi, Vietnam.
| | - Dao Thanh Quyen
- Department of Molecular Biology, 108 Military Central Hospital, No 1, Tran Hung Dao Street, Hai Ba Trung Dist, Hanoi, Vietnam.
| | - Phan Quoc Hoan
- Department of Molecular Biology, 108 Military Central Hospital, No 1, Tran Hung Dao Street, Hai Ba Trung Dist, Hanoi, Vietnam.
| | - Christian G Meyer
- Vietnamese - German Centre for Medical Research (VG-CARE), Hanoi, Vietnam; Institute of Tropical Medicine, Eberhard Karls University Tübingen, Wilhelmstr. 27, 72074, Tübingen, Germany; Faculty of Medicine, Duy Tan University, Da Nang, Vietnam.
| | - Le Huu Song
- Vietnamese - German Centre for Medical Research (VG-CARE), Hanoi, Vietnam; Institute of Clinical Infectious Diseases, 108 Military Central Hospital, No 1, Tran Hung Dao Street, Hai Ba Trung Dist, Hanoi, Vietnam.
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McIver CJ, Tjandra FA, Er N, Taylor PC. A novel quantitative PCR assay for testing bacteria directly from plate cultures using SYBR Green technology. Pathology 2017; 49:658-660. [DOI: 10.1016/j.pathol.2017.06.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2017] [Revised: 06/01/2017] [Accepted: 06/06/2017] [Indexed: 10/19/2022]
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Accurate Detection of Methicillin-Resistant Staphylococcus aureus in Mixtures by Use of Single-Bacterium Duplex Droplet Digital PCR. J Clin Microbiol 2017; 55:2946-2955. [PMID: 28724560 DOI: 10.1128/jcm.00716-17] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 07/14/2017] [Indexed: 12/16/2022] Open
Abstract
Accurate and rapid identification of methicillin-resistant Staphylococcus aureus (MRSA) is needed to screen MRSA carriers and improve treatment. The current widely used duplex PCR methods are not able to differentiate MRSA from coexisting methicillin-susceptible S. aureus (MSSA) or other methicillin-resistant staphylococci. In this study, we aimed to develop a direct method for accurate and rapid detection of MRSA in clinical samples from open environments, such as nasal swabs. The new molecular assay is based on detecting the cooccurrence of nuc and mecA markers in a single bacterial cell by utilizing droplet digital PCR (ddPCR) with the chimeric lysin ClyH for cell lysis. The method consists of (i) dispersion of an intact single bacterium into nanoliter droplets, (ii) temperature-controlled release of genomic DNA (gDNA) by ClyH at 37°C, and (iii) amplification and detection of the markers (nuc and mecA) using standard TaqMan chemistries with ddPCR. Results were analyzed based on MRSA index ratios used for indicating the presence of the duplex-positive markers in droplets. The method was able to achieve an absolute limit of detection (LOD) of 2,900 CFU/ml for MRSA in nasal swabs spiked with excess amounts of Escherichia coli, MSSA, and other mecA-positive bacteria within 4 h. Initial testing of 104 nasal swabs showed that the method had 100% agreement with the standard culture method, while the normal duplex qPCR method had only about 87.5% agreement. The single-bacterium duplex ddPCR assay is rapid and powerful for more accurate detection of MRSA directly from clinical specimens.
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16
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Sahibzada S, Abraham S, Coombs GW, Pang S, Hernández-Jover M, Jordan D, Heller J. Transmission of highly virulent community-associated MRSA ST93 and livestock-associated MRSA ST398 between humans and pigs in Australia. Sci Rep 2017; 7:5273. [PMID: 28706213 PMCID: PMC5509732 DOI: 10.1038/s41598-017-04789-0] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 05/19/2017] [Indexed: 12/13/2022] Open
Abstract
Pigs have been recognised as a reservoir of livestock associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in Europe, Asia and North America. However, little is known about the presence and distribution of MRSA in the Australian pig population and pig industry. This study describes the presence, distribution and molecular characteristics of the human adapted Australian CA-MRSA ST93 isolated from pigs, people, and the environment within a piggery. Isolates were subjected to antibiotic susceptibility testing, DNA microarray, whole genome sequencing, multi locus sequence typing, virulence and resistance gene characterization and phylogenetic analysis. MRSA were isolated from 60% (n = 52) of farm workers where 84% of isolates returned ST93 and the rest ST398. Of the thirty-one pig isolates tested further, an equal number of ST398 and ST93 (15 each) and one as ST30-V were identified. Four of six environmental isolates were identified as ST93 and two as ST398. This study has identified for the first time in Australia the occurrence of CA-MRSA ST93 and LA-MRSA ST398 amongst farm workers, pigs, and the farm environment. Comparative genome analysis indicates that ST398 is likely to have been introduced into Australia from Europe or North America. This study also reports the first linezolid resistant MRSA isolated in Australia.
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Affiliation(s)
- S Sahibzada
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
- Graham Centre for Agricultural Innovation, Wagga Wagga, Australia
| | - S Abraham
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | - G W Coombs
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
- PathWest Laboratory Medicine - WA, Fiona Stanley Hospital, Murdoch, Australia
| | - S Pang
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
- PathWest Laboratory Medicine - WA, Fiona Stanley Hospital, Murdoch, Australia
| | - M Hernández-Jover
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia
- Graham Centre for Agricultural Innovation, Wagga Wagga, Australia
| | - D Jordan
- Department of Primary Industries, Wollongbar, NSW 2478, Australia
| | - J Heller
- School of Animal and Veterinary Sciences, Charles Sturt University, Wagga Wagga, NSW 2678, Australia.
- Graham Centre for Agricultural Innovation, Wagga Wagga, Australia.
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17
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Giufrè M, Ricchizzi E, Accogli M, Barbanti F, Monaco M, Pimentel de Araujo F, Farina C, Fazii P, Mattei R, Sarti M, Barozzi A, Buttazzi R, Cosentino M, Nardone M, Savini V, Spigaglia P, Pantosti A, Moro ML, Cerquetti M. Colonization by multidrug-resistant organisms in long-term care facilities in Italy: a point-prevalence study. Clin Microbiol Infect 2017; 23:961-967. [PMID: 28412380 DOI: 10.1016/j.cmi.2017.04.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 03/30/2017] [Accepted: 04/06/2017] [Indexed: 11/24/2022]
Abstract
OBJECTIVES To determine prevalence and risk factors for colonization by multidrug-resistant organisms (MDROs) in long-term care facility (LTCF) residents in Italy. Genotypes of MDRO isolates were investigated. METHODS A point-prevalence study was conducted at 12 LTCFs located in four Italian cities (2 February to 14 March 2015). Rectal swabs, faeces and nasal/auxiliary swabs were cultured for extended-spectrum β-lactamase (ESBL)- and/or carbapenemase-producing Enterobacteriaceae, Clostridium difficile and methicillin-resistant Staphylococcus aureus (MRSA) respectively. Antimicrobial susceptibility testing, detection of ESBL and/or carbapenemase genes and molecular typing of MDROs were performed. Risk factors for colonization were determined by univariate and multivariate analysis. RESULTS A total of 489 LTCF residents aged ≥65 years were enrolled. The prevalence of colonization by ESBL-producing Enterobacteriaceae, MRSA and C. difficile was 57.3% (279/487), 17.2% (84/487) and 5.1% (21/409) respectively. Carriage rate of carbapenemase-producing Enterobacteriaceae was 1% (5/487). Being bedridden was a common independent risk factor for colonization by all MDROs, although risk factors specific for each MDRO were identified. ESBL-producing Escherichia coli carriage was associated with the sequence type (ST) 131-H30 subclone, but other minor STs predominated in individual LTCF or in LTCFs located in the same city, suggesting a role for intrafacility or local transmission. Similarly, MRSA from LTCF residents belonged to the same spa types/ST clones (t008/ST8 and t032/ST22) commonly found in Italian acute-care hospitals, but infrequent spa types were recovered in individual LTCFs. The prevalent C. difficile PCR ribotypes were 356/607 and 018, both common in Italian acute-care hospitals. CONCLUSIONS MDRO colonization is common among residents in Italian LTCFs.
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Affiliation(s)
- M Giufrè
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - E Ricchizzi
- Health and Social Agency, Emilia-Romagna Region, Bologna, Italy
| | - M Accogli
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - F Barbanti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - M Monaco
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | | | - C Farina
- Papa Giovanni XXIII Hospital, Bergamo, Italy
| | - P Fazii
- Spirito Santo Hospital, Pescara, Italy
| | - R Mattei
- Campo di Marte Hospital, Lucca, Italy
| | - M Sarti
- S. Agostino-Estense-Baggiovara Hospital, Modena, Italy
| | - A Barozzi
- S. Agostino-Estense-Baggiovara Hospital, Modena, Italy
| | - R Buttazzi
- Health and Social Agency, Emilia-Romagna Region, Bologna, Italy
| | - M Cosentino
- Papa Giovanni XXIII Hospital, Bergamo, Italy
| | - M Nardone
- Campo di Marte Hospital, Lucca, Italy
| | - V Savini
- Spirito Santo Hospital, Pescara, Italy
| | - P Spigaglia
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - A Pantosti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - M L Moro
- Health and Social Agency, Emilia-Romagna Region, Bologna, Italy
| | - M Cerquetti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy.
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18
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Basanisi MG, La Bella G, Nobili G, Franconieri I, La Salandra G. Genotyping of methicillin-resistant Staphylococcus aureus (MRSA) isolated from milk and dairy products in South Italy. Food Microbiol 2016; 62:141-146. [PMID: 27889140 DOI: 10.1016/j.fm.2016.10.020] [Citation(s) in RCA: 101] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 10/03/2016] [Accepted: 10/08/2016] [Indexed: 12/18/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a pathogen emerging in hospitals as well as community and livestock. MRSA is a significant and costly public health concern because it may enter the human food chain and contaminate milk and dairy products causing foodborne illness. This study aimed to determine the occurrence and the characteristics of MRSA isolated from 3760 samples of milk and dairy products in a previous survey conducted in southern Italy during 2008-2014. Overall out of 484 S. aureus strains isolated, 40 (8.3%) were MRSA and were characterized by spa-typing, Multi-Locus Sequence Typing, SCCmec typing, Staphylococcal enterotoxins (SEs) genes, Panton-Valentine Leukocidin (PVL) genes and ability to form biofilm. The most frequently recovered STs were ST152 (t355-67.5%), followed by ST398 (t899, t108-25%), ST1 (t127-5%) and ST5 (t688-2.5%). All isolates harboured the SCCmec type V (92.5%) or IVa (25%). In one isolate (2.5%), ST398/t899, the SCCmec resulted not detected. Three isolates (7.5%) carried one or more enterotoxin encoding genes (one strain had seg, sei, sem, sen and seo genes; two strains had seh gene). The 50% of isolated strains harboured PVL-encoding genes. Molecular analysis for icaA and icaD genes showed: 72.5% icaA and icaD positive, 25% only icaD gene and one icaA and icaD negative. The detection of MRSA in food of animal origin is a potential health hazard, thus it is necessary monitoring of food-producing animals and improving hygiene standards in food practices in order to reduce the microbiological risk to minimum.
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Affiliation(s)
- M G Basanisi
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia, 20, 71121 Foggia, Italy
| | - G La Bella
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia, 20, 71121 Foggia, Italy
| | - G Nobili
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia, 20, 71121 Foggia, Italy
| | - I Franconieri
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia, 20, 71121 Foggia, Italy
| | - G La Salandra
- Istituto Zooprofilattico Sperimentale della Puglia e della Basilicata, Via Manfredonia, 20, 71121 Foggia, Italy.
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19
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Basanisi M, Nobili G, La Bella G, Russo R, Spano G, Normanno G, La Salandra G. Molecular characterization of Staphylococcus aureus isolated from sheep and goat cheeses in southern Italy. Small Rumin Res 2016. [DOI: 10.1016/j.smallrumres.2015.12.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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20
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Groves MD, Crouch B, Coombs GW, Jordan D, Pang S, Barton MD, Giffard P, Abraham S, Trott DJ. Molecular Epidemiology of Methicillin-Resistant Staphylococcus aureus Isolated from Australian Veterinarians. PLoS One 2016; 11:e0146034. [PMID: 26735694 PMCID: PMC4703204 DOI: 10.1371/journal.pone.0146034] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/12/2015] [Indexed: 11/19/2022] Open
Abstract
This work investigated the molecular epidemiology and antimicrobial resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolated from veterinarians in Australia in 2009. The collection (n = 44) was subjected to extensive molecular typing (MLST, spa, SCCmec, dru, PFGE, virulence and antimicrobial resistance genotyping) and antimicrobial resistance phenotyping by disk diffusion. MRSA was isolated from Australian veterinarians representing various occupational emphases. The isolate collection was dominated by MRSA strains belonging to clonal complex (CC) 8 and multilocus sequence type (ST) 22. CC8 MRSA (ST8-IV [2B], spa t064; and ST612-IV [2B], spa variable,) were strongly associated with equine practice veterinarians (OR = 17.5, 95% CI = 3.3–92.5, P < 0.001) and were often resistant to gentamicin and rifampicin. ST22-IV [2B], spa variable, were strongly associated with companion animal practice veterinarians (OR = 52.5, 95% CI = 5.2–532.7, P < 0.001) and were resistant to ciprofloxacin. A single pig practice veterinarian carried ST398-V [5C2], spa t1451. Equine practice and companion animal practice veterinarians frequently carried multiresistant-CC8 and ST22 MRSA, respectively, whereas only a single swine specialist carried MRSA ST398. The presence of these strains in veterinarians may be associated with specific antimicrobial administration practices in each animal species.
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Affiliation(s)
- Mitchell D. Groves
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
| | - Bethany Crouch
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Geoffrey W. Coombs
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
- Department of Microbiology, Path West Laboratory Medicine, WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - David Jordan
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
- New South Wales Department of Primary Industries, Wollongbar, New South Wales, Australia
| | - Stanley Pang
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
- Department of Microbiology, Path West Laboratory Medicine, WA, Fiona Stanley Hospital, Murdoch, Western Australia, Australia
| | - Mary D. Barton
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Phil Giffard
- Menzies School of Health Research, Casuarina, Northern Territory, Australia
| | - Sam Abraham
- School of Veterinary and Life Sciences, Murdoch University, Murdoch, Australia
- * E-mail: (SA); (DT)
| | - Darren J. Trott
- School of Animal and Veterinary Sciences, The University of Adelaide, Roseworthy, South Australia, Australia
- * E-mail: (SA); (DT)
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Boan P, Tan HL, Pearson J, Coombs G, Heath CH, Robinson JO. Epidemiological, clinical, outcome and antibiotic susceptibility differences between PVL positive and PVL negative Staphylococcus aureus infections in Western Australia: a case control study. BMC Infect Dis 2015; 15:10. [PMID: 25572896 PMCID: PMC4297412 DOI: 10.1186/s12879-014-0742-6] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 12/23/2014] [Indexed: 12/13/2022] Open
Abstract
Background Panton Valentine Leukocidin (PVL) has been associated with invasive Staphylococcus aureus soft tissue and pneumonic infections. Methods From September 2007 to January 2009 at Royal Perth Hospital we tested for the PVL gene in S. aureus isolates from an invasive site, a suspected PVL-related soft tissue infection and all MRSA isolates. We could access medical records for 141 PVL positive (PVL + ve) infections and compared these to a control group comprised of 148 PVL negative (PVL-ve) infections. Results In the PVL + ve group 62 isolates were MRSA (48 were ST93-MRSA-IV) and 79 isolates were methicillin-sensitive S. aureus, and in the PVL-ve group 56 were MRSA (50 were WA-MRSA strains) and 92 were methicillin-sensitive S. aureus. We found the presence of PVL to be significantly associated with younger age, aboriginality, intravenous drug use, community acquisition, shorter length of hospital stay and lower mortality at 1 year. Overall PVL + ve infections more often required surgical intervention (73.0% versus 44.6%, p < 0.001) and were less often polymicrobial (8.5% versus 41.2%, p < 0.001). PVL + ve isolates were more often susceptible to clindamycin (87.9% versus 73.0%, p = 0.002). Conclusions This study demonstrates that PVL + ve infections are associated with a distinct clinical picture, predominantly pyogenic skin and soft tissue infections often requiring surgery, disproportionately affecting patients who are younger, indigenous or with fewer health-care risk factors.
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Affiliation(s)
- Peter Boan
- Department of Microbiology and Infectious Diseases and PathWest Laboratory Medicine WA, Royal Perth Hospital, Wellington St, Perth, WA, 6000, Australia.
| | - Hui-Leen Tan
- Department of Microbiology and Infectious Diseases and PathWest Laboratory Medicine WA, Royal Perth Hospital, Wellington St, Perth, WA, 6000, Australia. .,Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, PathWest Laboratory Medicine WA and Curtin University of Technology, GPO Box X2213, Perth, WA, 6847, Australia.
| | - Julie Pearson
- Department of Microbiology and Infectious Diseases and PathWest Laboratory Medicine WA, Royal Perth Hospital, Wellington St, Perth, WA, 6000, Australia. .,Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, PathWest Laboratory Medicine WA and Curtin University of Technology, GPO Box X2213, Perth, WA, 6847, Australia.
| | - Geoffrey Coombs
- Department of Microbiology and Infectious Diseases and PathWest Laboratory Medicine WA, Royal Perth Hospital, Wellington St, Perth, WA, 6000, Australia. .,Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, PathWest Laboratory Medicine WA and Curtin University of Technology, GPO Box X2213, Perth, WA, 6847, Australia.
| | - Christopher H Heath
- Department of Microbiology and Infectious Diseases and PathWest Laboratory Medicine WA, Royal Perth Hospital, Wellington St, Perth, WA, 6000, Australia.
| | - James Owen Robinson
- Department of Microbiology and Infectious Diseases and PathWest Laboratory Medicine WA, Royal Perth Hospital, Wellington St, Perth, WA, 6000, Australia. .,Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, PathWest Laboratory Medicine WA and Curtin University of Technology, GPO Box X2213, Perth, WA, 6847, Australia.
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da Costa Krewer C, Santos Amanso E, Veneroni Gouveia G, de Lima Souza R, da Costa MM, Aparecido Mota R. Resistance to antimicrobials and biofilm formation in Staphylococcus spp. isolated from bovine mastitis in the Northeast of Brazil. Trop Anim Health Prod 2014; 47:511-8. [DOI: 10.1007/s11250-014-0752-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 12/16/2014] [Indexed: 11/28/2022]
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23
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Ravens PA, Vogelnest LJ, Ewen E, Bosward KI, Norris JM. Canine superficial bacterial pyoderma: evaluation of skin surface sampling methods and antimicrobial susceptibility of causal Staphylococcus isolates. Aust Vet J 2014; 92:149-55. [PMID: 24766044 DOI: 10.1111/avj.12176] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2013] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate three easily performed methods of skin surface sampling for bacterial culture of Staphylococcus isolates obtained from dogs with superficial bacterial pyoderma (SBP) presenting to two veterinary teaching hospitals in Sydney, Australia, and to determine the antimicrobial susceptibility of isolates. DESIGN Prospective study of 27 dogs with SBP. Cytologically confirmed SBP lesions were sampled for bacterial culture using a dry cotton swab, a saline-moistened cotton swab and a skin surface scraping. Isolates were identified by standard discriminatory phenotypic and biochemical analyses, and confirmed using matrix-assisted laser desorption ionisation time of flight mass spectrometry (MALDI-TOF MS). Susceptibilities to 14 antimicrobials were determined by disk diffusion and by detection of the mecA gene using PCR. Sampling methods were compared according to bacterial yield, antibiograms and bacterial phenotypic analysis. Location of causative bacteria was evaluated via 8-mm punch skin biopsies using haematoxylin and eosin, Gram-Twort and Giemsa staining, and fluorescence in situ hybridisation (FISH). RESULTS Staphylococcus sp. were isolated from lesions in all dogs, either S. pseudintermedius (24 dogs) or S. schleiferi (3 dogs). Susceptibility was highest to cephalexin (96%) and amoxycillin clavulanate (96%). Methicillin resistance assessed by mecA real-time PCR and phenotypic oxacillin resistance was found in one dog (4.3%). Routine histology and FISH revealed bacteria within superficial stratum corneum. CONCLUSION Staphylococcal isolates from canine SBP demonstrated high susceptibility to common empirical antimicrobials. Histological techniques confirmed presence of bacteria at superficial sites, likely to be accessed by the sampling techniques. The three techniques afforded similar results and may be equally suitable for obtaining samples for culture.
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Affiliation(s)
- P A Ravens
- Faculty of Veterinary Science, The University of Sydney, Sydney, New South Wales, Australia
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Chudobova D, Cihalova K, Skalickova S, Zitka J, Rodrigo MAM, Milosavljevic V, Hynek D, Kopel P, Vesely R, Adam V, Kizek R. 3D-printed chip for detection of methicillin-resistant Staphylococcus aureus labeled with gold nanoparticles. Electrophoresis 2014; 36:457-66. [PMID: 25069433 DOI: 10.1002/elps.201400321] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 07/22/2014] [Accepted: 07/22/2014] [Indexed: 12/29/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a dangerous pathogen occurring not only in hospitals but also in foodstuff. Currently, discussions on the issue of the increasing resistance, and timely and rapid diagnostic of resistance strains have become more frequent and sought. Therefore, the aim of this study was to design an effective platform for DNA isolation from different species of microorganisms as well as the amplification of mecA gene that encodes the resistance to β-lactam antibiotic formation and is contained in MRSA. For this purpose, we fabricated 3D-printed chip that was suitable for bacterial cultivation, DNA isolation, PCR, and detection of amplified gene using gold nanoparticle (AuNP) probes as an indicator of MRSA. Confirmation of the MRSA presence in the samples was based on a specific interaction between mecA gene with the AuNP probes and a colorimetric detection, which utilized the noncross-linking aggregation phenomenon of DNA-functionalized AuNPs. To test the whole system, we analyzed several real refractive indexes, in which two of them were positively scanned to find the presence of mecA gene. The aggregation of AuNP probes were reflected by 75% decrease of absorbance (λ = 530 nm) and change in AuNPs size from 3 ± 0.05 to 4 ± 0.05 nm (n = 5). We provide the one-step identification of mecA gene using the unique platform that employs the rapid, low-cost, and easy-to-use colorimetric method for MRSA detection in various samples.
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Affiliation(s)
- Dagmar Chudobova
- Department of Chemistry and Biochemistry, Mendel University in Brno, Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technicka, Brno, Czech Republic
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Siak M, Burrows AK, Coombs GW, Khazandi M, Abraham S, Norris JM, Weese JS, Trott DJ. Characterization of meticillin-resistant and meticillin-susceptible isolates of Staphylococcus pseudintermedius from cases of canine pyoderma in Australia. J Med Microbiol 2014; 63:1228-1233. [DOI: 10.1099/jmm.0.076117-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Meticillin-resistant Staphylococcus pseudintermedius (MRSP) has recently emerged as a worldwide cause of canine pyoderma. In this study, we characterized 22 S. pseudintermedius isolates cultured from 19 dogs with pyoderma that attended a veterinary dermatology referral clinic in Australia in 2011 and 2012. Twelve isolates were identified as MRSP by mecA real-time PCR and phenotypic resistance to oxacillin. In addition to β-lactam resistance, MRSP isolates were resistant to erythromycin (91.6 %), gentamicin (83.3 %), ciprofloxacin (83.3 %), chloramphenicol (75 %), clindamycin (66 %), oxytetracycline (66 %) and tetracycline (50 %), as shown by disc-diffusion susceptibility testing. Meticillin-susceptible S. pseudintermedius isolates only showed resistance to penicillin/ampicillin (90 %) and tetracycline (10 %). PFGE using the SmaI restriction enzyme was unable to type nine of the 12 MRSP isolates. However the nine isolates provided the same PFGE pulsotype using the Cfr91 restriction enzyme. Application of the mec-associated direct repeat unit (dru) typing method identified the nine SmaI PFGE-untypable isolates as dt11cb, a dru type that has only previously been associated with MRSP sequence type (ST)45 isolates that possess a unique SCCmec element. The dt11cb isolates shared a similar multidrug-resistant antibiogram phenotype profile, whereas the other MRSP isolates, dt11a, dt11af (dt11a-associated) and dt10h, were resistant to fewer antibiotic classes and had distinct PFGE profiles. This is the first report of MRSP causing pyoderma in dogs from Australia. The rapid intercontinental emergence and spread of multidrug-resistant MRSP strains confirms the urgent need for new treatment modalities for recurrent canine pyoderma in veterinary practice.
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Affiliation(s)
- Meng Siak
- Animal Dermatology Clinic – Perth, Murdoch Veterinary Hospital, School of Veterinary and Biomedical Science, Murdoch University, Murdoch, WA, Australia
| | - Amanda K. Burrows
- Animal Dermatology Clinic – Perth, Murdoch Veterinary Hospital, School of Veterinary and Biomedical Science, Murdoch University, Murdoch, WA, Australia
| | - Geoffrey W. Coombs
- Department of Microbiology and Infectious Diseases, PathWest Laboratory Medicine – WA, Royal Perth Hospital, Wellington Street, Perth, WA, Australia
- Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Biomedical Sciences, Curtin University, Perth, WA, Australia
| | - Manouchehr Khazandi
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, SA, Australia
| | - Sam Abraham
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, SA, Australia
| | | | - J. Scott Weese
- Department of Pathobiology and Centre for Public Health and Zoonoses, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Darren J. Trott
- School of Animal and Veterinary Sciences, University of Adelaide, Roseworthy Campus, Mudla Wirra Rd, Roseworthy, SA, Australia
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Yaw LK, Robinson JO, Ho KM. A comparison of long-term outcomes after meticillin-resistant and meticillin-sensitive Staphylococcus aureus bacteraemia: an observational cohort study. THE LANCET. INFECTIOUS DISEASES 2014; 14:967-75. [PMID: 25185461 DOI: 10.1016/s1473-3099(14)70876-x] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
BACKGROUND Findings from previous studies have suggested that outcomes after meticillin-resistant Staphylococcus aureus (MRSA) bacteraemia are worse than after meticillin-sensitive S. aureus (MSSA) bacteraemia. We assessed whether patients who had MRSA bacteraemia had a higher risk of death and recurrent infections than those who had MSSA bacteraemia. METHODS For this observational cohort study, we assessed data from the microbiology laboratory database at the Royal Perth Hospital (WA, Australia). Data were for all patients who had an episode of MRSA bacteraemia between July 1, 1997, and June 30, 2007, and, by use of a computer-generated randomisation sequence, a randomly selected subgroup of patients who had an episode of MSSA bacteraemia (patients with one or more set of blood cultures positive for S. aureus). The primary outcomes were survival time and subsequent infection-related hospital readmissions, analysed by Cox proportional hazards regression with adjustment for important prognostic factors. FINDINGS Of the 583 patients who had an episode of MRSA or MSSA bacteraemia, we used data for the 582 who had complete data linkage: 185 patients who had MRSA bacteraemia and 397 patients who had MSSA bacteraemia. The crude survival time of patients after MRSA bacteraemia was shorter than it was for patients with MSSA bacteraemia (14 months [IQR 1-86] vs 54 months [3-105]; hazard ratio 1·46, 95% CI 1·18-1·79; p=0·01). The adverse association between MRSA and all-cause mortality (0·98, 0·77-1·30; p=0·87) or infection-related mortality (1·22, 0·89-1·69; p=0·22) were not statistically significant after adjustment for important prognostic factors including age, comorbidities, severity of acute illness, metastatic infections, and long-term care facility resident status. After adjustment for these confounding factors, we saw no difference in infection-related hospital readmissions between patients who had MRSA bacteraemia and those who had MSSA bacteraemia (odds ratio 0·95, 95% CI 0·59-1·53; p=0·83). INTERPRETATION Long-term outcomes after MRSA bacteraemia were worse than those after MSSA bacteraemia through its confounding associations with other prognostic factors. Our findings might have implications for management strategies to control MRSA colonisation. FUNDING The Medical Research Foundation of Royal Perth Hospital.
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Affiliation(s)
- Lai Kin Yaw
- Department of Intensive Care Medicine, Royal Perth Hospital, Perth, WA, Australia.
| | - James Owen Robinson
- Department of Microbiology and Infectious Diseases, Royal Perth Hospital, Perth, WA, Australia; Australian Collaborating Centre for Enterococcus and Staphylococcus Species Typing and Research, School of Biomedical Sciences, Curtin University, Perth, WA, Australia
| | - Kwok Ming Ho
- Department of Intensive Care Medicine, Royal Perth Hospital, Perth, WA, Australia; School of Population Health, University of Western Australia, Perth, WA, Australia
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Rajabiani A, Kamrani F, Boroumand MA, Saffar H. mec-A-mediated Resistance in Staphylococcus aureus in a Referral Hospital, Tehran, Iran. Jundishapur J Microbiol 2014; 7:e9181. [PMID: 25147695 PMCID: PMC4138619 DOI: 10.5812/jjm.9181] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 03/04/2013] [Accepted: 03/14/2013] [Indexed: 11/16/2022] Open
Abstract
Background: The emerge of rapid and accurate detection of Meticillin-Resistant Staphylococcus aureus (MRSA) has been highlighted. Objectives: The current study evaluated the prevalence of mec-A gene in biological specimens of various medical wards, in order to determine any possible relationship. Patients and Methods: Using traditional culture methods, 250 isolates were detected. The prevalence of mec-A mediated resistance was evaluated by PCR method. Results: Among 98 isolates (39.2%) with resistant inhibition zones, 92 isolates carried mec-A gene and were considered as MRSA. Significantly higher rate of MRSA was observed in the specimens from emergency department and intensive care unit (P value < 0.001). Although, the prevalence of MRSA was higher in patients with history of previous hospital admission within the past three months (P = 0.006), but only one case with the same history was hospitalized in the emergency ward that was among the wards with the highest rate of MRSA. Conclusions: The study findings show that, although there is higher rate of MRSA infection in patients with history of hospitalization, but even in cases without any history of medical admission, more detailed questions emphasizing on receiving any recent health care should be asked in a referral hospital, in order to determine the true community-acquired MRSA.
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Affiliation(s)
- Afsaneh Rajabiani
- Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Fatemeh Kamrani
- Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Mohammad Ali Boroumand
- Department of Pathology, Tehran Heart Center, Tehran University of Medical Sciences, Tehran, IR Iran
| | - Hiva Saffar
- Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, IR Iran
- Corresponding author: Hiva Saffar, Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, IR Iran. Tel: +98-2184902195, Fax: +98-2188633078, E-mail:
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Fusco V, Quero GM. Culture-Dependent and Culture-Independent Nucleic-Acid-Based Methods Used in the Microbial Safety Assessment of Milk and Dairy Products. Compr Rev Food Sci Food Saf 2014; 13:493-537. [DOI: 10.1111/1541-4337.12074] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2014] [Accepted: 03/08/2014] [Indexed: 12/12/2022]
Affiliation(s)
- Vincenzina Fusco
- Nal. Research Council of Italy; Inst. of Sciences of Food Production (CNR-ISPA); Bari Italy
| | - Grazia Marina Quero
- Nal. Research Council of Italy; Inst. of Sciences of Food Production (CNR-ISPA); Bari Italy
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Loonen AJM, Wolffs PFG, Bruggeman CA, van den Brule AJC. Developments for improved diagnosis of bacterial bloodstream infections. Eur J Clin Microbiol Infect Dis 2014; 33:1687-702. [PMID: 24848132 DOI: 10.1007/s10096-014-2153-4] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 04/30/2014] [Indexed: 12/26/2022]
Abstract
Bloodstream infections (BSIs) are associated with high mortality and increased healthcare costs. Optimal management of BSI depends on several factors including recognition of the disease, laboratory tests and treatment. Rapid and accurate identification of the etiologic agent is crucial to be able to initiate pathogen specific antibiotic therapy and decrease mortality rates. Furthermore, appropriate treatment might slow down the emergence of antibiotic resistant strains. Culture-based methods are still considered to be the "gold standard" for the detection and identification of pathogens causing BSI. Positive blood cultures are used for Gram-staining. Subsequently, positive blood culture material is subcultured on solid media, and (semi-automated) biochemical testing is performed for species identification. Finally, a complete antibiotic susceptibility profile can be provided based on cultured colonies, which allows the start of pathogen-tailored antibiotic therapy. This conventional workflow is extremely time-consuming and can take up to several days. Furthermore, fastidious and slow-growing microorganisms, as well as antibiotic pre-treated samples can lead to false-negative results. The main aim of this review is to present different strategies to improve the conventional laboratory diagnostic steps for BSI. These approaches include protein-based (MALDI-TOF mass spectrometry) and nucleic acid-based (polymerase chain reaction [PCR]) identification from subculture, blood cultures, and whole blood to decrease time to results. Pathogen enrichment and DNA isolation methods, to enable optimal pathogen DNA recovery from whole blood, are described. In addition, the use of biomarkers as patient pre-selection tools for molecular assays are discussed.
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Affiliation(s)
- A J M Loonen
- Laboratory for Molecular Diagnostics, Department of Medical Microbiology and Pathology, Jeroen Bosch Hospital, 's-Hertogenbosch, The Netherlands
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Velasco V, Sherwood JS, Rojas-García PP, Logue CM. Multiplex real-time PCR for detection of Staphylococcus aureus, mecA and Panton-Valentine Leukocidin (PVL) genes from selective enrichments from animals and retail meat. PLoS One 2014; 9:e97617. [PMID: 24849624 PMCID: PMC4029734 DOI: 10.1371/journal.pone.0097617] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 04/21/2014] [Indexed: 11/21/2022] Open
Abstract
The aim of this study was to compare a real-time PCR assay, with a conventional culture/PCR method, to detect S. aureus, mecA and Panton-Valentine Leukocidin (PVL) genes in animals and retail meat, using a two-step selective enrichment protocol. A total of 234 samples were examined (77 animal nasal swabs, 112 retail raw meat, and 45 deli meat). The multiplex real-time PCR targeted the genes: nuc (identification of S. aureus), mecA (associated with methicillin resistance) and PVL (virulence factor), and the primary and secondary enrichment samples were assessed. The conventional culture/PCR method included the two-step selective enrichment, selective plating, biochemical testing, and multiplex PCR for confirmation. The conventional culture/PCR method recovered 95/234 positive S. aureus samples. Application of real-time PCR on samples following primary and secondary enrichment detected S. aureus in 111/234 and 120/234 samples respectively. For detection of S. aureus, the kappa statistic was 0.68–0.88 (from substantial to almost perfect agreement) and 0.29–0.77 (from fair to substantial agreement) for primary and secondary enrichments, using real-time PCR. For detection of mecA gene, the kappa statistic was 0–0.49 (from no agreement beyond that expected by chance to moderate agreement) for primary and secondary enrichment samples. Two pork samples were mecA gene positive by all methods. The real-time PCR assay detected the mecA gene in samples that were negative for S. aureus, but positive for Staphylococcus spp. The PVL gene was not detected in any sample by the conventional culture/PCR method or the real-time PCR assay. Among S. aureus isolated by conventional culture/PCR method, the sequence type ST398, and multi-drug resistant strains were found in animals and raw meat samples. The real-time PCR assay may be recommended as a rapid method for detection of S. aureus and the mecA gene, with further confirmation of methicillin-resistant S. aureus (MRSA) using the standard culture method.
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Affiliation(s)
- Valeria Velasco
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, North Dakota, United States of America
- Department of Animal Sciences, University of Concepción, Chillán, Chile
| | - Julie S. Sherwood
- Department of Veterinary and Microbiological Sciences, North Dakota State University, Fargo, North Dakota, United States of America
| | - Pedro P. Rojas-García
- Laboratory of Animal Physiology and Endocrinology, Veterinary Sciences, University of Concepción, Chillán, Chile
| | - Catherine M. Logue
- Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa, United States of America
- * E-mail:
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Hoegh SV, Skov MN, Boye K, Worning P, Jensen TG, Kemp M. Variations in the Staphylococcus aureus-specific nuc gene can potentially lead to misidentification of meticillin-susceptible and -resistant S. aureus. J Med Microbiol 2014; 63:1020-1022. [PMID: 24809385 DOI: 10.1099/jmm.0.076638-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- S V Hoegh
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
| | - M N Skov
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
| | - K Boye
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
| | - P Worning
- Department of Clinical Microbiology, Hvidovre Hospital, Hvidovre, Denmark
| | - T G Jensen
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
| | - M Kemp
- Department of Clinical Microbiology, Odense University Hospital, Odense, Denmark
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Coombs GW, Pearson JC, Robinson JO, Christiansen KJ. Activity of ceftaroline against community associated and healthcare associated methicillin resistant Staphylococcus aureus. Pathology 2014; 46:71-3. [PMID: 24300719 DOI: 10.1097/pat.0000000000000032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Geoffrey W Coombs
- 1Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research, School of Biomedical Sciences, Curtin University 2Department of Microbiology and Infectious Diseases, PathWest Laboratory Medicine - WA, Royal Perth Hospital 3Royal Perth Hospital, Perth, WA, Australia
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Pilla R, Castiglioni V, Gelain ME, Scanziani E, Lorenzi V, Anjum M, Piccinini R. Long‐term study of MRSA ST1, t127 mastitis in a dairy cow. VETERINARY RECORD CASE REPORTS 2013. [DOI: 10.1136/vetreccr.100510rep] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- R. Pilla
- Department of Veterinary Pathology, Hygiene and Public HealthUniversità degli Studi di MilanoVia Celoria 1020133MilanoItaly
| | - V. Castiglioni
- Department of Veterinary Pathology, Hygiene and Public HealthUniversità degli Studi di MilanoVia Celoria 1020133MilanoItaly
| | - M. E. Gelain
- Department of Veterinary Pathology, Hygiene and Public HealthUniversità degli Studi di MilanoVia Celoria 1020133MilanoItaly
| | - E. Scanziani
- Department of Veterinary Pathology, Hygiene and Public HealthUniversità degli Studi di MilanoVia Celoria 1020133MilanoItaly
| | - V. Lorenzi
- Department of Veterinary Pathology, Hygiene and Public HealthUniversità degli Studi di MilanoVia Celoria 1020133MilanoItaly
| | - M. Anjum
- Department of BacteriologyTechnology Transfer UnitVeterinary Laboratories Agency‐WeybridgeNew HawAddlestoneSurreyKT15 3NBUK
| | - R. Piccinini
- Department of Veterinary Pathology, Hygiene and Public HealthUniversità degli Studi di MilanoVia Celoria 1020133MilanoItaly
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Pilla R, Bonura C, Malvisi M, Snel GGM, Piccinini R. Methicillin-resistant Staphylococcus pseudintermedius as causative agent of dairy cow mastitis. Vet Rec 2013; 173:19. [PMID: 23723102 DOI: 10.1136/vr.101485] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- R Pilla
- Department of Veterinary Sciences and Public Health, University of Milan, Via Celoria 10, Milano 20133, Italy
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35
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Duplex real-time PCR assay for rapid identification ofStaphylococcus aureusisolates from dairy cow milk. J DAIRY RES 2013; 80:223-6. [DOI: 10.1017/s0022029913000022] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Staphylococcus aureusisolates from dairy cow mastitis are not always consistent with the characteristic morphology described, and molecular investigation is often needed. The aim of the study was to develop a duplex real-time PCR assay for rapid identification ofStaph. aureusisolates, targeting bothnucandSa442. Overall, 140 isolates collected from dairy cow mastitis in 90 different herds, were tested. All strains had been identified using morphological and biochemical characteristics. DNA from each strain was amplified in real-time PCR assay, to detectnucorSa442. Thereafter, a duplex real-time PCR assay was performed, and specificity of the amplified products was assessed by high resolution melting curve analysis. Out of 124Staph. aureusisolates, 33 did not show the typical morphology or enzymic activity; in 118 strains, the two melt-curve peaks consistent withnucandSa442were revealed, while 2 isolates showed only the peak consistent withSa442. Four isolates bacteriologically identified asStaph. aureus, were PCR-negative and were further identified asStaph. pseudintermediusby sequencing.Staph. pseudintermediusand coagulase-negative staphylococci did not carrynucorSa442. The results showed the correct identification of all isolates, comprehending also coagulase—or nuc-negativeStaph. aureus, while other coagulase-positive Staphylococci were correctly identified as non-Staph. aureus. Both sensitivity and specificity were 100%. High resolution melting analysis allowed easy detection of unspecific products. Finally, the duplex real-time PCR was applied directly to 40 milk samples, to detect infected mammary quarters. The assay confirmed the results of bacteriological analysis, onStaph. aureus-positive or—negative samples. Therefore, the proposed duplex real-time PCR could be used in laboratory routine as a cost-effective and powerful tool for high-throughput identification of atypicalStaph. aureusisolates causing dairy cow mastitis. Also, it could be applied directly to milk samples, to detectStaph. aureusmammary infections avoiding bacteriological analysis.
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Hilmi D, Parcina M, Bode K, Ostrop J, Schuett S, Heeg K, Ziebuhr W, Sommerburg O, Bekeredjian-Ding I. Functional variation reflects intra-strain diversity of Staphylococcus aureus small colony variants in the host–pathogen interaction. Int J Med Microbiol 2013; 303:61-9. [DOI: 10.1016/j.ijmm.2012.12.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2012] [Revised: 11/26/2012] [Accepted: 12/02/2012] [Indexed: 10/27/2022] Open
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Chen YW, Wang H, Hupert M, Soper SA. Identification of methicillin-resistant Staphylococcus aureus using an integrated and modular microfluidic system. Analyst 2013; 138:1075-83. [DOI: 10.1039/c2an36430a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Coombs GW, Goering RV, Chua KYL, Monecke S, Howden BP, Stinear TP, Ehricht R, O'Brien FG, Christiansen KJ. The molecular epidemiology of the highly virulent ST93 Australian community Staphylococcus aureus strain. PLoS One 2012; 7:e43037. [PMID: 22900085 PMCID: PMC3416834 DOI: 10.1371/journal.pone.0043037] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Accepted: 07/16/2012] [Indexed: 12/25/2022] Open
Abstract
In Australia the PVL-positive ST93-IV [2B], colloquially known as "Queensland CA-MRSA" has become the dominant CA-MRSA clone. First described in the early 2000s, ST93-IV [2B] is associated with skin and severe invasive infections including necrotizing pneumonia. A singleton by multilocus sequence typing (MLST) eBURST analysis ST93 is distinct from other S. aureus clones. To determine if the increased prevalence of ST93-IV [2B] is due to the widespread transmission of a single strain of ST93-IV [2B] the genetic relatedness of 58 S. aureus ST93 isolated throughout Australia over an extended period were studied in detail using a variety of molecular methods including pulsed-field gel electrophoresis, spa typing, MLST, microarray DNA, SCCmec typing and dru typing. Identification of the phage harbouring the lukS-PV/lukF-PV Panton Valentine leucocidin genes, detection of allelic variations in lukS-PV/lukF-PV, and quantification of LukF-PV expression was also performed. Although ST93-IV [2B] is known to have an apparent enhanced clinical virulence, the isolates harboured few known virulence determinants. All PVL-positive isolates carried the PVL-encoding phage ΦSa2USA and the lukS-PV/lukF-PV genes had the same R variant SNP profile. The isolates produced similar expression levels of LukF-PV. Although multiple rearrangements of the spa sequence have occurred, the core genome in ST93 is very stable. The emergence of ST93-MRSA is due to independent acquisitions of different dru-defined type IV and type V SCCmec elements in several spa-defined ST93-MSSA backgrounds. Rearrangement of the spa sequence in ST93-MRSA has subsequently occurred in some of these strains. Although multiple ST93-MRSA strains were characterised, little genetic diversity was identified for most isolates, with PVL-positive ST93-IVa [2B]-t202-dt10 predominant across Australia. Whether ST93-IVa [2B] t202-dt10 arose from one PVL-positive ST93-MSSA-t202, or by independent acquisitions of SCCmec-IVa [2B]-dt10 into multiple PVL-positive ST93-MSSA-t202 strains is not known.
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Affiliation(s)
- Geoffrey W Coombs
- Australian Collaborating Centre for Enterococcus and Sdtaphylococcus Species (ACCESS) Typing and Research, PathWest Laboratory Medicine-Western Australia, Royal Perth Hospital, Western Australia, Australia.
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Afshari A, Schrenzel J, Ieven M, Harbarth S. Bench-to-bedside review: Rapid molecular diagnostics for bloodstream infection--a new frontier? CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2012; 16:222. [PMID: 22647543 PMCID: PMC3580598 DOI: 10.1186/cc11202] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Among critically ill patients, the diagnosis of bloodstream infection poses a major challenge. Current standard bacterial identification based on blood culture platforms is intrinsically time-consuming and slow. The continuous evolvement of molecular techniques has the potential of providing a faster, more sensitive and direct identification of causative pathogens without prior need for cultivation. This may ultimately impact clinical decision-making and antimicrobial treatment. This review summarises the currently available technologies, their strengths and limitations and the obstacles that have to be overcome in order to develop a satisfactory bedside point-of-care diagnostic tool for detection of bloodstream infection.
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Wehrhahn MC, Robinson JO, Pascoe EM, Coombs GW, Pearson JC, O'Brien FG, Tan HL, New D, Salvaris P, Salvaris R, Murray RJ. Illness severity in community-onset invasive Staphylococcus aureus infection and the presence of virulence genes. J Infect Dis 2012; 205:1840-8. [PMID: 22492857 DOI: 10.1093/infdis/jis279] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND It is uncertain whether particular clones causing invasive community-onset methicillin-resistant and methicillin-sensitive Staphylococcus aureus (cMRSA/cMSSA) infection differ in virulence. METHODS Invasive cMRSA and cMSSA cases were prospectively identified. Principal component analysis was used to derive an illness severity score (ISS) from clinical data, including 30-day mortality, requirement for intensive hospital support, the presence of bloodstream infection, and hospital length of stay. The mean ISS for each S. aureus clone (based on MLST) was compared with its DNA microarray-based genotype. RESULTS Fifty-seven cMRSA and 50 cMSSA infections were analyzed. Ten clones caused 82 (77%) of these infections and had an ISS calculated. The enterotoxin gene cluster (egc) and the collagen adhesin (cna) gene were found in 4 of the 5 highest-ranked clones (ST47-MSSA, ST30-MRSA-IV[2B], ST45-MSSA, and ST22-MRSA-IV[2B]) compared with none and 1 of the lowest 5 ranked clones, respectively. cMSSA clones caused more severe infection than cMRSA clones. The lukF/lukS Panton-Valentine leukocidin (PVL) genes did not directly correlate with the ISS, being present in the second, fourth, and 10th most virulent clones. CONCLUSIONS The clinical severity of invasive cMRSA and cMSSA infection is likely to be attributable to the isolates' entire genotype rather than a single putative virulence determinant such as PVL.
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Affiliation(s)
- Michael C Wehrhahn
- Department of Microbiology and Infectious Diseases, Royal Perth Hospital and PathWest Laboratory Medicine, WA. mcwehrhahn@hotmail
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Formal infectious diseases consultation is associated with decreased mortality in Staphylococcus aureus bacteraemia. Eur J Clin Microbiol Infect Dis 2012; 31:2421-8. [PMID: 22382823 DOI: 10.1007/s10096-012-1585-y] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2011] [Accepted: 02/07/2012] [Indexed: 10/28/2022]
Abstract
To determine the impact of infectious diseases consultation (IDC) in Staphylococcus aureus bacteraemia. All MRSA bacteraemia and a random subset of MSSA bacteraemia were retrospectively analysed. Out of 599 SAB episodes, 162 (27%) were followed by an IDC. Patients with IDC were younger and more frequently intravenous drug users, but fewer resided in a long-term care facility or were indigenous. Hospital length of stay was longer (29.5 vs 17 days, p < 0.001), and endocarditis (19.1% vs 7.3%, p < 0.001) and metastatic seeding (22.2% vs 10.1%, p < 0.001) were more frequent in the IDC group; however, SAPS II scores were lower in the IDC group (27 vs 37, p < 0.001). ICU admission rates in the two groups were similar. The isolate tested susceptible to empirical therapy more frequently in the IDC group (88.9% vs 78.0%, p = 0.003). Seven-day (3.1 vs 16.5%), 30-day (8.0% vs 27.0%) and 1-year mortality (22.2% vs 44.9%) were all lower in the IDC group (all p < 0.001). Multivariate analysis showed that effective initial therapy was the only variable associated with the protective effect of IDC. In patients with SAB, all-cause mortality was significantly lower in patients who had an IDC, because of the higher proportion of patients receiving effective initial antibiotics.
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Pilla R, Castiglioni V, Gelain ME, Scanziani E, Lorenzi V, Anjum M, Piccinini R. Long-term study of MRSA ST1, t127 mastitis in a dairy cow. Vet Rec 2012; 170:312. [PMID: 22383329 DOI: 10.1136/vr.100510] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- R Pilla
- Department of Veterinary Pathology, Hygiene and Public Health, Università degli Studi di Milano, Via Celoria 10, 20133 Milano, Italy
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Yadav MK, Kwon SK, Huh HJ, Chae SW, Song JJ. Detection of methicillin-resistant Staphylococcus aureus (MRSA) from nasal samples by multiplex real-time PCR based on dual priming AT-rich primers. Folia Microbiol (Praha) 2011; 57:37-45. [PMID: 22187362 DOI: 10.1007/s12223-011-0085-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 10/25/2011] [Indexed: 10/14/2022]
Abstract
In this study, we reported on the design of a multiplex real-time PCR assay based on SYBR Green I, incorporating dual priming adenine-thymine (AT)-rich primers for direct detection of MRSA from nasal samples. The multiplex real-time polymerase chain reaction (RT-PCR) assay reported in this study is based on SYBR Green I with incorporation of six dual priming AT-rich primers designed from the SCCmec/orf junction. A string (4-6 bp) of low-melting bases, such as adenine and thymine, was incorporated into the primers, which virtually divided a single primer in two functional regions, thus decreasing non-specific PCR products. The analytical sensitivity and specificity of the RT-PCR assay was determined with genomic DNA of reference strains (MRSA, MSSA, and MRCoNS). RT-PCR assay was performed for analysis of 72 nasal swab specimens, and the results were confirmed by use of a culture method. Furthermore, the results of RT-PCR were compared with LightCycler MRSA advance test. The multiplex RT-PCR assay reproducibly detected a minimum of 1 pg genomic DNA (31.5 copy of genome) of MRSA reference strains and clinical isolates, with a specific melting peak at 83.5 ± 1.5°C, and neither fluorescence nor a melting peak was detected in non-target isolates. The concordance rate between RT-PCR assay and culture method was 87.5% with Cohen's kappa value (κ) 0.75, which showed good agreement between the two assays. The sensitivity, specificity, positive predictive value, and negative predictive value of the assay were 93.5%, 82.9%, 80.5%, and 94.4%, respectively. In a comparative study for the detection of 72 nasal samples, the sensitivity, specificity, positive predictive value, and negative predictive value of the multiplex RT-PCR assay with respect to LightCycler MRSA advance test was 84.2%, 88.2%, 89%, and, 83.3%, respectively. The results of RT-PCR assay demonstrated high specificity (88.2%) and positive predictive value (89%) for the direct detection of MRSA from nasal samples.
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Affiliation(s)
- M K Yadav
- Department of Otorhinolaryngology-Head and Neck Surgery, Dongguk University Ilsan Hospital, Goyang, Gyeonggi, South Korea
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Klein S, Zimmermann S, Köhler C, Mischnik A, Alle W, Bode KA. Integration of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry in blood culture diagnostics: a fast and effective approach. J Med Microbiol 2011; 61:323-331. [PMID: 22074848 DOI: 10.1099/jmm.0.035550-0] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Sepsis is a major cause of mortality in hospitalized patients worldwide, with lethality rates ranging from 30 to 70 %. Sepsis is caused by a variety of different pathogens, and rapid diagnosis is of outstanding importance, as early and adequate antimicrobial therapy correlates with positive clinical outcome. In recent years, matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS) fingerprinting has become a powerful tool in microbiological diagnostics. The direct identification of micro-organisms in a positive blood culture by MALDI-TOF MS can shorten the diagnostic procedure significantly. Therefore, the aim of the present study was to evaluate whether identification rates could be improved by using the new Sepsityper kit from Bruker Daltonics for direct isolation and identification of bacteria from positive blood cultures by MALDI-TOF MS compared with the use of conventional separator gel columns, and to integrate the MALDI-TOF MS-based identification method into the routine course of blood culture diagnostics in the setting of a microbiological laboratory at a university hospital in Germany. The identification of Gram-negative bacteria by MALDI-TOF MS was significantly better using the Sepsityper kit compared with a separator gel tube-based method (99 and 68 % correct identification, respectively). For Gram-positive bacteria, only 73 % were correctly identified by MALDI-TOF with the Sepsityper kit and 59 % with the separator gel tube assay. A major problem of both methods was the poor identification of Gram-positive grape-like clustered cocci. As differentiation of Staphylococcus aureus from coagulase-negative staphylococci is of clinical importance, a PCR was additionally established that was capable of identifying S. aureus directly from positive blood cultures, thus closing this diagnostic gap. Another benefit of the PCR approach is the possibility of directly detecting the genes responsible for meticillin resistance in staphylococci and for vancomycin resistance in enterococci, which is of high importance for early adequate treatment. Both of the described methods were finally integrated into a protocol for fast and effective identification of bacteria from positive blood cultures.
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Affiliation(s)
- Sabrina Klein
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University of Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Stefan Zimmermann
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University of Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Christine Köhler
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University of Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Alexander Mischnik
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University of Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Werner Alle
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University of Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
| | - Konrad A Bode
- Department of Infectious Diseases, Medical Microbiology and Hygiene, University of Heidelberg, Im Neuenheimer Feld 324, 69120 Heidelberg, Germany
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Coombs GW, Monecke S, Pearson JC, Tan HL, Chew YK, Wilson L, Ehricht R, O'Brien FG, Christiansen KJ. Evolution and diversity of community-associated methicillin-resistant Staphylococcus aureus in a geographical region. BMC Microbiol 2011; 11:215. [PMID: 21955438 PMCID: PMC3197503 DOI: 10.1186/1471-2180-11-215] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 09/29/2011] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) was first reported in remote regions of Western Australia and is now the predominant MRSA isolated in the state. The objective of this study is to determine the genetic relatedness of Western Australian CA-MRSA clones within different multilocus sequence type (MLST) clonal clusters providing an insight into the frequency of S. aureus SCCmec acquisition within a region. RESULTS The CA-MRSA population in Western Australia is genetically diverse consisting of 83 unique pulsed-field gel electrophoresis strains from which 46 MLSTs have been characterised. Forty five of these sequence types are from 18 MLST clonal clusters and two singletons. While SCCmec IV and V are the predominant SCCmec elements, SCCmec VIII and several novel and composite SCCmec elements are present. The emergence of MRSA in diverse S. aureus clonal clusters suggests horizontal transmission of the SCCmec element has occurred on multiple occasions. Furthermore DNA microarray and spa typing suggests horizontal transfer of SCCmec elements has also occurred within the same CC. For many single and double locus variant CA-MRSA clones only a few isolates have been detected. CONCLUSIONS Although multiple CA-MRSA clones have evolved in the Western Australian community only three clones have successfully adapted to the Western Australian community environment. These data suggest the successful evolution of a CA-MRSA clone may not only depend on the mobility of the SCCmec element but also on other genetic determinants.
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Affiliation(s)
- Geoffrey W Coombs
- Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research. PathWest Laboratory Medicine - WA, Royal Perth Hospital, Wellington Street, Perth, Western Australia, 6000 Australia
- School of Biomedical Sciences. Curtin University of Technology, GPO Box U1987, Perth, Western Australia, 6000 Australia
| | - Stefan Monecke
- Alere Technologies GmbH, Löbstedter Straße 103-105, D-07749 Jena, Germany
| | - Julie C Pearson
- Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research. PathWest Laboratory Medicine - WA, Royal Perth Hospital, Wellington Street, Perth, Western Australia, 6000 Australia
| | - Hui-leen Tan
- Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research. PathWest Laboratory Medicine - WA, Royal Perth Hospital, Wellington Street, Perth, Western Australia, 6000 Australia
| | - Yi-Kong Chew
- Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research. PathWest Laboratory Medicine - WA, Royal Perth Hospital, Wellington Street, Perth, Western Australia, 6000 Australia
| | - Lynne Wilson
- Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research. PathWest Laboratory Medicine - WA, Royal Perth Hospital, Wellington Street, Perth, Western Australia, 6000 Australia
| | - Ralf Ehricht
- Alere Technologies GmbH, Löbstedter Straße 103-105, D-07749 Jena, Germany
| | - Frances G O'Brien
- School of Biomedical Sciences. Curtin University of Technology, GPO Box U1987, Perth, Western Australia, 6000 Australia
| | - Keryn J Christiansen
- Australian Collaborating Centre for Enterococcus and Staphylococcus Species (ACCESS) Typing and Research. PathWest Laboratory Medicine - WA, Royal Perth Hospital, Wellington Street, Perth, Western Australia, 6000 Australia
- School of Biomedical Sciences. Curtin University of Technology, GPO Box U1987, Perth, Western Australia, 6000 Australia
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Verwer PEB, Robinson JO, Coombs GW, Wijesuriya T, Murray RJ, Verbrugh HA, Riley T, Nouwen JL, Christiansen KJ. Prevalence of nasal methicillin-resistant Staphylococcus aureus colonization in healthcare workers in a Western Australian acute care hospital. Eur J Clin Microbiol Infect Dis 2011; 31:1067-72. [PMID: 21909648 DOI: 10.1007/s10096-011-1408-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2011] [Accepted: 08/25/2011] [Indexed: 11/26/2022]
Abstract
Due to a longstanding comprehensive "search and destroy policy", methicillin-resistant Staphylococcus aureus (MRSA) is not endemic in Western Australian (WA) acute care hospitals. As the prevalence of MRSA in the community has increased, healthcare workers (HCW) are at risk of importing MRSA into hospitals. We aimed to determine the prevalence of and risk factors for nasal MRSA colonization in our HCW population. A period prevalence study was conducted at an 850-bed tertiary hospital. Basic demographics and a nasal swab were obtained. A total of 1,542 HCWs employed in our centre were screened for MRSA, of whom 3.4% (n = 52) were colonized. MRSA colonization was more common in patient care assistants (6.8%) and nurses (5.2%) than in allied health professionals (1.7%) and doctors (0.7%) (p < 0.01). Working in "high-risk" wards that cared for MRSA colonized/infected patients was the strongest risk factor for HCW MRSA colonization (p < 0.001). ST1-IV and ST78-IV (the most common community clones in the region) were the most frequently identified clones. In conclusion, MRSA colonization of HCWs occurs primarily in HCWs caring for patients colonized or infected with MRSA. Surveillance screening of HCWs should be regularly performed on wards with patients with high MRSA colonization prevalence to prevent further spread in the hospital.
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Affiliation(s)
- P E B Verwer
- Department of Medical Microbiology & Infectious Diseases, Erasmus Medical Centre, Rotterdam, The Netherlands
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47
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Amir LH, Cullinane M, Garland SM, Tabrizi SN, Donath SM, Bennett CM, Cooklin AR, Fisher JRW, Payne MS. The role of micro-organisms (Staphylococcus aureus and Candida albicans) in the pathogenesis of breast pain and infection in lactating women: study protocol. BMC Pregnancy Childbirth 2011; 11:54. [PMID: 21777483 PMCID: PMC3151214 DOI: 10.1186/1471-2393-11-54] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Accepted: 07/22/2011] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND The CASTLE (Candida and Staphylococcus Transmission: Longitudinal Evaluation) study will investigate the micro-organisms involved in the development of mastitis and "breast thrush" among breastfeeding women. To date, the organism(s) associated with the development of breast thrush have not been identified. The CASTLE study will also investigate the impact of physical health problems and breastfeeding problems on maternal psychological health in the early postpartum period. METHODS/DESIGN The CASTLE study is a longitudinal descriptive study designed to investigate the role of Staphylococcus spp (species) and Candida spp in breast pain and infection among lactating women, and to describe the transmission dynamics of S. aureus and Candida spp between mother and infant. The relationship between breastfeeding and postpartum health problems as well as maternal psychological well-being is also being investigated. A prospective cohort of four hundred nulliparous women who are at least thirty six weeks gestation pregnant are being recruited from two hospitals in Melbourne, Australia (November 2009 to June 2011). At recruitment, nasal, nipple (both breasts) and vaginal swabs are taken and participants complete a questionnaire asking about previous known staphylococcal and candidal infections. Following the birth, participants are followed-up six times: in hospital and then at home weekly until four weeks postpartum. Participants complete a questionnaire at each time points to collect information about breastfeeding problems and postpartum health problems. Nasal and nipple swabs and breast milk samples are collected from the mother. Oral and nasal swabs are collected from the baby. A telephone interview is conducted at eight weeks postpartum to collect information about postpartum health problems and breastfeeding problems, such as mastitis and nipple and breast pain. DISCUSSION This study is the first longitudinal study of the role of both staphylococcal and candidal colonisation in breast infections and will help to resolve the current controversy about which is the primary organism in the condition known as breast thrush. This study will also document transmission dynamics of S. aureus and Candida spp between mother and infant. In addition, CASTLE will investigate the impact of common maternal physical health symptoms and the effect of breastfeeding problems on maternal psychological well-being.
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Affiliation(s)
- Lisa H Amir
- Mother & Child Health Research, La Trobe University, Melbourne, VIC 3000, Australia
| | - Meabh Cullinane
- Mother & Child Health Research, La Trobe University, Melbourne, VIC 3000, Australia
| | - Suzanne M Garland
- Women's Centre for Infectious Diseases, Bio 21 Institute, Parkville, VIC 3052, Australia
- University of Melbourne Department of Obstetrics and Gynaecology, The Royal Women's Hospital, Parkville, VIC 3052, Australia
- Murdoch Childrens Research Institute, The Royal Children's Hospital, Parkville, VIC 3052, Australia
| | - Sepehr N Tabrizi
- Women's Centre for Infectious Diseases, Bio 21 Institute, Parkville, VIC 3052, Australia
- University of Melbourne Department of Obstetrics and Gynaecology, The Royal Women's Hospital, Parkville, VIC 3052, Australia
- Murdoch Childrens Research Institute, The Royal Children's Hospital, Parkville, VIC 3052, Australia
| | - Susan M Donath
- Murdoch Childrens Research Institute, The Royal Children's Hospital, Parkville, VIC 3052, Australia
- University of Melbourne Department of Paediatrics, The Royal Children's Hospital, Parkville, VIC 3052, Australia
| | | | | | - Jane RW Fisher
- Jean Hailes Research Unit, Monash University, Clayton, VIC 3168, Australia
- Centre for Women's Health, Gender and Society, University of Melbourne, Carlton, VIC 3053, Australia
| | - Matthew S Payne
- Mother & Child Health Research, La Trobe University, Melbourne, VIC 3000, Australia
- Women's Centre for Infectious Diseases, Bio 21 Institute, Parkville, VIC 3052, Australia
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Ozen NS, Ogunc D, Mutlu D, Ongut G, Baysan BO, Gunseren F. Comparison of four methods for rapid identification of Staphylococcus aureus directly from BACTEC 9240 blood culture system. Indian J Med Microbiol 2011; 29:42-6. [PMID: 21304194 DOI: 10.4103/0255-0857.76523] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
PURPOSE Differentiation of Staphylococcus aureus (S. aureus) from coagulase-negative staphylococci is very important in blood stream infections. Identification of S. aureus and coagulase-negative staphylococci (CoNS) from blood cultures takes generally 18-24 h after positive signaling on continuously monitored automated blood culture system. In this study, we evaluated the performance of tube coagulase test (TCT), slide agglutination test (Dry Spot Staphytect Plus), conventional polymerase chain reaction (PCR) and LightCycler Staphylococcus MGrade kit directly from blood culture bottles to achieve rapid identification of S. aureus by using the BACTEC 9240 blood culture system. MATERIALS AND METHODS A total of 129 BACTEC 9240 bottles growing gram-positive cocci suggesting Staphylococci were tested directly from blood culture broths (BCBs) with TCT, Dry Spot Staphytect Plus, conventional PCR and LightCycler Staphylococcus MGrade kit for rapid identification of S. aureus. RESULTS The sensitivities of the tests were 99, 68, 99 and 100%, respectively. CONCLUSION Our results suggested that 2 h TCT was found to be simple and inexpensive method for the rapid identification of S. aureus directly from positive blood cultures.
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Affiliation(s)
- N S Ozen
- Department of Clinical Microbiology, Akdeniz University Medical Faculty, Antalya, Turkey
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Melendez JH, Frankel YM, An AT, Williams L, Price LB, Wang NY, Lazarus GS, Zenilman JM. Real-time PCR assays compared to culture-based approaches for identification of aerobic bacteria in chronic wounds. Clin Microbiol Infect 2011; 16:1762-9. [PMID: 21077984 DOI: 10.1111/j.1469-0691.2010.03158.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Chronic wounds cause substantial morbidity and disability. Infection in chronic wounds is clinically defined by routine culture methods that can take several days to obtain a final result, and may not fully describe the community of organisms or biome within these wounds. Molecular diagnostic approaches offer promise for a more rapid and complete assessment. We report the development of a suite of real-time PCR assays for rapid identification of bacteria directly from tissue samples. The panel of assays targets 14 common, clinically relevant, aerobic pathogens and demonstrates a high degree of sensitivity and specificity using a panel of organisms commonly associated with chronic wound infection. Thirty-nine tissue samples from 29 chronic wounds were evaluated and the results compared with those obtained by culture. As revealed by culture and PCR, the most common organisms were methicillin-resistant Staphylococcus aureus (MRSA) followed by Streptococcus agalactiae (Group B streptococcus) and Pseudomonas aeruginosa. The sensitivities of the PCR assays were 100% and 90% when quantitative and qualitative culture results were used as the reference standard, respectively. The assays allowed the identification of bacterial DNA from ten additional organisms that were not revealed by quantitative or qualitative cultures. Under optimal conditions, the turnaround time for PCR results is as short as 4-6 h. Real-time PCR is a rapid and inexpensive approach that can be easily introduced into clinical practice for detection of organisms directly from tissue samples. Characterization of the anaerobic microflora by real-time PCR of chronic wounds is warranted.
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Affiliation(s)
- J H Melendez
- Infectious Diseases, Johns Hopkins Medical Institutions, Johns Hopkins Wound Center at Bayview, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
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Cutaneous diphtheria in the urban poor population of Vancouver, British Columbia, Canada: a 10-year review. J Clin Microbiol 2011; 49:2664-6. [PMID: 21525220 DOI: 10.1128/jcm.00362-11] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Between 1998 and 2007, records from 33 patients with cutaneous diphtheria from Vancouver's inner city were reviewed. Cases were associated with injection drug use and poverty. Coinfections with Staphylococcus aureus, Streptococcus pyogenes, and Arcanobacterium haemolyticum occurred. Corynebacterium diphtheriae is endemic in Vancouver's urban core, with strains of multilocus sequence type (MLST) 76 predominating.
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