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Wilson TK, Zishiri OT, El Zowalaty ME. Molecular detection of virulence genes in Staphylococcus aureus isolated from wild pigeons ( Columba domestica livia) in KwaZulu-Natal in South Africa. One Health 2024; 18:100656. [PMID: 38179313 PMCID: PMC10765103 DOI: 10.1016/j.onehlt.2023.100656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 01/06/2024] Open
Abstract
The current study aimed to determine virulence determinants among S. aureus isolated from wild pigeons and houseflies around hospital areas in the Greater Durban area, South Africa. Following enrichment and bacterial growth, DNA extraction using the boiling method was performed. Overall, 57 out of 252 samples (22.6%) were positive for S. aureus. Six known virulence genes were tested, where five known virulence determinants were positive and none of the S. aureus isolates were positive to coagulase (coa) gene. The highest prevalence rates were found in the genes encoding haemolysins, with the hla and hld genes having 8 (14%) and 9 (15.8%) positive isolates respectively. The sea, LukS/F-PV, and spa genes had 5 (8.8%), 4 (7%), and 2 (3.5%) positive isolates respectively. These results demonstrated the detection of pathogenic S. aureus from hospital environment in Durban, South Africa which may account for the emergence staphylococcal infections. The findings of the present study highlights the significant role of wild pigeons and houseflies as potenital infectious disease vectors in a One Health context.
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Affiliation(s)
- Trevor K. Wilson
- Discipline of Genetics, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Oliver T. Zishiri
- Discipline of Genetics, School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Private Bag X54001, Durban 4000, South Africa
| | - Mohamed E. El Zowalaty
- Veterinary Medicine and Food Security Research Groups, Medical Laboratory Sciences Program, Faculty of Health Sciences, Abu Dhabi Women's Campus, Higher Colleges of Technology, Abu Dhabi 41012, United Arab Emirates
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Somerville TF, Mdala S, Zungu T, Gandiwa M, Herbert R, Everett D, Corless CE, Beare NAV, Neal T, Horsburgh MJ, Darby A, Kaye SB, Kayange PC. Microbial keratitis in Southern Malawi: a microbiological pilot study. BMJ Open Ophthalmol 2024; 9:e001682. [PMID: 38653537 PMCID: PMC11043707 DOI: 10.1136/bmjophth-2024-001682] [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: 02/14/2024] [Accepted: 04/10/2024] [Indexed: 04/25/2024] Open
Abstract
OBJECTIVE Microbial keratitis (MK) is a significant cause of blindness in sub-Saharan Africa. We investigated the feasibility of using a novel corneal impression membrane (CIM) for obtaining and processing samples by culture, PCR and whole-genome sequencing (WGS) in patients presenting with suspected MK in Malawi. METHODS AND ANALYSIS Samples were collected from patients presenting with suspected MK using a 12 mm diameter polytetrafluoroethylene CIM disc. Samples were processed using culture and PCR for Acanthamoeba, herpes simplex virus type 1 (HSV-1) and the bacterial 16S rRNA gene. Minimum inhibitory concentrations of isolates to eight antimicrobials were measured using susceptibility strips. WGS was used to characterise Staphylococcus aureus isolates. RESULTS 71 eyes of 71 patients were included. The overall CIM isolation rate was 81.7% (58 positive samples from 71 participants). 69 (81.2%) of isolates were Gram-positive cocci. Coagulase-negative Staphylococcus 31.8% and Streptococcus species 14.1% were the most isolated bacteria. Seven (9.9%) participants were positive for HSV-1. Fungi and Acanthamoeba were not detected. Moxifloxacin and chloramphenicol offered the best coverage for both Gram-positive and Gram-negative isolates when susceptibility was determined using known antimicrobial first quartile concentrations and European Committee on Antimicrobial Susceptibility Testing breakpoints, respectively. WGS identified known virulence genes associated with S. aureus keratitis. CONCLUSIONS In a resource-poor setting, a CIM can be used to safely sample the cornea in patients presenting with suspected MK, enabling identification of causative microorganisms by culture and PCR. Although the microbiological spectrum found was limited to the dry season, these preliminary results could be used to guide empirical treatment.
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Affiliation(s)
- Tobi F Somerville
- Department of Eye and Vision Sciences, University of Liverpool, Liverpool, UK
| | - Shaffi Mdala
- Queen Elizabeth Central Hospital, Blantyre, Southern Region, Malawi
- Ophthalmology Unit, Kamuzu University of Health Sciences, Blantyre, Southern Region, Malawi
| | - Thokozani Zungu
- Queen Elizabeth Central Hospital, Blantyre, Southern Region, Malawi
- Ophthalmology Unit, Kamuzu University of Health Sciences, Blantyre, Southern Region, Malawi
| | - Moira Gandiwa
- Ophthalmology Unit, Kamuzu University of Health Sciences, Blantyre, Southern Region, Malawi
- Kamuzu Central Hospital, Lilongwe, Central Region, Malawi
| | - Rose Herbert
- Department of Eye and Vision Sciences, University of Liverpool, Liverpool, UK
| | - Dean Everett
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- College of Medicine and Health Sciences, Infection Research Unit, Khalifa University, Abu Dhabi, UAE
| | - Caroline E Corless
- Medical Microbiology, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
| | | | - Timothy Neal
- Department of Infection and Immunity, Liverpool University Hospitals NHS Foundation Trust, Liverpool, UK
| | - Malcolm J Horsburgh
- Department of Infection Biology and Microbiomes, University of Liverpool, Liverpool, UK
| | - Alistair Darby
- Department of Infection Biology and Microbiomes, University of Liverpool, Liverpool, UK
| | - Stephen B Kaye
- Department of Eye and Vision Sciences, University of Liverpool, Liverpool, UK
| | - Petros C Kayange
- Queen Elizabeth Central Hospital, Blantyre, Southern Region, Malawi
- Ophthalmology Unit, Kamuzu University of Health Sciences, Blantyre, Southern Region, Malawi
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Sara M, Yasir M, Kalaiselvan P, Hui A, Kuppusamy R, Kumar N, Chakraborty S, Yu TT, Wong EHH, Molchanova N, Jenssen H, Lin JS, Barron AE, Willcox M. The activity of antimicrobial peptoids against multidrug-resistant ocular pathogens. Cont Lens Anterior Eye 2024; 47:102124. [PMID: 38341309 PMCID: PMC11024869 DOI: 10.1016/j.clae.2024.102124] [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: 07/27/2023] [Revised: 01/11/2024] [Accepted: 02/04/2024] [Indexed: 02/12/2024]
Abstract
BACKGROUND Ocular infections caused by antibiotic-resistant pathogens can result in partial or complete vision loss. The development of pan-resistant microbial strains poses a significant challenge for clinicians as there are limited antimicrobial options available. Synthetic peptoids, which are sequence-specific oligo-N-substituted glycines, offer potential as alternative antimicrobial agents to target multidrug-resistant bacteria. METHODS The antimicrobial activity of synthesised peptoids against multidrug-resistant (MDR) ocular pathogens was evaluated using the microbroth dilution method. Hemolytic propensity was assessed using mammalian erythrocytes. Peptoids were also incubated with proteolytic enzymes, after which their minimum inhibitory activity against bacteria was re-evaluated. RESULTS Several alkylated and brominated peptoids showed good inhibitory activity against multidrug-resistant Pseudomonas aeruginosa strains at concentrations of ≤15 μg mL-1 (≤12 µM). Similarly, most brominated compounds inhibited the growth of methicillin-resistant Staphylococcus aureus at 1.9 to 15 μg mL-1 (12 µM). The N-terminally alkylated peptoids caused less toxicity to erythrocytes. The peptoid denoted as TM5 had a high therapeutic index, being non-toxic to either erythrocytes or corneal epithelial cells, even at 15 to 22 times its MIC. Additionally, the peptoids were resistant to protease activity. CONCLUSIONS Peptoids studied here demonstrated potent activity against various multidrug-resistant ocular pathogens. Their properties make them promising candidates for controlling vision-related morbidity associated with eye infections by antibiotic-resistant strains.
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Affiliation(s)
- Manjulatha Sara
- School of Optometry and Vision Science, UNSW Sydney, Australia.
| | - Muhammad Yasir
- School of Optometry and Vision Science, UNSW Sydney, Australia
| | | | - Alex Hui
- School of Optometry and Vision Science, UNSW Sydney, Australia; Centre for Ocular Research and Education, University of Waterloo, Canada
| | - Rajesh Kuppusamy
- School of Optometry and Vision Science, UNSW Sydney, Australia; School of Chemistry, UNSW Sydney, Australia
| | | | | | - Tsz Tin Yu
- School of Chemistry, UNSW Sydney, Australia
| | | | - Natalia Molchanova
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 4720, USA
| | - Håvard Jenssen
- Department of Science and Environment, Roskilde University, 4000 Roskilde, Denmark
| | - Jennifer S Lin
- Department of Bioengineering, School of Medicine & School of Engineering, Stanford University, Stanford, CA 9430, USA
| | - Annelise E Barron
- Department of Bioengineering, School of Medicine & School of Engineering, Stanford University, Stanford, CA 9430, USA
| | - Mark Willcox
- School of Optometry and Vision Science, UNSW Sydney, Australia.
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Sulikowska M, Marek A, Jarosz ŁS, Pyzik E, Stępień-Pyśniak D, Hauschild T. Pathogenic Potential of Coagulase-Positive Staphylococcus Strains Isolated from Aviary Capercaillies and Free-Living Birds in Southeastern Poland. Animals (Basel) 2024; 14:295. [PMID: 38254464 PMCID: PMC10812641 DOI: 10.3390/ani14020295] [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: 12/15/2023] [Revised: 01/12/2024] [Accepted: 01/16/2024] [Indexed: 01/24/2024] Open
Abstract
The aim of the study was to determine the occurrence and characteristics of coagulase-positive Staphylococcus strains in the carcasses of wild birds and aviary capercaillies in Southeastern Poland. In total, samples taken from 333 birds were examined. The material consisted of swabs from the internal organs of dead birds (heart, liver, and spleen), the tarsal joints, and mucous membranes (conjunctiva and palatine fissure), as well as from unhatched embryos. The isolated Staphylococcus strains were tested for sensitivity to nine antimicrobial agents and the presence of selected virulence genes. An analysis of the similarity of isolates within species was performed using pulsed-field gel electrophoresis (PFGE). The result indicates that coagulase-positive strains accounted for 5.7% and belonged to the species: Staphylococcus aureus, Staphylococcus pseudintermedius, and Staphylococcus delphini. Among isolated strains, 15.8% were multidrug resistant. The most frequently detected virulence genes were hla in 58% of isolates and hlb and hld in 47.4% of isolates. The results of multiplex PCR showed the presence of genes responsible for the production of enterotoxins C, B, E, and J, in single isolates. It can be concluded that coagulase-positive Staphylococcus strains accounted for a small percentage of staphylococci isolated from free-living birds in the study area. The occurrence of multidrug-resistant coagulase-positive Staphylococcus strains in aviary capercaillies suggests that they play a role in the transmission and spread of resistant strains into the environment. Free-living birds may also be a reservoir of enterotoxigenic Staphylococcus strains.
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Affiliation(s)
| | - Agnieszka Marek
- Department of Preventive Veterinary and Avian Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 20-950 Lublin, Poland; (E.P.)
| | - Łukasz Sebastian Jarosz
- Department of Epizootiology and Clinic of Infectious Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 20-612 Lublin, Poland
| | - Ewelina Pyzik
- Department of Preventive Veterinary and Avian Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 20-950 Lublin, Poland; (E.P.)
| | - Dagmara Stępień-Pyśniak
- Department of Preventive Veterinary and Avian Diseases, Faculty of Veterinary Medicine, University of Life Sciences in Lublin, 20-950 Lublin, Poland; (E.P.)
| | - Tomasz Hauschild
- Department of Microbiology and Biotechnology, Faculty of Biology, University of Bialystok, 15-245 Białystok, Poland
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Huertas-Bello M, Cuéllar-Sáenz JA, Rodriguez CN, Cortés-Vecino JA, Navarrete ML, Avila MY, Koudouna E. A Pilot Study to Evaluate Genipin in Staphylococcus aureus and Pseudomonas aeruginosa Keratitis Models: Modulation of Pro-Inflammatory Cytokines and Matrix Metalloproteinases. Int J Mol Sci 2023; 24:ijms24086904. [PMID: 37108070 PMCID: PMC10138382 DOI: 10.3390/ijms24086904] [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: 02/06/2023] [Revised: 03/30/2023] [Accepted: 04/01/2023] [Indexed: 04/29/2023] Open
Abstract
Infectious keratitis is a vision-threatening microbial infection. The increasing antimicrobial resistance and the fact that severe cases often evolve into corneal perforation necessitate the development of alternative therapeutics for effective medical management. Genipin, a natural crosslinker, was recently shown to exert antimicrobial effects in an ex vivo model of microbial keratitis, highlighting its potential to serve as a novel treatment for infectious keratitis. This study aimed to evaluate the antimicrobial and anti-inflammatory effects of genipin in an in vivo model of Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) keratitis. Clinical scores, confocal microscopy, plate count, and histology were carried out to evaluate the severity of keratitis. To assess the effect of genipin on inflammation, the gene expression of pro- and anti-inflammatory factors, including matrix metalloproteinases (MMPs), were evaluated. Genipin treatment alleviated the severity of bacterial keratitis by reducing bacterial load and repressing neutrophil infiltration. The expression of interleukin 1B (IL1B), interleukin 6 (IL6), interleukin 8 (IL8), interleukin 15 (IL15), tumor necrosis factor-α (TNF-α), and interferon γ (IFNγ), as well as MMP2 and MMP9, were significantly reduced in genipin-treated corneas. Genipin promoted corneal proteolysis and host resistance to S. aureus and P. aeruginosa infection by suppressing inflammatory cell infiltration, regulating inflammatory mediators, and downregulating the expression of MMP2 and MMP9.
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Affiliation(s)
- Marcela Huertas-Bello
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Jerson Andrés Cuéllar-Sáenz
- Grupo de Investigación Parasitología Veterinaria, Department of Animal Health, Faculty of Veterinary Medicine and Zootechnics, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Cristian Nicolas Rodriguez
- Department of Microbiology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Jesús Alfredo Cortés-Vecino
- Grupo de Investigación Parasitología Veterinaria, Department of Animal Health, Faculty of Veterinary Medicine and Zootechnics, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Myriam Lucia Navarrete
- Department of Microbiology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Marcel Yecid Avila
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
| | - Elena Koudouna
- Department of Ophthalmology, Faculty of Medicine, Bogota DC, Universidad Nacional de Colombia, Bogotá 111321, Colombia
- Structural Biophysics Group, School of Optometry and Vision Sciences, Cardiff University, Cardiff CF24 4HQ, UK
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Afzal M, Vijay AK, Stapleton F, Willcox M. The Relationship between Ciprofloxacin Resistance and Genotypic Changes in S. aureus Ocular Isolates. Pathogens 2022; 11:1354. [PMID: 36422605 PMCID: PMC9695201 DOI: 10.3390/pathogens11111354] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/26/2022] [Accepted: 11/10/2022] [Indexed: 07/28/2023] Open
Abstract
Staphylococcus aureus (S. aureus) is a frequent cause of eye infections with some isolates exhibiting increased antimicrobial resistance to commonly prescribed antibiotics. The increasing resistance of ocular S. aureus to ciprofloxacin is a serious concern as it is a commonly used as a first line antibiotic to treat S. aureus keratitis. This study aimed to analyse genetic mutations in the genomes of 25 S. aureus isolates from infections or non-infectious ocular conditions from the USA and Australia and their relationship to ciprofloxacin resistance. Overall, 14/25 isolates were phenotypically resistant to ciprofloxacin. All isolates were analyzed for mutations in their quinolone resistance-determining regions (QRDRs) and efflux pump genes. Of the fourteen resistant isolates, 9/14 had ciprofloxacin resistance mutations within their QRDRs, at codons 80 or 84 within the parC subunit and codon 84 within the gyrA subunit of DNA gyrase. The highest resistance (MIC = 2560 μg/mL) was associated with two SNPs in both gyrA and parC. Other resistant isolates (3/14) had mutations within norB. Mutations in genes of other efflux pumps and their regulator (norA, norC, mepA, mdeA, sepA, sdrM, mepR, arlR, and arlS) or the DNA mismatch repair (MMR) system (mutL and mutS) were not associated with increased resistance to ciprofloxacin. The functional mutations associated with ciprofloxacin resistance in QRDRs (gyrA and parC) and norB suggests that these are the most common reasons for ciprofloxacin resistance in ocular isolates. Novel SNPs of gyrA Glu-88-Leu, Asn-860-Thr and Thr-845-Ala and IIe-855-Met, identified in this study, need further gene knock out/in studies to better understand their effect on ciprofloxacin resistance.
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Afzal M, Vijay AK, Stapleton F, Willcox MDP. Genomics of Staphylococcus aureus Strains Isolated from Infectious and Non-Infectious Ocular Conditions. Antibiotics (Basel) 2022; 11:antibiotics11081011. [PMID: 36009880 PMCID: PMC9405196 DOI: 10.3390/antibiotics11081011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 07/25/2022] [Accepted: 07/26/2022] [Indexed: 01/08/2023] Open
Abstract
Staphylococcus aureus is a major cause of ocular infectious (corneal infection or microbial keratitis (MK) and conjunctivitis) and non-infectious corneal infiltrative events (niCIE). Despite the significant morbidity associated with these conditions, there is very little data about specific virulence factors associated with the pathogenicity of ocular isolates. A set of 25 S. aureus infectious and niCIEs strains isolated from USA and Australia were selected for whole genome sequencing. Sequence types and clonal complexes of S. aureus strains were identified by using multi-locus sequence type (MLST). The presence or absence of 128 virulence genes was determined by using the virulence finder database (VFDB). Differences between infectious (MK + conjunctivitis) and niCIE isolates from USA and Australia for possession of virulence genes were assessed using the chi-square test. The most common sequence types found among ocular isolates were ST5, ST8 while the clonal complexes were CC30 and CC1. Virulence genes involved in adhesion (ebh, clfA, clfB, cna, sdrD, sdrE), immune evasion (chp, esaD, esaE, esxB, esxC, esxD), and serine protease enzymes (splA, splD, splE, splF) were more commonly observed in infectious strains (MK + conjunctivitis) than niCIE strains (p = 0.004). Toxin genes were present in half of infectious (49%, 25/51) and niCIE (51%, 26/51) strains. USA infectious isolates were significantly more likely to possess splC, yent1, set9, set11, set36, set38, set40, lukF-PV, and lukS-PV (p < 0.05) than Australian infectious isolates. MK USA strains were more likely to possesses yent1, set9, set11 than USA conjunctivitis strains (p = 0.04). Conversely USA conjunctivitis strains were more likely to possess set36 set38, set40, lukF-PV, lukS-PV (p = 0.03) than MK USA strains. The ocular strain set was then compared to 10 fully sequenced non-ocular S. aureus strains to identify differences between ocular and non-ocular isolates. Ocular isolates were significantly more likely to possess cna (p = 0.03), icaR (p = 0.01), sea (p = 0.001), set16 (p = 0.01), and set19 (p = 0.03). In contrast non-ocular isolates were more likely to possess icaD (p = 0.007), lukF-PV, lukS-PV (p = 0.01), selq (p = 0.01), set30 (p = 0.01), set32 (p = 0.02), and set36 (p = 0.02). The clones ST5, ST8, CC30, and CC1 among ocular isolates generally reflect circulating non-ocular pathogenic S. aureus strains. The higher rates of genes in infectious and ocular isolates suggest a potential role of these virulence factors in ocular diseases.
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