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Sagiraju M, Prasad R, Gopi A. Diabetes and MRSA Infections: A comparative analysis in an Indian tertiary healthcare setting. Infect Prev Pract 2024; 6:100372. [PMID: 38882195 PMCID: PMC11176644 DOI: 10.1016/j.infpip.2024.100372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Accepted: 05/13/2024] [Indexed: 06/18/2024] Open
Affiliation(s)
- M Sagiraju
- Kempegowda Institute of Medical Sciences, Bangalore, India
| | - R Prasad
- Centre for Brain Research, Indian Institute of Science, Bangalore, India
| | - A Gopi
- Kempegowda Institute of Medical Sciences, Bangalore, India
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Wang X, Meng T, Dai Y, Ou HY, Wang M, Tang B, Sun J, Cheng D, Pan T, Tan R, Qu H. High prevalence of polymyxin-heteroresistant carbapenem-resistant Klebsiella pneumoniae and its within-host evolution to resistance among critically ill scenarios. Infection 2024:10.1007/s15010-024-02365-z. [PMID: 39143437 DOI: 10.1007/s15010-024-02365-z] [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: 06/06/2024] [Accepted: 07/29/2024] [Indexed: 08/16/2024]
Abstract
PURPOSE We aimed to explore the prevalence and within-host evolution of resistance in polymyxin-heteroresistant carbapenem-resistant Klebsiella pneumoniae (PHR-CRKP) in critically ill patients. METHODS We performed an epidemiological analysis of consecutive patients with PHR-CRKP from clinical cases. Our study investigated the within-host resistance evolution and its clinical significance during polymyxin exposure. Furthermore, we explored the mechanisms underlying the dynamic evolution of polymyxin resistance at both subpopulation and genetic levels, involved population analysis profile test, time-killing assays, competition experiments, and sanger sequencing. Additionally, comparative genomic analysis was performed on 713 carbapenemase-producing K. pneumoniae strains. RESULTS We enrolled 109 consecutive patients, and PHR-CRKP was found in 69.7% of patients without previous polymyxin exposure. 38.1% of PHR-CRKP isolates exhibited polymyxin resistance and led to therapeutic failure in critically ill scenarios. An increased frequency of resistant subpopulations was detected during PHR-CRKP evolution, with rapid regrowth of resistant subpopulations under high polymyxin concentrations, and a fitness cost in an antibiotic-free environment. Mechanistic analysis revealed that diverse mgrB insertions and pmrB hypermutations contributed to the dynamic changes in polymyxin susceptibility in dominant resistant subpopulations during PHR evolution, which were validated by comparative genomic analysis. Several deleterious mutations (e.g. pmrBLeu82Arg, pmrBSer85Arg) were firstly detected during PHR-CRKP evolution. Indeed, specific sequence types of K. pneumoniae demonstrated unique deletions and deleterious mutations. CONCLUSIONS Our study emphasizes the high prevalence of pre-existing heteroresistance in CRKP, which can lead to polymyxin resistance and fatal outcomes. Hence, it is essential to continuously monitor and observe the treatment response to polymyxins in appropriate critically ill scenarios.
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Affiliation(s)
- Xiaoli Wang
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin ER Road, Shanghai, 200025, China
| | - Tianjiao Meng
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin ER Road, Shanghai, 200025, China
| | - Yunqi Dai
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin ER Road, Shanghai, 200025, China
| | - Hong-Yu Ou
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Meng Wang
- State Key Laboratory of Microbial Metabolism, Joint International Laboratory on Metabolic & Developmental Sciences, School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, 200030, China
| | - Bin Tang
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin ER Road, Shanghai, 200025, China
| | - Jingyong Sun
- Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, 200025, China
| | - Decui Cheng
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin ER Road, Shanghai, 200025, China
| | - Tingting Pan
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin ER Road, Shanghai, 200025, China.
| | - Ruoming Tan
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin ER Road, Shanghai, 200025, China.
| | - Hongping Qu
- Department of Critical Care Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, No. 197, Ruijin ER Road, Shanghai, 200025, China.
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Khapuinamai A, Dave VP, Tyagi M, Joseph J. Effect of Age on the Etiology and Antibiotic Susceptibility Pattern of Infectious Endophthalmitis. Ocul Immunol Inflamm 2024; 32:838-842. [PMID: 37922464 DOI: 10.1080/09273948.2023.2274495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 10/17/2023] [Accepted: 10/18/2023] [Indexed: 11/05/2023]
Abstract
PURPOSE To review the etiology and antibiotic susceptibility patterns of infectious endophthalmitis over 11 years in different age groups. METHODS Microbiology records of culture-positive endophthalmitis cases from January 2011 and December 2021 were reviewed for the age groups 0-30, 31-60, and >60 years. Additionally, data was also analysed for trends in antibiotic susceptibility between different age groups. RESULTS A total of 5590 patients were clinically diagnosed with endophthalmitis. Of these, 1316 (23.5%) patients were culture positive comprising of 1097 bacteria (83.3%) and 219 fungal (16.6%). Gram-positive bacteria predominated the culture-proven bacterial endophthalmitis group with 709 cases (62.6%). Streptococcus pneumoniae (9.3%) was the most prevalent organism in the age group between 0 and 30 years, while Staphylococcus epidermidis (6%) was the most prevalent organism in the age group of 31-60 years. In comparison, Pseudomonas aeruginosa (4.1%) was the most abundant organism in the age group >60 years. Interestingly, Aspergillus flavus (13.24%) was the predominant fungal pathogen in all age groups. There was an increasing trend in antibiotic resistance from younger to older age groups and this pattern was observed for almost all drugs tested except vancomycin and amikacin. CONCLUSION While infection can occur at any age, the etiology also seems to vary. This study helps us understand the demography of endophthalmitis along with choice of empirical antibiotics that would influence treatment outcomes. Although vancomycin currently holds good for the treatment for gram-positive infections, gram-negative infections calls for an immediate need for newer drugs or advanced treatment options.
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Affiliation(s)
- Agimanailiu Khapuinamai
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Hyderabad, India
| | - Vivek Pravin Dave
- Anant Bajaj Retina Institute, LV Prasad Eye Institute, Hyderabad, India
| | - Mudit Tyagi
- Anant Bajaj Retina Institute, LV Prasad Eye Institute, Hyderabad, India
| | - Joveeta Joseph
- Jhaveri Microbiology Centre, Brien Holden Eye Research Centre, L. V. Prasad Eye Institute, Hyderabad, India
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Das AV, Dave VP, Tyagi M, Joseph J. Microbiological Landscape and Epidemiology of Endophthalmitis in Children and Adolescents in a Multi-Tier Ophthalmology Network in India: An Electronic Medical Record-Driven Analytics Report. Ocul Immunol Inflamm 2024; 32:843-849. [PMID: 38241631 DOI: 10.1080/09273948.2023.2298932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2022] [Revised: 12/13/2023] [Accepted: 12/19/2023] [Indexed: 01/21/2024]
Abstract
PURPOSE To study the epidemiology and microbiological landscape in patients (≤21 yrs) diagnosed with endophthalmitis across a multi-tier ophthalmology network in India. METHODS This cross-sectional hospital-based study included 1,041 patients (≤21 yrs) diagnosed with endophthalmitis, between April 2012 and May 2022. The data were collected using an electronic medical record system. RESULTS Bacteria (24%) was the most common etiology followed by fungus (2%). The majority of the patients were male (66%) with a mean age of 8.37 ± 5.99 years. The most common age group was middle childhood (6-11 years) with 365 (35.06%) patients. The patients were more commonly from the lower socio-economic status (60.81%) and urban geography (49%). The common cause of endophthalmitis was trauma (59.33%) and amongst the 279 culture positive eyes, the predominant bacteria isolated was Streptococcus pneumoniae followed by Bacillus species and fungus included predominantly Aspergillus and Candida species. The most common surgical intervention performed was intraocular antibiotics (74%) followed by pars plana vitrectomy (52%). CONCLUSION The most common etiology of endophthalmitis in children is bacterial and traumatic in nature and presented from the lower socio-economic status. A half of the eyes warranted a vitreo-retinal surgical intervention. .
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Affiliation(s)
- Anthony Vipin Das
- Department of eyeSmart EMR & AEye, LV Prasad Eye Institute, Hyderabad, India
- Indian Health Outcomes, Public Health and Economics Research Centre, Hyderabad, India
| | - Vivek Pravin Dave
- Smt. Kanuri Santhamma Center for Vitreoretinal Diseases, LV Prasad Eye Institute, Hyderabad, India
| | - Mudit Tyagi
- Smt. Kanuri Santhamma Center for Vitreoretinal Diseases, LV Prasad Eye Institute, Hyderabad, India
| | - Joveeta Joseph
- Jhaveri Microbiology Centre, LV Prasad Eye Institute, Hyderabad, India
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Malepati N, Mitra S, Chandran K, Shanbhag SS. Secondary bacterial corneal infection caused by Myroides species in primary fungal keratitis. BMJ Case Rep 2024; 17:e258474. [PMID: 38719269 PMCID: PMC11085784 DOI: 10.1136/bcr-2023-258474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/13/2024] Open
Abstract
A middle-aged male patient presented with a central corneal perforation in a deep stromal infiltrate in his left eye. An emergency therapeutic penetrating keratoplasty was performed. Microbiological evaluation of the corneal scraping specimen revealed septate fungal filaments on stains. However, culture reports after 24 hours from the scraping sample and the excised half corneal button showed growth of gram-negative bacilli. This pathogen was identified as an aerobic, non-fermentative, gram-negative, bacillus by conventional microbiology and confirmed as Myroides species by the VITEK 2 Compact system (bioMérieux, Marcy l'Etoile, France). Susceptibility to chloramphenicol was noted based on which the patient was treated with topical chloramphenicol 0.5%. No recurrence of the infection was noted. This is the first reported case of corneal infection with the Myroides species of bacteria which, heretofore, have been known to cause endocarditis and urinary tract infections.
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Affiliation(s)
- Nikhila Malepati
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Sanchita Mitra
- Jhaveri Microbiology Center, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Kavya Chandran
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
| | - Swapna S Shanbhag
- Shantilal Shanghvi Cornea Institute, LV Prasad Eye Institute, Hyderabad, Telangana, India
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Elmaghrabi MM, Alharbi NS, Alobaidi AS, Abdulmanea AA, Kadaikunnan S, Ramadan AA, Khaled JM. Iron-tannic acid nano-coating: A promising treatment approach for enhancing Lactococcus lactis antibiotic resistance. Saudi Pharm J 2024; 32:102052. [PMID: 38590610 PMCID: PMC10999874 DOI: 10.1016/j.jsps.2024.102052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 03/26/2024] [Indexed: 04/10/2024] Open
Abstract
The objective of this study was to explore a novel methodology for the synthesis of nanocoated probiotics following their collection and cultivation under optimized conditions, in light of their significant contribution to human health. Probiotics are instrumental in sustaining immune health by modulating the gastrointestinal microbiota and facilitating digestion. However, the equilibrium they maintain can be adversely affected by antibiotic treatments. It is critical to investigate the vulnerability of probiotics to antibiotics, considering the potential implications. This research aimed to assess whether nanoparticle coating could augment the probiotics' resistance to antibiotic influence. A strain of Lactococcus lactis (L. lactis) was isolated, cultured, and comprehensively characterized utilizing state-of-the-art methodologies, including the VITEK® 2 compact system, VITEK® MS, and 16S rRNA gene sequencing. The nanoparticle coating was performed using iron (III) chloride hexahydrate and tannic acid, followed by an evaluation of the probiotics' resistance to a range of antibiotics. The analysis through scanning electron microscopy (SEM) and atomic force microscopy (AFM) demonstrated a partial nanoparticle coating of the probiotics, which was further supported by UV/Vis spectroscopy findings, suggesting enhanced resistance to standard antibiotics. The results revealed that this strain possesses a unique protein profile and is genetically similar to strains identified in various other countries. Moreover, nano-encapsulation notably increased the strain's resistance to a spectrum of standard antibiotics, including Benzylpenicillin, Teicoplanin, Oxacillin, Vancomycin, Tetracycline, Rifampicin, Erythromycin, and Clindamycin. These findings imply that nanoparticle-coated probiotics may effectively counteract the detrimental effects of extended antibiotic therapy, thus preserving their viability and beneficial influence on gastrointestinal health.
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Affiliation(s)
- Marwa M. Elmaghrabi
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Naiyf S. Alharbi
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Ahmed S. Alobaidi
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Adel A. Abdulmanea
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Shine Kadaikunnan
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | | | - Jamal M. Khaled
- Department of Botany and Microbiology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
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K S, Nechikkadan S, Theresa M, Krishnankutty RE. ZnO nanoparticles induced biofilm formation in Klebsiella pneumoniae and Staphylococcus aureus at sub-inhibitory concentrations. Folia Microbiol (Praha) 2024:10.1007/s12223-024-01158-z. [PMID: 38564153 DOI: 10.1007/s12223-024-01158-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 03/18/2024] [Indexed: 04/04/2024]
Abstract
Biofilm formation by the pathogenic bacteria generates a serious threat to the public health as it can increase the virulence potential, resistance to drugs, and escape from the host immune response mechanisms. Among the environmental factors that influence the biofilm formation, there are only limited reports available on the role of antimicrobial agents. During the antimicrobial drug administration or application for any purpose, the microbial population can expect to get exposed to the sub-minimum inhibitory concentration (sub-MIC) of the drug which will have an unprecedented impact on microbial responses. Hence, the study has been conducted to investigate the effects of sub-MIC levels of zinc oxide nanoparticles (ZnO NPs) on the biofilm formation of Klebsiella pneumoniae and Staphylococcus aureus. Here, the selected bacteria were primarily screened for the biofilm formation by using the Congo red agar method, and their susceptibility to ZnO NPs was also evaluated. Quantitative difference in biofilm formation by the selected organisms in the presence of ZnO NPs at the sub-MIC level was further carried out by using the microtiter plate-crystal violet assay. Further, the samples were subjected to atomic force microscopy (AFM) analysis to evaluate the properties and pattern of the biofilm modulated under the experimental conditions used. From these, the organisms treated with sub-MIC levels of ZnO NPs were found to have enhanced biofilm formation when compared with the untreated sample. Also, no microbial growth could be observed for the samples treated with the minimum inhibitory concentration (MIC) of ZnO NPs. The results observed in the study provide key insights into the impact of nanomaterials on clinically important microorganisms which demands critical thinking on the antimicrobial use of nanomaterials.
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Affiliation(s)
- Sreekanth K
- School of Biosciences, Mahatma Gandhi University, Priyadarshini Hills (P.O), Kottayam, Kerala, Pin: 686, 560, India
| | - Safa Nechikkadan
- School of Biosciences, Mahatma Gandhi University, Priyadarshini Hills (P.O), Kottayam, Kerala, Pin: 686, 560, India
| | - Mary Theresa
- School of Biosciences, Mahatma Gandhi University, Priyadarshini Hills (P.O), Kottayam, Kerala, Pin: 686, 560, India
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Hellebuyck T, Kotyk M, Solanes Vilanova F, Čepička I. The association of bacterial agents and flagellated protozoans in the etiopathogenesis of subspectacular abscesses in snakes. Vet Ophthalmol 2024. [PMID: 38491730 DOI: 10.1111/vop.13210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/14/2024] [Accepted: 03/06/2024] [Indexed: 03/18/2024]
Abstract
OBJECTIVES To describe the etiology, clinical pathology, and treatment of subspectacular abscesses (SAs) in 16 snakes. ANIMALS STUDIED Sixteen snakes from private captive collections that were presented at a veterinary teaching hospital and diagnosed with SAs. PROCEDURES Exudate was collected from SAs via percutaneous aspiration or by performing a partial spectaculectomy and submitted to direct light microscopic examination and/or microbiological examination. RESULTS Bacterial isolates were cultured from exudate samples in 12 out of 16 snakes and comprised Pseudomonas aeruginosa isolates that showed identical antimicrobial susceptibility patterns in seven cases. Direct light microscopic examination demonstrated the presence of flagellated protozoa in the exudate in 10 out of 16 snakes and in all of these snakes, concurrent oropharyngeal flagellated protozoan infection could be demonstrated. Combined flagellated protozoan and bacterial SA infection was demonstrated in six snakes. Comparison of small subunit ribosomal RNA gene sequences of flagellated protozoans that were detected in the exudate of SAs from four snakes revealed they represented the parabasalians Monocercomonas colubrorum and Hypotrichomonas acosta in one and three cases, respectively. In all snakes, successful treatment of the SAs was achieved following surgical debridement of the subspectacular space combined with antimicrobial treatment. CONCLUSION Bacteria as well as flagellates are considered to reach the subspectacular space through ascending infection from the oral cavity via the lacrimal duct. Although opportunistic bacterial infection presumably constitutes the predominant cause of SAs in snakes, the role of flagellate infection in the pathogenesis of this disorder should be further elucidated.
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Affiliation(s)
- Tom Hellebuyck
- Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Michael Kotyk
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Ferran Solanes Vilanova
- Department of Pathobiology, Pharmacology and Zoological Medicine, Faculty of Veterinary Medicine, Ghent University, Merelbeke, Belgium
| | - Ivan Čepička
- Department of Zoology, Faculty of Science, Charles University, Prague, Czech Republic
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Ring N, Low AS, Wee B, Paterson GK, Nuttall T, Gally D, Mellanby R, Fitzgerald JR. Rapid metagenomic sequencing for diagnosis and antimicrobial sensitivity prediction of canine bacterial infections. Microb Genom 2023; 9:mgen001066. [PMID: 37471128 PMCID: PMC10438823 DOI: 10.1099/mgen.0.001066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2023] [Accepted: 06/18/2023] [Indexed: 07/21/2023] Open
Abstract
Antimicrobial resistance is a major threat to human and animal health. There is an urgent need to ensure that antimicrobials are used appropriately to limit the emergence and impact of resistance. In the human and veterinary healthcare setting, traditional culture and antimicrobial sensitivity testing typically requires 48-72 h to identify appropriate antibiotics for treatment. In the meantime, broad-spectrum antimicrobials are often used, which may be ineffective or impact non-target commensal bacteria. Here, we present a rapid, culture-free, diagnostics pipeline, involving metagenomic nanopore sequencing directly from clinical urine and skin samples of dogs. We have planned this pipeline to be versatile and easily implementable in a clinical setting, with the potential for future adaptation to different sample types and animals. Using our approach, we can identify the bacterial pathogen present within 5 h, in some cases detecting species which are difficult to culture. For urine samples, we can predict antibiotic sensitivity with up to 95 % accuracy. Skin swabs usually have lower bacterial abundance and higher host DNA, confounding antibiotic sensitivity prediction; an additional host depletion step will likely be required during the processing of these, and other types of samples with high levels of host cell contamination. In summary, our pipeline represents an important step towards the design of individually tailored veterinary treatment plans on the same day as presentation, facilitating the effective use of antibiotics and promoting better antimicrobial stewardship.
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Affiliation(s)
- Natalie Ring
- The Roslin Institute, University of Edinburgh, Edinburgh, UK
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Alison S. Low
- The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Bryan Wee
- The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Gavin K. Paterson
- The Roslin Institute, University of Edinburgh, Edinburgh, UK
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - Tim Nuttall
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
| | - David Gally
- The Roslin Institute, University of Edinburgh, Edinburgh, UK
| | - Richard Mellanby
- Royal (Dick) School of Veterinary Studies, University of Edinburgh, Edinburgh, UK
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Alshraiedeh N, Atawneh F, Bani-Salameh R, Alsharedeh R, Al Tall Y, Alsaggar M. Identification and characterization of bacteria isolated from patients with cystic fibrosis in Jordan. Ann Med 2022; 54:2796-2804. [PMID: 36264155 PMCID: PMC9586617 DOI: 10.1080/07853890.2022.2131282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
BACKGROUND Notable emergence of multidrug-resistant bacteria has become increasingly problematic worldwide. Most patients with cystic fibrosis (CF) suffer from chronic persistent infections with frequent occurrence of acute exacerbations. Routine screening of bacterial strains, epidemiological characteristics, and resistance patterns are particularly useful for patient management and maintenance of infection control procedures. METHODS In this study, 43 pharyngeal samples were taken from patients with CF. Microbiological bacterial culture and identification, antimicrobial susceptibility testings, biofilm formation, including minimum biofilm eradication concentration (MBEC) and PCR for detecting resistance genes were performed. RESULTS All samples were positive for bacterial growth. The predominant species were Staphylococcus aureus (41.86%; n = 18) and Pseudomonas aeruginosa (39.53%; n = 17). 30% of isolated bacteria were multidrug-resistant, resisting high concentrations of tested antibiotics. Among the 42 biofilm-forming isolates, 23.8% (n = 10) were strong biofilm formers. The occurance of resistance genes varied with blaKPC detected in 71% (n = 17) of all Gram-negative isolates and mecA found in 61% (n = 11) of all S. aureus strains. CONCLUSIONS The majority of isolated bacteria were S. aureus and P. aeruginosa. The high frequency of antimicrobial resistance, the presence of resistance genes, and biofilm formation highlight the challenge in treatment and infection control measures in patients with CF.KEY MESSAGESStaphylococcus aureus and Pseudomonas aeruginosa are the most prevalent pathogens found in patients with CF in Jordan.Detection of antimicrobial resistance genes in patients with CF confirms that antimicrobial resistance patterns must always be monitored.Biofilm formation significantly increases the tolerance of bacteria to antimicrobial agents.
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Affiliation(s)
- Nid'a Alshraiedeh
- Department of Pharmaceutical Technology, Jordan University of Science and Technology, Irbid, Jordan
| | - Farah Atawneh
- Department of Medical Laboratory Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Rasha Bani-Salameh
- Department of Medical Laboratory Sciences, Jordan University of Science and Technology, Irbid, Jordan
| | - Rawan Alsharedeh
- Department of the Pharmaceutics and Pharmaceutical Technology, Yarmouk University, Irbid, Jordan
| | - Yara Al Tall
- Department of Pharmaceutical Technology, Jordan University of Science and Technology, Irbid, Jordan
| | - Mohammad Alsaggar
- Department of Pharmaceutical Technology, Jordan University of Science and Technology, Irbid, Jordan
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Presence of quorum sensing system, virulence genes, biofilm formation and relationship among them and class 1 integron in carbapenem-resistant clinical Pseudomonas aeruginosa isolates. Arch Microbiol 2022; 204:464. [PMID: 35802194 DOI: 10.1007/s00203-022-03061-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Revised: 05/16/2022] [Accepted: 06/07/2022] [Indexed: 11/02/2022]
Abstract
Carbapenems are the most effective agents for treating clinical P. aeruginosa (PsA) infections. During an infection, a quorum-sensing (QS) system and its regulating virulence genes have a great role. The aim of the study was to detect the presence of a las and rhl QS system and related virulence genes, biofilm formation and a class 1 (Cls1) integron. A total of 52 carbapenem-resistant PsA (CRPsA) isolates obtained from Kastamonu, Turkey was analyzed. For the isolation and identification of CRPsA isolates, a conventional culture method, an automated VITEK-2 compact system, and oprL gene-based molecular technique were applied. The two QS system genes were detected in 51 (98.1%), and co-existed of four two QS system genes (lasI/R and rhIl/R genes) were determined in 41 (78.8%) of the isolates. algD, lasB, toxA and aprA genes were detected in between 46.1 and 88.5%, and co-existence of four two QS system genes with four virulence genes were detected in 40.4% of the isolates. Biofilm formation using microtiter plate assay and slime production using Congo Red Agar and Cls1 integron were determined in 84.6%, 67.3% and 51.9% of the isolates, respectively. According to statistical analyses results, there was a significant positive correlation (p < .10) between the las and the rhl systems and a strongly and positive correlation (p < .01 or p < .05) between the rhl system-three virulence genes and slime production-and among some virulence genes. In conclusion, the CRPsA isolates tested in the study are highly virulent and QS systems have a significant role in pathogenesis.
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Singh NK, Sahu S, Priyadarshini SR, Behera HS. First reported case of corneal infection caused by Atopobium vaginae. BMJ Case Rep 2022; 15:e248988. [PMID: 35760507 PMCID: PMC9237891 DOI: 10.1136/bcr-2022-248988] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/16/2022] [Indexed: 11/04/2022] Open
Abstract
A man in his 20s, with irritation, pain and photophobia in the left eye, was clinically diagnosed with herpes simplex virus nummular keratitis at our institute and advised topical antivirals and corticosteroids, causing resolution of active infiltrates. The infection recurred after 7 months and the patient did not respond to the previous regimen, so corneal scraping was sent for microbiological evaluation. Gram-positive bacilli grew on culture, which were identified as Atopobium vaginae using VITEK 2 Compact system (bioMérieux, Marcy l'Etoile, France). Gatifloxacin eye drops were added based on antibiotic sensitivity patterns. Infiltrates resolved completely, leaving behind residual scars without any recurrences. This is the first reported case of corneal infection caused by A. vaginae, a bacterium known to reside in the urogenital tract. It caused secondary corneal infection in a case of recurrent herpes simplex keratitis. Species identification systems like VITEK 2 Compact can help identify such rare bacteria with great accuracy.
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Affiliation(s)
- Nimish Kumar Singh
- Cornea and Anterior Segment, LV Prasad Eye Institute Bhubaneswar Campus, Bhubaneswar, India
| | - Srikant Sahu
- Cornea and Anterior Segment, LV Prasad Eye Institute Bhubaneswar Campus, Bhubaneswar, India
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Tao Q, Wu Q, Zhang Z, Liu J, Tian C, Huang Z, Malakar PK, Pan Y, Zhao Y. Meta-Analysis for the Global Prevalence of Foodborne Pathogens Exhibiting Antibiotic Resistance and Biofilm Formation. Front Microbiol 2022; 13:906490. [PMID: 35774452 PMCID: PMC9239547 DOI: 10.3389/fmicb.2022.906490] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 04/27/2022] [Indexed: 11/30/2022] Open
Abstract
Antimicrobial-resistant (AMR) foodborne bacteria causing bacterial infections pose a serious threat to human health. In addition, the ability of some of these bacteria to form biofilms increases the threat level as treatment options may become compromised. The extent of antibiotic resistance and biofilm formation among foodborne pathogens remain uncertain globally due to the lack of systematic reviews. We performed a meta-analysis on the global prevalence of foodborne pathogens exhibiting antibiotic resistance and biofilm formation using the methodology of a Cochrane review by accessing data from the China National Knowledge Infrastructure (CNKI), PubMed, and Web of Science databases between 2010 and 2020. A random effects model of dichotomous variables consisting of antibiotic class, sample source, and foodborne pathogens was completed using data from 332 studies in 36 countries. The results indicated AMR foodborne pathogens has become a worrisome global issue. The prevalence of AMR foodborne pathogens in food samples was greater than 10% and these foodborne pathogens were most resistant to β-lactamase antibiotics with Bacillus cereus being most resistant (94%). The prevalence of AMR foodborne pathogens in human clinical specimens was greater than 19%, and the resistance of these pathogens to the antibiotic class used in this research was high. Independently, the overall biofilm formation rate of foodborne pathogenic bacteria was 90% (95% CI, 68%–96%) and a direct linear relationship between biofilm formation ability and antibiotic resistance was not established. Future investigations should document both AMR and biofilm formation of the foodborne pathogen isolated in samples. The additional information could lead to alternative strategies to reduce the burden cause by AMR foodborne pathogens.
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Affiliation(s)
- Qian Tao
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Qian Wu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Zhaohuan Zhang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- *Correspondence: Zhaohuan Zhang, ;
| | - Jing Liu
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Cuifang Tian
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Zhenhua Huang
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Pradeep K. Malakar
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
| | - Yingjie Pan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai, China
- Shanghai Engineering Research Center of Aquatic-Product Processing and Preservation, Shanghai, China
| | - Yong Zhao
- College of Food Science and Technology, Shanghai Ocean University, Shanghai, China
- Laboratory of Quality and Safety Risk Assessment for Aquatic Products on Storage and Preservation (Shanghai), Ministry of Agriculture and Rural Affairs, Shanghai, China
- Shanghai Engineering Research Center of Aquatic-Product Processing and Preservation, Shanghai, China
- Yong Zhao,
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Salman HA, Abdulmohsen AM, Falih MN, Romi ZM. Detection of multidrug-resistant Salmonella enterica subsp. enterica serovar Typhi isolated from Iraqi subjects. Vet World 2021; 14:1922-1928. [PMID: 34475718 PMCID: PMC8404135 DOI: 10.14202/vetworld.2021.1922-1928] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 06/18/2021] [Indexed: 11/16/2022] Open
Abstract
Background and Aim Enteric fever initiated by Salmonella enterica subsp. enterica serovar Typhi (S. Typhi) is among the most consistent disease worldwide, particularly in developing countries. The present study aimed to isolate and identify S. Typhi from typhoid suspected patients and determine their antibacterial susceptibility testing. Materials and Methods Thirty blood samples were collected from typhoid suspected patients in Baghdad, Iraq. The samples were cultured on SS agar and XLD agar for screening of S. Typhi. The suspected colonies were picked up and subjected to Vitek 2 compact for biochemical identification and antibacterial susceptibility testing of the organisms. Molecular identification of the isolates was performed by real-time polymerase chain reaction (RT-PCR). Results Black colonies were observed on cultured plates. Out of 30 samples, 27 and 29 isolates were identified as S. Typhi using Vitek 2 compact and RT-PCR, respectively. The data of the present study revealed that the strains of S. Typhi were showing multidrug resistance. All S. Typhi strains exhibited resistance to penicillins (ticarcillin and piperacillin), cephalosporins 4th G (cefepime), and monobactam (aztreonam). However, all the strains showed susceptibility against carbapenems (imipenem and meropenem) and tetracycline (minocycline). Conclusion RT-PCR and Vitek 2 compact showed a high level of accuracy in the detection of S. Typhi. Multidrug resistance was observed, which is an alert for the reduction of antibiotic consumption.
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Affiliation(s)
- Hamzah Abdulrahman Salman
- Department of Medical Laboratory Techniques, College of Medical Sciences Techniques, The University of Mashreq, Baghdad, Iraq
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Knabl L, Huber S, Lass-Flörl C, Fuchs S. Comparison of novel approaches for expedited pathogen identification and antimicrobial susceptibility testing against routine blood culture diagnostics. Lett Appl Microbiol 2021; 73:2-8. [PMID: 33788299 PMCID: PMC8252793 DOI: 10.1111/lam.13481] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 03/18/2021] [Indexed: 12/14/2022]
Abstract
Blood stream infections pose a major challenge for clinicians as the immediate application of an appropriate antibiotic treatment is the vital factor to safe the patients' lives. This preliminary study compares three different systems promising fast pathogen identification and susceptibility testing in comparison to conventional blood culture (BC): (i) the rapid antimicrobial susceptibility testing protocol according to EUCAST in combination with the Sepsityper® kit (sRAST), (ii) the direct inoculation method on the VITEK®2 system (dVIT) and (iii) testing with the Accelerate Pheno® system (AccPh). All methods were assessed in terms of accuracy, time to result and usability. Twenty‐three BC samples obtained from patients suffering from proven sepsis were analysed in detail. Pathogen identification was successful in 95·6, 91·3 and 91·3% in sRAST, dVIT and AccPh, respectively. Categorical agreement in antimicrobial susceptibility testing was 89·5, 96 and 96·6%, respectively. Time to result from sample entry to reporting ranged from an average of 4·6 h for sRAST and 6·9 h for AccPh to 10·6 h for dVIT. These results imply a significant shortening of reporting times at considerably high agreement rates for these new diagnostic approaches.
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Affiliation(s)
- L Knabl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - S Huber
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - C Lass-Flörl
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
| | - S Fuchs
- Institute of Hygiene and Medical Microbiology, Medical University of Innsbruck, Innsbruck, Austria
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16
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Chan E, Leroi M. Evaluation of the VITEK 2 Advanced Expert System performance for predicting resistance mechanisms in Enterobacterales acquired from a hospital-based screening program. Pathology 2021; 53:763-767. [PMID: 33958177 DOI: 10.1016/j.pathol.2021.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 12/31/2020] [Accepted: 01/11/2021] [Indexed: 11/19/2022]
Abstract
There is limited literature examining the accuracy of the VITEK 2 Advanced Expert System (AES) in characterisation of β-lactamase resistance patterns. We present a prospective single centre study to better ascertain the performance characteristics of this program. The VITEK 2 AES interpretation was compared to established laboratory phenotypic methods. The overall sensitivity for detection of broad-spectrum β-lactamase by the AES was 95%, with a specificity of 78%. One or more discrepancies were noted in 36% of samples, with the majority of these (87/100) due to incorrect 'overcall' of a resistance mechanism. AES characterisation of AmpC resistance mechanisms was excellent. In contrast, the AES had poor specificity in classifying extended spectrum β-lactamases (ESBLs). As a screening aid, the AES can be a valuable tool. However, optimal use requires an adequate working knowledge of resistance mechanisms in order to correctly interpret and accept the result output.
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Affiliation(s)
- Eddie Chan
- Department of Microbiology, Austin Health, Heidelberg, Vic, Australia; Department of Infectious Diseases, Austin Health, Heidelberg, Vic, Australia.
| | - Marcel Leroi
- Department of Microbiology, Austin Health, Heidelberg, Vic, Australia; Department of Infectious Diseases, Austin Health, Heidelberg, Vic, Australia
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Aljabo A, Mueller E, Abdul-Azeez D, Hoare T, Jain A. Gravity steam reprocessing in healthcare facilities for the reuse of N95 respirators. J Hosp Infect 2020; 106:698-708. [PMID: 33017616 PMCID: PMC7530561 DOI: 10.1016/j.jhin.2020.09.032] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 09/17/2020] [Accepted: 09/27/2020] [Indexed: 02/02/2023]
Abstract
BACKGROUND Coronavirus disease 2019 (COVID-19) has significantly impacted the health of millions of people around the world. The shortage of personal protective equipment, including N95 respirators, in hospital facilities has put frontline healthcare professionals at high risk for contracting this virus. AIM To develop a reproducible and safe N95 respirator reprocessing method that satisfies all presented regulatory standards and that can be directly implemented by hospitals using existing available equipment. METHODS A non-toxic gravity steam reprocessing method has been developed for the reuse of N95 respirators consisting of 30 min of steam treatment at 121°C followed by 30 min of heat drying. Samples of model number 1860, 1860s, 1870+, and 9105 N95 respirators were either collected from hospitals (for microbiology testing) or purchased new (for functionality testing), with all functionality tests (i.e. filter efficiency, fit evaluation, and strap integrity) performed at the Centers for Disease Control and Prevention using standard procedures established by the National Institute for Occupational Safety and Health. FINDINGS All tested models passed the minimum filter efficiency of 95% after three cycles of gravity steam reprocessing. The 1870+ N95 respirator model is the most promising model for reprocessing based on its efficient bacterial inactivation coupled with the maintenance of all other key functional respirator properties after multiple reprocessing steps. CONCLUSIONS The gravity steam method can effectively reprocess N95 respirators over at least three reprocessing cycles without negatively impacting the functionality requirements set out by regulators. Enabling the reuse of N95 respirators is a crucial tool for managing both the current pandemic and future healthcare crises.
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Affiliation(s)
- A Aljabo
- SteriPro Canada, Inc., Mississauga, Ontario, Canada.
| | - E Mueller
- Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - D Abdul-Azeez
- Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - T Hoare
- Department of Chemical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - A Jain
- SteriPro Canada, Inc., Mississauga, Ontario, Canada
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Xiao X, Tian H, Cheng X, Li G, Zhou J, Peng Z, Li Y. Pandoraea sputorum Bacteremia In A Patient Who Had Undergone Allogeneic Liver Transplantation Plus Immunosuppressive Therapy: A Case Report. Infect Drug Resist 2019; 12:3359-3364. [PMID: 31695454 PMCID: PMC6821047 DOI: 10.2147/idr.s227643] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Accepted: 10/12/2019] [Indexed: 01/01/2023] Open
Abstract
Pandoraea sputorum (P. sputorum), an emerging pathogen, is able to trigger a pronounced pro-inflammatory response that results in lung dysfunction in cystic fibrosis (CF) patients. All previous P. sputorum isolates have been obtained from the respiratory samples of CF patients, with no reported cases of P. sputorum bacteremia. For the first time, we report P. sputorum isolates recovered twice from the blood cultures of a patient with liver cancer who had undergone allogeneic liver transplantation. These isolates were successfully identified by combining mass spectrometry and molecular techniques based on 16S rRNA sequencing methods. At the onset of the P. sputorum bacteremia, the patient’s peripheral T, B and NK cell counts were 181.68/μL, 59.57/μL and 70.66/μL, respectively. The serum procalcitonin level, C-reactive protein level and peripheral neutrophil granulocyte percentage were 0.56 ng/mL, 61.00 mg/L and 96.8%, respectively. We found these isolates to be susceptible to ciprofloxacin and piperacillin/tazobactam and to be intermediate to amikacin. Previous studies have found P. sputorum isolates to be resistant. All of the data combined showed that compromised immune function from allogeneic liver transplantation plus immunosuppressive therapy contributes to the occurrence of P. sputorum bacteremia. Furthermore, the P. sputorum isolates demonstrated characteristic resistance profiles.
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Affiliation(s)
- Xiao Xiao
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China
| | - Hongpan Tian
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China
| | - Xiaohuan Cheng
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China
| | - Guoming Li
- Health Inspection and Testing Institute, Hubei Provincial Center for Disease Control and Prevention, Wuhan, People's Republic of China
| | - Junying Zhou
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China
| | - Zhiyong Peng
- Department of Critical Care Medicine, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China
| | - Yirong Li
- Department of Clinical Laboratory, Zhongnan Hospital of Wuhan University, Wuhan, People's Republic of China
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Sant' Anna D, Sampaio JLM, Sommaggio LRD, Mazzeo DEC, Marin-Morales MA, Marson FAL, Levy CE. The applicability of gene sequencing and MALDI-TOF to identify less common gram-negative rods (Advenella, Castellaniella, Kaistia, Pusillimonas and Sphingobacterium) from environmental isolates. Antonie van Leeuwenhoek 2019; 113:233-252. [PMID: 31560092 DOI: 10.1007/s10482-019-01333-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Accepted: 09/13/2019] [Indexed: 11/26/2022]
Abstract
Our aim was to identify less common non-fermenting gram-negative rods during the bioremediation process. Five genera were found: Advenella, Castellaniella, Kaistia, Pusillimonas and Sphingobacterium, for a total of 15 isolates. Therefore, we evaluated the applicability of four methods currently available for bacteria identification: (1) conventional biochemical methods, (2) the VITEK®-2 system, (3) MALDI-TOF mass spectrometry and (4) 16S rRNA gene sequencing. The biochemical methods and the VITEK®-2 system were reliable only for the Sphingobacterium isolate and solely at the genus level. Both MALDI-TOF mass spectrometry platforms (Bruker and VITEK® MS) did not achieve reliable identification results for any of these genera. 16S rRNA gene sequencing identified eight isolates to the species level but not to the subspecies level, when applicable. The remaining seven isolates were reliably identified through 16S rRNA gene sequencing to the genus level only. Our findings suggest that the detection and identification of less common genera (and species) that appeared at certain moments during the bioremediation process can be a challenge to microbiologists considering the most used techniques. In addition, more studies are required to confirm our results.
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Affiliation(s)
- Débora Sant' Anna
- Microbiology Laboratory, Department of Clinical Pathology, Faculty of Medical Sciences, University of Campinas, Rua Tessália Vieira de Camargo, 126, Cidade Universitária, Campinas, São Paulo, 13083-887, Brazil.
- Molecular Oncology Research Center, Barretos Cancer Hospital, Rua Antenor Duarte Villela, 1331, Barretos, São Paulo, Brazil.
| | - Jorge Luiz Mello Sampaio
- Microbiology Section, Fleury-Centers for Diagnostic Medicine, Av. General Waldomiro de Lima 508, São Paulo, 04344-070, Brazil
- Clinical Analysis and Toxicology Department, School of Pharmacy, University of São Paulo, Av. Professor Lineu Prestes, 580, Butantã, São Paulo, 05508-000, Brazil
| | - Lais Roberta Deroldo Sommaggio
- Department of Biology, Institute of Biosciences, São Paulo State University - Rio Claro, Av. 24 A, 1515, Bela Vista, Rio Claro, São Paulo, 13506-900, Brazil
| | - Dânia Elisa Christofoletti Mazzeo
- Department of Analytical Chemistry, Institute of Chemistry, São Paulo State University - Araraquara, Rua Professor Francisco Degni, 55, Araraquara, São Paulo, 14800-060, Brazil
| | - Maria Aparecida Marin-Morales
- Department of Biology, Institute of Biosciences, São Paulo State University - Rio Claro, Av. 24 A, 1515, Bela Vista, Rio Claro, São Paulo, 13506-900, Brazil
| | - Fernando Augusto Lima Marson
- Department of Pediatrics, Faculty of Medical Sciences, University of Campinas, Rua Tessália Vieira de Camargo, 126, Cidade Universitária, Campinas, São Paulo, 13083-887, Brazil.
- Laboratory of Pulmonary Physiology, Center for Pediatrics Investigation, Faculty of Medical Sciences, University of Campinas, Rua Tessália Vieira de Camargo, 126, Cidade Universitária, Campinas, São Paulo, 13083-887, Brazil.
- Department of Medical Genetics and Genomic Medicine, Faculty of Medical Sciences, University of Campinas, Rua Tessália Vieira de Camargo, 126, Cidade Universitária, Campinas, São Paulo, 13083-887, Brazil.
- Post-Graduate Program in Health Science, São Francisco University, Avenida São Francisco de Assis, 218, Cidade Universitária, Bragança Paulista, São Paulo, 12916-400, Brazil.
| | - Carlos Emílio Levy
- Microbiology Laboratory, Department of Clinical Pathology, Faculty of Medical Sciences, University of Campinas, Rua Tessália Vieira de Camargo, 126, Cidade Universitária, Campinas, São Paulo, 13083-887, Brazil.
- Department of Pediatrics, Faculty of Medical Sciences, University of Campinas, Rua Tessália Vieira de Camargo, 126, Cidade Universitária, Campinas, São Paulo, 13083-887, Brazil.
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20
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Wu S, Xu J, Qiu C, Xu L, Chen Q, Wang X. Direct antimicrobial susceptibility tests of bacteria and yeasts from positive blood cultures by using serum separator gel tubes and MALDI-TOF MS. J Microbiol Methods 2018; 157:16-20. [PMID: 30557587 DOI: 10.1016/j.mimet.2018.12.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 12/12/2018] [Accepted: 12/13/2018] [Indexed: 12/25/2022]
Abstract
Early and appropriate antimicrobial treatment can effectively reduce the mortality rate caused by bloodstream infections (BSIs) and is critical for favorable patient outcomes. In general, >90% of positive blood cultures will show positive results within 48 h after incubation in the BACTECTM FX system. However, an additional 6-8 h are required to obtain clones of the bacterium and another 10-24 h to obtain antimicrobial susceptibility test (AST) results. In this study, direct ASTs of bacteria and yeasts from positive blood cultures were performed by using serum separator gel tubes and matrix-assisted laser desorption ionization-time of flight mass spectrometry(MALDI-TOF MS). 153 BSI cases were caused by a single pathogen. The coincidence rates of genus and species identification between the direct method (from positive blood cultures) and reference method (from subcultured clones) were 86.9% and 83%, respectively. On average, 98.6% of the direct ASTs in 88 Gram-negative bacteria tested had an accurate result compared to the reference method. In Gram- positive bacteria and yeasts, the accuracy rates were 99.2% and 100%, respectively. MALDI-TOF MS combined with serum separator gel tubes can be used for rapidly identifying and performing ASTs on positive blood cultures.
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Affiliation(s)
- Shenghai Wu
- Department of Laboratory, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Jie Xu
- Department of Laboratory, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Chunning Qiu
- Department of Laboratory, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Lihui Xu
- Department of Laboratory, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Qiong Chen
- Department of Laboratory, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Zhejiang, China
| | - Xianjun Wang
- Department of Laboratory, Affiliated Hangzhou First People's Hospital, Zhejiang University School of Medicine, Zhejiang, China.
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Performance of the matrix-assisted laser desorption ionization time-of-flight mass spectrometry system for rapid identification of streptococci: a review. Eur J Clin Microbiol Infect Dis 2017; 36:1005-1012. [DOI: 10.1007/s10096-016-2879-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 12/13/2016] [Indexed: 11/30/2022]
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22
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Monteiro ACM, Fortaleza CMCB, Ferreira AM, Cavalcante RDS, Mondelli AL, Bagagli E, da Cunha MDLRDS. Comparison of methods for the identification of microorganisms isolated from blood cultures. Ann Clin Microbiol Antimicrob 2016; 15:45. [PMID: 27496125 PMCID: PMC4974807 DOI: 10.1186/s12941-016-0158-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2016] [Accepted: 07/14/2016] [Indexed: 11/12/2022] Open
Abstract
Background Bloodstream infections are responsible for thousands of deaths each year. The rapid identification of the microorganisms causing these infections permits correct therapeutic management that will improve the prognosis of the patient. In an attempt to reduce the time spent on this step, microorganism identification devices have been developed, including the VITEK® 2 system, which is currently used in routine clinical microbiology laboratories. Methods This study evaluated the accuracy of the VITEK® 2 system in the identification of 400 microorganisms isolated from blood cultures and compared the results to those obtained with conventional phenotypic and genotypic methods. In parallel to the phenotypic identification methods, the DNA of these microorganisms was extracted directly from the blood culture bottles for genotypic identification by the polymerase chain reaction (PCR) and DNA sequencing. Results The automated VITEK® 2 system correctly identified 94.7 % (379/400) of the isolates. The YST and GN cards resulted in 100 % correct identifications of yeasts (15/15) and Gram-negative bacilli (165/165), respectively. The GP card correctly identified 92.6 % (199/215) of Gram-positive cocci, while the ANC card was unable to correctly identify any Gram-positive bacilli (0/5). Conclusions The performance of the VITEK® 2 system was considered acceptable and statistical analysis showed that the system is a suitable option for routine clinical microbiology laboratories to identify different microorganisms.
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Affiliation(s)
- Aydir Cecília Marinho Monteiro
- Departamento de Microbiologia e Imunologia, Instituto de Biociências de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Carlos Magno Castelo Branco Fortaleza
- Departamento de Doenças Tropicais, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Adriano Martison Ferreira
- Laboratório de Análises Clínicas do Hospital das Clínicas de Botucatu, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Ricardo de Souza Cavalcante
- Comissão de Controle de Infecção Relacionada à Assistência à Saúde, Hospital das Clínicas, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Alessandro Lia Mondelli
- Departamento de Clínica Médica, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Eduardo Bagagli
- Departamento de Microbiologia e Imunologia, Instituto de Biociências de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil
| | - Maria de Lourdes Ribeiro de Souza da Cunha
- Departamento de Microbiologia e Imunologia, Instituto de Biociências de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil. .,Departamento de Doenças Tropicais, Faculdade de Medicina de Botucatu, UNESP-Univ. Estadual Paulista, Distrito de Rubião Junior, s/n, Botucatu, SP, CEP: 18618-970, Brazil.
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Automated Scoring of Chromogenic Media for Detection of Methicillin-Resistant Staphylococcus aureus by Use of WASPLab Image Analysis Software. J Clin Microbiol 2015; 54:620-4. [PMID: 26719443 PMCID: PMC4767952 DOI: 10.1128/jcm.02778-15] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Accepted: 12/04/2015] [Indexed: 01/04/2023] Open
Abstract
Recently, systems have been developed to create total laboratory automation for clinical microbiology. These systems allow for the automation of specimen processing, specimen incubation, and imaging of bacterial growth. In this study, we used the WASPLab to validate software that discriminates and segregates positive and negative chromogenic methicillin-resistant Staphylococcus aureus (MRSA) plates by recognition of pigmented colonies. A total of 57,690 swabs submitted for MRSA screening were enrolled in the study. Four sites enrolled specimens following their standard of care. Chromogenic agar used at these sites included MRSASelect (Bio-Rad Laboratories, Redmond, WA), chromID MRSA (bioMérieux, Marcy l'Etoile, France), and CHROMagar MRSA (BD Diagnostics, Sparks, MD). Specimens were plated and incubated using the WASPLab. The digital camera took images at 0 and 16 to 24 h and the WASPLab software determined the presence of positive colonies based on a hue, saturation, and value (HSV) score. If the HSV score fell within a defined threshold, the plate was called positive. The performance of the digital analysis was compared to manual reading. Overall, the digital software had a sensitivity of 100% and a specificity of 90.7% with the specificity ranging between 90.0 and 96.0 across all sites. The results were similar using the three different agars with a sensitivity of 100% and specificity ranging between 90.7 and 92.4%. These data demonstrate that automated digital analysis can be used to accurately sort positive from negative chromogenic agar cultures regardless of the pigmentation produced.
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Kalra D, Sati A, Shankar S, Jha A. Corneal infection by Pseudomonas stutzeri following excision of trigeminal nerve schwannoma. BMJ Case Rep 2015; 2015:bcr-2014-207496. [PMID: 25878226 DOI: 10.1136/bcr-2014-207496] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
A 25-year-old woman underwent intracranial surgery for trigeminal nerve schwannoma (TGNS) with persistent left-sided facial hypoaesthesia. Two months later, she developed a central corneal ulceration. Scraping of the corneal lesion revealed Gram-negative bacilli. Genus level identification was achieved using standard techniques and species level identification, revealing Pseudomonas stutzeri, was aided by a VITEK 2 compact system. Broad-spectrum fortified antibiotics were initially started followed by species-sensitive fortified antibiotics. Ocular surface toxicity developed a week later; this was managed with a non-fortified antibiotic. The epithelial defect healed in 3 weeks with subsequent corneal scar formation. Visual rehabilitation was achieved with deep anterior lamellar keratoplasty. Six months following surgery, the patient had a visual acuity of 20/40 with -1.25 170° -0.5 refractive correction and a clear graft. This case report, for the first time, highlights P. stutzeri, an aetiological agent of corneal ulcer following excision of TGNS and its successful management.
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Affiliation(s)
- Deepak Kalra
- Cornea & Anterior Segment Services, Command Hospital (EC), Kolkata, West Bengal, India
| | - Alok Sati
- Cornea & Anterior Segment Services, Command Hospital (EC), Kolkata, West Bengal, India
| | - Sandeep Shankar
- Department of Ophthalmology, Command Hospital (EC), Kolkata, West Bengal, India
| | - Ashok Jha
- Command Hospital (EC), Kolkata, West Bengal, India
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Hu JW, Cao MJ, Guo SC, Zhang LJ, Su WJ, Liu GM. Identification and inhibition of histamine-forming bacteria in blue scad (Decapterus maruadsi) and chub mackerel (Scomber japonicus). J Food Prot 2015; 78:383-9. [PMID: 25710155 DOI: 10.4315/0362-028x.jfp-14-296] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this study, we investigated the differences in histamine accumulation between blue scad and chub mackerel and methods of inhibiting histamine-forming bacteria and controlling histamine accumulation in fish. The free histidine contents in blue scad and chub mackerel were 1.45 and 2.75 mg/g, respectively. The histamine-forming bacteria isolated from them were identified as Citrobacter freundii, Citrobacter braakii, and Enterobacter aerogenes using 16S rDNA sequence analysis, the VITEK 2 Compact system, and MALDI-TOF MS. The histamine-producing capacities of C. freundii, C. braakii, and E. aerogenes were 470, 1,057, and 4,213 mg/liter, respectively, after culture at 37°C for 48 h. Among the different antimicrobials and preservatives tested, potassium sorbate and sodium diacetate effectively inhibited the histamine-forming bacteria and their histamine production. After chub mackerel was dipped into 0.5% potassium sorbate or sodium diacetate, its histamine content increased more slowly at room temperature. Therefore, a potassium sorbate or sodium diacetate dipping treatment could effectively control histamine accumulation in fish.
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Affiliation(s)
- Jia-Wei Hu
- College of Food and Biological Engineering, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Jimei University, Xiamen, Fujian, 361021, People's Republic of China
| | - Min-Jie Cao
- College of Food and Biological Engineering, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Jimei University, Xiamen, Fujian, 361021, People's Republic of China
| | - Shun-Cai Guo
- Jimei District Agricultural Technology Extension Training Center, Xiamen, Fujian, 361021, People's Republic of China
| | - Ling-Jing Zhang
- College of Food and Biological Engineering, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Jimei University, Xiamen, Fujian, 361021, People's Republic of China
| | - Wen-Jin Su
- College of Food and Biological Engineering, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Jimei University, Xiamen, Fujian, 361021, People's Republic of China
| | - Guang-Ming Liu
- College of Food and Biological Engineering, Fujian Collaborative Innovation Center for Exploitation and Utilization of Marine Biological Resources, Jimei University, Xiamen, Fujian, 361021, People's Republic of China.
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Inducible resistance to clindamycin in Staphylococcus aureus: validation of Vitek-2 against CLSI D-test. Pathology 2013; 45:181-4. [PMID: 23277176 DOI: 10.1097/pat.0b013e32835cccda] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS Inducible resistance to clindamycin in Staphylococcus aureus is common but not easily identified by routine testing, and can result in treatment failure if not detected. The gold standard method is the D-test described by the Clinical and Laboratory Standards Institute (CLSI). The Vitek-2 AST-P612 card contains an 'inducible clindamycin resistance' (ICR) test. We aimed to determine the accuracy of the Vitek-2 ICR test compared to the D-test. METHODS Isolates of erythromycin non-susceptible, clindamycin susceptible Staphylococcus aureus were identified. Routine antimicrobial susceptibility testing was performed using the Vitek-2 AST-P612 card, including the ICR test, and compared against the D-test. RESULTS 217 isolates were obtained. All of the 191 isolates that were ICR positive were D-test positive. Of the 27 ICR negative isolates, 10 (37%) were D-test positive [9 methicillin-sensitive S. aureus (MSSA), 1 methicillin-resistant S. aureus (MRSA)]. This correlates with a specificity of 100%, sensitivity of 95%, positive predictive value of 100%, and negative predictive value of 72%. CONCLUSIONS The ICR test is reliable in the presence of a positive result; however there is a false negative rate of approximately one in four. This will lead to susceptibility reporting errors, with potentially serious clinical implications. A negative ICR should be confirmed by CLSI D-test before reporting clindamycin as susceptible where the organism is not susceptible to erythromycin.
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Jordana-Lluch E, Martró Català E, Ausina Ruiz V. [Mass spectrometry in the clinical microbiology laboratory]. Enferm Infecc Microbiol Clin 2012; 30:635-44. [PMID: 22381225 PMCID: PMC7103318 DOI: 10.1016/j.eimc.2012.01.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 12/23/2011] [Accepted: 01/04/2012] [Indexed: 11/30/2022]
Abstract
Infectious diseases are still a cause of high mortality and morbidity rates. Current microbiological diagnostic methods are based on culture and phenotypic identification of isolated microorganisms, which can be obtained in about 24-48 h. Given that the microbiological identification is of major importance for patient management, new diagnostic methods are needed in order to detect and identify microorganisms in a timely and accurate manner. Over the last few years, several molecular techniques based on the amplification of microbial nucleic acids have been developed with the aim of reducing the time needed for the identification of the microorganisms involved in different infectious processes. On the other hand, mass spectrometry has emerged as a rapid and consistent alternative to conventional methods for microorganism identification. This review describes the most widely used mass spectrometry technologies -matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) and electrospray ionization time-of-flight (ESI-TOF)-, both for protein and nucleic acid analysis, as well as the commercial platforms available. Related publications of most interest in clinical microbiology are also reviewed.
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Affiliation(s)
- Elena Jordana-Lluch
- Servicio de Microbiología, Fundación Instituto de Investigación en Ciencias de la Salud Germans Trias y Pujol, Hospital Universitario Germans Trias y Pujol, Universidad Autónoma de Barcelona, Badalona, Barcelona, España
| | - Elisa Martró Català
- Servicio de Microbiología, Fundación Instituto de Investigación en Ciencias de la Salud Germans Trias y Pujol, Hospital Universitario Germans Trias y Pujol, Universidad Autónoma de Barcelona, Badalona, Barcelona, España
- CIBER Epidemiología y Salud Pública (CIBERESP), Barcelona, España
| | - Vicente Ausina Ruiz
- Servicio de Microbiología, Fundación Instituto de Investigación en Ciencias de la Salud Germans Trias y Pujol, Hospital Universitario Germans Trias y Pujol, Universidad Autónoma de Barcelona, Badalona, Barcelona, España
- CIBER Enfermedades Respiratorias (CIBERES), Bunyola, Mallorca, España
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Rapid identification of international multidrug-resistant Pseudomonas aeruginosa clones by multiple-locus variable number of tandem repeats analysis and investigation of their susceptibility to lytic bacteriophages. Antimicrob Agents Chemother 2012; 56:6175-80. [PMID: 22985882 DOI: 10.1128/aac.01233-12] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The objective of this study was to determine the genetic diversity of multidrug-resistant (MDR) Pseudomonas aeruginosa strains isolated over a period of 12 months in two French hospitals and to test their susceptibility to bacteriophages. A total of 47 MDR isolates recovered from hospitalized patients were genotyped using multiple-locus variable number of tandem repeats analysis. The genotypes were distributed into five clones (including 19, 5, 5, 3, and 3 isolates, respectively) and 12 singletons. Comparison to 77 MDR strains from three other countries, and MLST analysis of selected isolates showed the predominance of international MDR clones. The larger clone, CC235, contained 59 isolates displaying different antibiotic resistance mechanisms, including the presence of the GES1, VIM-2, VIM-4, and IMP-1 β-lactamases. Three newly isolated P. aeruginosa bacteriophages were found to lyse 42 of the 44 analyzed strains, distributed into the different clonal complexes. This pilot study suggests that systematic genotyping of P. aeruginosa MDR strains could improve our epidemiological understanding of transmission at both the local (hospital) and the national level and that phage therapy could be an alternative or a complementary treatment to antibiotics for treating MDR-infected patients.
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Ahmed NH, Baba K, Clay C, Lekalakala R, Hoosen AA. In vitro activity of tigecycline against clinical isolates of carbapenem resistant Acinetobacter baumannii complex in Pretoria, South Africa. BMC Res Notes 2012; 5:215. [PMID: 22554305 PMCID: PMC3422175 DOI: 10.1186/1756-0500-5-215] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2011] [Accepted: 05/03/2012] [Indexed: 11/21/2022] Open
Abstract
Background The presence of multi-drug resistant Acinetobacter baumannii raises a big therapeutic challenge in our hospital. Tigecycline, a new glycylcycline with expanded broad spectrum of activity against multi-drug resistant organisms was recently licensed in South Africa. Aim The aim of this study was to evaluate the in vitro activity of tigecycline against carbapenem resistant A. baumannii complex. Methods Consecutive clinical isolates of carbapenem resistant A. baumannii complex were collected between February and July 2010. Species identification and susceptibility testing was performed by Vitek-2 colorimetric compact system with Advanced Expert System (AES). Strains were tested for carbapenemase production by the modified Hodge test, according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Results A total of 232 carbapenem resistant clinical isolates of A. baumannii complex were collected over the six months study period; 217 (93.5%) of these were modified Hodge test positive. All isolates were susceptible to colistin and 174 (78%) susceptible to amikacin whilst 20 (9%) were susceptible to ciprofloxacin. For tigecycline 169 (75.8%) were fully susceptible, 37 (16.6%) intermediately resistant and only 17 (7.6%) were fully resistant. None of the carbapenem resistant isolates were susceptible to ampicillin, amoxicillin/clavullanic acid, piperacillin/tazobactam, cefuroxime, cefuroxime axetil, cefoxitin, cefepime or nitrofurantoin. Conclusion All carbapenem resistant isolates were found to be fully susceptible to colistin; amikacin and tigecycline susceptibility was 78% and 76% respectively. Treatment options for infections due to carbapenem and multi-drug resistant A. baumannii organisms are limited and hence tigecycline and amikacin may be considered. The properties of tigecycline i.e. stability, safety, low toxicity, non cross-resistance with other antibiotics and its efficacy against multi-drug resistant A. baumannii isolates make it a good choice. However, ongoing monitoring of A. baumannii susceptibility to tigecycline is needed.
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Affiliation(s)
- Nahid H Ahmed
- Department of Medical Microbiology, Faculty of Health Sciences, University of Pretoria, Prinshof Campus, Pathology Building, 5 Bophelo Road, Private Bag X323, Code: 0007, Riviera, Pretoria 0084, South Africa.
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Three-locus identification, genotyping, and antifungal susceptibilities of medically important Trichosporon species from China. J Clin Microbiol 2011; 49:3805-11. [PMID: 21900517 DOI: 10.1128/jcm.00937-11] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Three reference and 45 clinical isolates of Trichosporon were analyzed by conventional phenotypic and molecular methods to determine the species and genotypes of Trichosporon isolates from China. Target loci for molecular methods included the internal transcribed spacer (ITS) region, the D1/D2 domain of the 26S rRNA gene, and the intergenic spacer 1 (IGS1) region. Identification of eight Trichosporon species was achieved, of which Trichosporon asahii was the most common. Of the sequence-based molecular methods, the one targeting the D1/D2 domain assigned 97.9% (47/48) of isolates (seven species) correctly, while tests targeting both the ITS and IGS1 regions correctly identified all 48 isolates. The commercial API 20C AUX and Vitek 2 Compact YST systems correctly identified 91.9% and 73% of isolates when their biochemical profiles were queried against those of species contained in the databases, respectively, and misidentified 63.6% and 36.4% of isolates of species that were unclaimed by the databases, respectively. The predominant genotype among T. asahii clinical isolates, genotype 4 (51.4%), is rarely found in other countries. Voriconazole and itraconazole were the most active drugs in vitro against all the Trichosporon species tested, while caspofungin and amphotericin B demonstrated poor activity.
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Infection or colonization and antimicrobial susceptibility of Enterococcus spp at a regional hospital in Queretaro, Mexico. Am J Infect Control 2011; 39:615-6. [PMID: 21782284 DOI: 10.1016/j.ajic.2010.12.022] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2010] [Revised: 12/24/2010] [Accepted: 12/29/2010] [Indexed: 11/24/2022]
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Phoenix 100 versus Vitek 2 in the identification of gram-positive and gram-negative bacteria: a comprehensive meta-analysis. J Clin Microbiol 2011; 49:3284-91. [PMID: 21752980 DOI: 10.1128/jcm.00182-11] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Phoenix 100 and Vitek 2 (operating with the current colorimetric cards) are commonly used in hospital laboratories for rapid identification of microorganisms. The present meta-analysis aims to evaluate and compare their performance on Gram-positive and Gram-negative bacteria. The MEDLINE database was searched up to October 2010 for the retrieval of relevant articles. Pooled correct identification rates were derived from random-effects models, using the arcsine transformation. Separate analyses were conducted at the genus and species levels; subanalyses and meta-regression were undertaken to reveal meaningful system- and study-related modifiers. A total of 29 (6,635 isolates) and 19 (4,363 isolates) articles were eligible for Phoenix and colorimetric Vitek 2, respectively. No significant differences were observed between Phoenix and Vitek 2 either at the genus (97.70% versus 97.59%, P = 0.919) or the species (92.51% versus 88.77%, P = 0.149) level. Studies conducted with conventional comparator methods tended to report significantly better results compared to those using molecular reference techniques. Speciation of Staphylococcus aureus was significantly more accurate in comparison to coagulase-negative staphylococci by both Phoenix (99.78% versus 88.42%, P < 0.00001) and Vitek 2 (98.22% versus 91.89%, P = 0.043). Vitek 2 also reached higher correct identification rates for Gram-negative fermenters versus nonfermenters at the genus (99.60% versus 95.90%, P = 0.004) and the species (97.42% versus 84.85%, P = 0.003) level. In conclusion, the accuracy of both systems seems modified by underlying sample- and comparator method-related parameters. Future simultaneous assessment of the instruments against molecular comparator procedures may facilitate interpretation of the current observations.
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Abstract
This review aims to discuss expert systems in general and how they may be used in medicine as a whole and clinical microbiology in particular (with the aid of interpretive reading). It considers rule-based systems, pattern-based systems, and data mining and introduces neural nets. A variety of noncommercial systems is described, and the central role played by the EUCAST is stressed. The need for expert rules in the environment of reset EUCAST breakpoints is also questioned. Commercial automated systems with on-board expert systems are considered, with emphasis being placed on the "big three": Vitek 2, BD Phoenix, and MicroScan. By necessity and in places, the review becomes a general review of automated system performances for the detection of specific resistance mechanisms rather than focusing solely on expert systems. Published performance evaluations of each system are drawn together and commented on critically.
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Affiliation(s)
- Trevor Winstanley
- Department of Microbiology, Royal Hallamshire Hospital, Sheffield, United Kingdom.
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Quan F, Liu G, Wang L, Wang X. Investigation of pulmonary infection pathogens in neurological intensive care unit. Ther Clin Risk Manag 2011; 7:21-5. [PMID: 21339939 PMCID: PMC3039010 DOI: 10.2147/tcrm.s15730] [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: 01/20/2011] [Indexed: 12/21/2022] Open
Abstract
Purpose: The purpose of this study is to investigate the distribution and antimicrobial susceptibility of pathogenic bacteria in inpatients with pulmonary infection in the neurological intensive care unit (NICU). Methods: A total of 947 sputum specimens of 428 inpatients from May 2007 to May 2008 in the NICU were enrolled in the study, and bacterial identification and antibiotic susceptibility tests were analyzed using a VITEK 2 system. Results: A total of 400 positive bacterial strains were separated from 947 sputum specimens, with Gram-negative bacteria accounting for 69.0% of the total strains collected. The most common strain of Gram-negative bacteria was Klebsiella pneumoniae (20.5%). Gram-positive bacteria accounted for 10.0% of the total strains, with the most common strain being Staphylococcus aureus (2.5%). Fungal species accounted for 21.0% of the total strains, and the most common strain collected was Candida albicans (12.25%). Imipenem was the most effective antibiotic against Gram-positive and Gram-negative bacteria. The drug resistance rate of Gram-positive bacteria to penicillin G was 100%, and the Gram-positive bacteria were 100% sensitive to teicoplanin, vancomycin, and linezolid. Conclusions: Gram-negative bacterial infections account for the majority of pulmonary infections in the NICU, with fungal infections being the second most common infection type observed. In addition, fungal infections seem to be related to mortality in the NICU.
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Affiliation(s)
- Fengying Quan
- Department of Neurology, The First Affiliated Hospital of Chongqing, Medical University, Chongqing, China
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Ceri M, Ortabozkoyun L, Altay M, Unverdi S, Kurultak I, Huddam B, Kilic F, Yilmaz R, Duranay M. Peritonitis Due to Pseudomonas stutzeri, an Organism That May Be Difficult to Culture. Perit Dial Int 2010; 30:484-6. [DOI: 10.3747/pdi.2009.00210] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- M. Ceri
- Department of Nephrology Ankara University Faculty of Medicine Ankara, Turkey
| | - L. Ortabozkoyun
- Department of Nephrology Ankara University Faculty of Medicine Ankara, Turkey
| | - M. Altay
- Department of Internal Medicine Ankara University Faculty of Medicine Ankara, Turkey
| | - S. Unverdi
- Department of Nephrology Ankara University Faculty of Medicine Ankara, Turkey
| | - I. Kurultak
- Ankara Education and Research Hospital Department of Nephrology Ankara University Faculty of Medicine Ankara, Turkey
| | - B. Huddam
- Department of Nephrology Ankara University Faculty of Medicine Ankara, Turkey
| | - F. Kilic
- Department of Internal Medicine Ankara University Faculty of Medicine Ankara, Turkey
| | - R. Yilmaz
- Department of Nephrology Ankara University Faculty of Medicine Ankara, Turkey
| | - M. Duranay
- Department of Nephrology Ankara University Faculty of Medicine Ankara, Turkey
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Behera B, Jain N, Sharma S, Mathur P, Misra MC. Antimicrobial activity of daptomycin against Staphylococcus aureus isolates from skin and skin structure infections of trauma patients. J Infect 2010; 61:195-6. [PMID: 20547179 DOI: 10.1016/j.jinf.2010.06.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2010] [Revised: 06/04/2010] [Accepted: 06/07/2010] [Indexed: 11/18/2022]
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Performance of an agar dilution method and a Vitek 2 card for detection of inducible clindamycin resistance in Staphylococcus spp. J Clin Microbiol 2010; 48:1354-7. [PMID: 20164285 DOI: 10.1128/jcm.01751-09] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The D-zone test detects inducible clindamycin resistance in Staphylococcus spp. Two other methods not described by the Clinical and Laboratory Standards Institute (CLSI) are available to test for this resistance mechanism: an agar dilution method and new Vitek 2 cards. This study evaluated the performance of both methods in detecting inducible clindamycin resistance. Nonduplicate clinical strains of Staphylococcus spp. (111 Staphylococcus aureus and 52 coagulase-negative staphylococcus strains), intermediate or resistant to erythromycin but susceptible to clindamycin, were obtained from three hospitals in Montreal, Quebec, Canada. Molecular analysis to detect resistance genes was conducted on all strains. A Mueller-Hinton agar containing 1 mg of erythromycin and 0.5 mg of clindamycin/liter was used for the dilution method, and two inocula were tested: 10(4) and 10(5) CFU per spot. Plates were read at 24 and 48 h. The Vitek 2 AST-P580 card was used according to the manufacturer's recommendations. The results were compared to those of the D-zone test. The D-zone test was positive in 134 of 163 (82%) strains. With the 10(4) CFU inoculum, the sensitivities were 84 and 99% at 24 and 48 h, respectively. The 10(5) CFU inoculum increased the sensitivities at 24 and 48 h to 91 and 100%, respectively. The specificity was 100% for the 10(4) CFU inoculum at 24 h and 97% for the other combinations. The sensitivity and specificity for the Vitek 2 card were 93 and 100%, respectively. The performance of both the agar dilution method and the Vitek 2 card was good, but these methods were not as sensitive as the D-zone test at 24 h.
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Performance of MicroScan WalkAway and Vitek 2 for detection of oxacillin resistance in a set of methicillin-resistant Staphylococcus aureus isolates with diverse genetic backgrounds. J Clin Microbiol 2009; 47:2623-5. [PMID: 19515835 DOI: 10.1128/jcm.02112-08] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Of 104 genotypically diverse methicillin-resistant Staphylococcus aureus (MRSA) isolates tested with the MicroScan WalkAway (Pos MIC 24 panel) and Vitek 2 (AST-P549 card) systems, 7 and 6 isolates, respectively, showed an oxacillin MIC of < or =2mg/liter. Most of these MRSA isolates were community acquired. However, if the cefoxitin screen of AST-P549 was also considered, MRSA detection failed for only one isolate.
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