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Ning K, Zhou R, Li M. Antimicrobial resistance and molecular typing of Staphylococcus aureus isolates from raw milk in Hunan Province. PeerJ 2023; 11:e15847. [PMID: 37663302 PMCID: PMC10470458 DOI: 10.7717/peerj.15847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 07/14/2023] [Indexed: 09/05/2023] Open
Abstract
Background Staphylococcus aureus is one of the most important foodborne pathogens in the world and the main cause of dairy cow mastitis. Few studies have investigated the epidemic pedigree of S. aureus of bovine origin in Hunan, China. Therefore, we aimed to analyze the capsular polysaccharides (CP), molecular typing, and antibiotic resistance characteristics of S. aureus isolated from raw milk of dairy farms in Hunan Province. Methods Between 2018 and 2022, 681 raw milk samples were collected from dairy cows from farms in Changsha, Changde, Shaoyang, Yongzhou, and Chenzhou in Hunan Province. S. aureus was isolated from these samples, and the isolates were subjected to molecular typing, CP typing, and determination of antibiotic resistance through broth dilution and polymerase chain reaction (PCR). Results From 681 raw milk samples, 76 strains of S. aureus were isolated. The pathogenicity of 76 isolates was determined preliminarily by detecting cp5 and cp8 CP genes. Eighteen types of antimicrobial resistance phenotypes of 76 S. aureus strains were detected by the broth dilution method, and 11 kinds of related resistance genes were amplified by PCR. The S. aureus isolates had CP5 (42.10%) and CP8 (57.89%). S. aureus had a multiple antimicrobial resistance rate of 26.75%. The isolated strains had the highest resistance rate to penicillin (82.89%) and showed varying degrees of resistance to other drugs, but no isolate showed resistance to doxycycline. The 76 isolates all carried two or more antibiotic resistance genes, with a maximum of eight antibiotics resistance genes. FemB was detected in all isolates, but none of isolates carried vanA, ermA, or glrA. The 76 isolates were divided into 22 sequence types (ST) and 20 spa types by MLST and spa typing, and the number of t796-ST7 (n = 15) isolates was the highest, which may be the major epidemic strain of multidrug-resistant S. aureus. Conclusion The present findings indicate the need to increase production of the CP8 S. aureus vaccine in Hunan Province and strengthen resistance monitoring of t796-ST7 isolates with the prevalent molecular type of multi-drug resistant strains. The use of β-lactam, macrolides, and lincosamides should be reduced; doxycycline, sulfonamides, and glycopeptides could be appropriately added to veterinary antibiotics to treat infectious diseases in dairy cows.
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Affiliation(s)
- Keming Ning
- College of Veterinary Medicine, Hunan Agricultural University, Hunan, China
| | - Rushun Zhou
- Hunan Provincial Institute of Veterinary Drugs and Feed Control, Hunan, China
| | - Manxiang Li
- College of Veterinary Medicine, Hunan Agricultural University, Hunan, China
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Gogoi-Tiwari J, Dorji D, Tiwari HK, Shirolkar G, Aleri JW, Mukkur T. Phenotypic PIA-Dependent Biofilm Production by Clinical Non-Typeable Staphylococcus aureus Is Not Associated with the Intensity of Inflammation in Mammary Gland: A Pilot Study Using Mouse Mastitis Model. Animals (Basel) 2021; 11:3047. [PMID: 34827779 DOI: 10.3390/ani11113047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/24/2021] [Accepted: 10/15/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary Staphylococcus aureus-associated human clinical infections are predominantly caused by the encapsulated strains, with non-typeable strains representing less than 25%. In contrast, 80% of the S. aureus from bovine mastitis cases are non-typeable as they do not possess the Capsular Types 1, 2, 5, and 8. In our previous studies, it was demonstrated that the extent of mammary tissue damage was associated with the strength of biofilms formed by encapsulated S. aureus strains. This study assesses the impact of biofilm formation, as a virulence factor of non-typeable Staphylococcus aureus, causing mammary tissue damage in a mouse mastitis model. The study demonstrates no association between the strength of biofilm production by non-typeable S. aureus and the mammary tissue damage. However, the mice infected with strong biofilm producing non-typeable S. aureus died 6h earlier than those infected with weak biofilm producing non-typeable S. aureus suggesting the role of biofilm in the advancement of the time of mice mortality. Abstract Non-typeable (NT) Staphylococcus aureus strains are associated with chronic bovine mastitis. This study investigates the impact of biofilm formation by clinical NT S. aureus on cytokine production and mammary tissue damage by using a mouse mastitis model. Mice infected with two different NT S. aureus strains with strong and weak biofilm forming potential demonstrated identical clinical symptoms (moderate), minimal inflammatory infiltrates, and tissue damage (level 1 histopathological changes) in the mammary glands. However, the S. aureus load in the mammary glands of mice and the level of pro-inflammatory cytokines (IL-1β, IL-6, IL-12, IL-17 and IFN-γ) in serum were significantly higher (p ≤ 0.05) in those infected with the strong biofilm forming NT S. aureus strain. The level of IL-6 in sera samples of these mice was extremely high (15,479.9 ± 532 Pg/mL). Furthermore, these mice died in 24h of post infection compared to 30 h in the weak biofilm forming NT S. aureus infected group. The study demonstrates no association between the strength of PIA (polysaccharide intercellular adhesion)-dependent biofilm production by clinical NT S. aureus and mammary gland pathology in a mouse mastitis model. However, the role of biofilm in the virulence of S. aureus advancing the time of mortality in mice warrants further investigation.
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Mirzaei B, Babaei R, Zeighami H, Dadar M, Soltani A. Staphylococcus aureus Putative Vaccines Based on the Virulence Factors: A Mini-Review. Front Microbiol 2021; 12:704247. [PMID: 34539603 PMCID: PMC8447878 DOI: 10.3389/fmicb.2021.704247] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Accepted: 07/30/2021] [Indexed: 12/25/2022] Open
Abstract
Since the 1960s, the frequency of methicillin-resistant Staphylococcus aureus as a recurrent cause of nosocomial infections has increased. Since multidrug-resistant Staphylococcus has overcome antimicrobial treatment, the development of putative vaccines based on virulence factors could be a great help in controlling the infections caused by bacteria and are actively being pursued in healthcare settings. This mini-review provides an overview of the recent progress in vaccine development, immunogenicity, and therapeutic features of some S. aureus macromolecules as putative vaccine candidates and their implications against human S. aureus-related infections. Based on the reviewed experiments, multivalent vaccines could prevent the promotion of the diseases caused by this bacterium and enhance the prevention chance of S. aureus infections.
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Affiliation(s)
- Bahman Mirzaei
- Department of Medical Microbiology and Virology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Ryhaneh Babaei
- Department of Medical Microbiology and Virology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Habib Zeighami
- Department of Medical Microbiology and Virology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
| | - Maryam Dadar
- Razi Vaccine and Serum Research Institute, Agricultural Research, Education and Extension Organization, Karaj, Iran
| | - Ali Soltani
- Department of English Language, Zanjan University of Medical Sciences, Zanjan, Iran
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Abstract
The number and frequency of multidrug-resistant (MDR) strains as a frequent cause of nosocomial infections have increased, especially for Methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis, in part due to device-related infections. The transition to antibiotic-resistance in related bacterial genes and the capability for immune escape have increased the sustainability of biofilms produced by these bacteria. The formation and changes in biofilms have been suggested as a target to prevent or treat staphylococcal infections. Thus, this study reviews the development of candidate staphylococcal vaccines by database searching, and evaluates the immunogenicity and efficacy profiles of bacterial components involved in biofilms. The literature suggests that using common staphylococcal vaccine antigens and multivalent vaccines should further enhance vaccine efficacy.
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Affiliation(s)
- Bahman Mirzaei
- Department of Medical Microbiology and Virology, Faculty of Medicine, Mazandaran University of Medical Sciences , Sari, Iran.,Department of Medical Microbiology and Virology, School of Medicine, Zanjan University of Medical Science , Zanjan, Iran
| | - Ryhaneh Babaei
- Department of Medical Microbiology and Virology, School of Medicine, Zanjan University of Medical Science , Zanjan, Iran
| | - Sina Valinejad
- Department of Medical Microbiology and Virology, School of Medicine, Zanjan University of Medical Science , Zanjan, Iran
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Yan G, Li H, Zhao W, Shi Z. Evaluation of thermal indices based on their relationships with some physiological responses of housed lactating cows under heat stress. Int J Biometeorol 2020; 64:2077-2091. [PMID: 32851452 DOI: 10.1007/s00484-020-01999-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 07/03/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Thermal indices as environmental risk indicators have been used to assess heat stress of dairy cows. The present study aimed to evaluate the predictive performance of the typical cattle-related thermal indices by comparing their prediction to heat stress levels and associations with some physiological responses. The study was conducted from August to September 2019 in a naturally ventilated barn in Jiangsu, China. Nine typical cattle-related thermal indices, i.e., temperature-humidity index (THI), black globe temperature index (BGHI), equivalent temperature index, effective temperature (ET) for dairy cows, respiratory rate predictor (RRP), adjusted temperature-humidity index (THIadj), heat load index (HLI), comprehensive climate index (CCI), and equivalent temperature index for cattle (ETIC), were evaluated. Respiration rate (RR) and body surface temperature (BST) were collected twice per day from a total of 287 lactating cows, 18 of which were continuously measured vaginal temperature (VT). Over the experimental period, the average daily RR, VT, and BST were 55.8 breaths/min, 38.7 °C, and 32.3 to 36.4 °C that depend on body positions, respectively. The study found that the prediction of THI, BGHI, THIadj, and CCI was closer to the actual heat stress conditions which were mild to moderate heat stress. Correlation analyses showed that RR, VT, and BST correlated most closely with effective temperature (r = 0.580; P < 0.05), BGHI (r = 0.642; P < 0.05), and CCI (r = 0.849; P < 0.05). In this evaluation, based on the comprehensive performance of CCI in the relatively accurate prediction to heat stress level and duration, detection on environmental differences between standing and lying zone, and correlations with some physiological responses, CCI is seemingly the promising thermal index to assess heat stress of housed dairy cows.
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Affiliation(s)
- Geqi Yan
- College of Water Resources and Civil Engineering, China Agricultural University, 17 Tsing Hua East Road, Beijing, 100083, China
| | - Hao Li
- College of Water Resources and Civil Engineering, China Agricultural University, 17 Tsing Hua East Road, Beijing, 100083, China
| | - Wanying Zhao
- College of Water Resources and Civil Engineering, China Agricultural University, 17 Tsing Hua East Road, Beijing, 100083, China
| | - Zhengxiang Shi
- College of Water Resources and Civil Engineering, China Agricultural University, 17 Tsing Hua East Road, Beijing, 100083, China.
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Ambroggio MB, Perrig MS, Camussone C, Pujato N, Bertón A, Gianneechini E, Alvarez S, Marcipar IS, Calvinho LF, Barbagelata MS. Survey of potential factors involved in the low frequency of CP5 and CP8 expression in Staphylococcus aureus isolates from mastitis of dairy cattle from Argentina, Chile, and Uruguay. J Appl Genet 2018; 59:357-63. [DOI: 10.1007/s13353-018-0443-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Revised: 02/20/2018] [Accepted: 04/10/2018] [Indexed: 12/20/2022]
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Gogoi-Tiwari J, Babra Waryah C, Sunagar R, Veeresh HB, Nuthanalakshmi V, Preethirani PL, Sharada R, Isloor S, Bhat A, Al-Salami H, Hegde NR, Mukkur TK. Typing ofStaphylococcus aureusisolated from bovine mastitis cases in Australia and India. Aust Vet J 2015. [DOI: 10.1111/avj.12349] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- J Gogoi-Tiwari
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin University; Perth Western Australia Australia
| | - C Babra Waryah
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin University; Perth Western Australia Australia
| | - R Sunagar
- Ella Foundation; Genome Valley, Shameerpet Mandal Hyderabad India
| | - HB Veeresh
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - V Nuthanalakshmi
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - PL Preethirani
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - R Sharada
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - S Isloor
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - A Bhat
- Veterinary College; Karnataka Veterinary, Animal and Fisheries Sciences University; Hebbal Bangalore India
| | - H Al-Salami
- School of Pharmacy, Faculty of Health Sciences; Curtin University; Perth Western Australia Australia
| | - NR Hegde
- Ella Foundation; Genome Valley, Shameerpet Mandal Hyderabad India
| | - TK Mukkur
- School of Biomedical Sciences, Faculty of Health Sciences; Curtin University; Perth Western Australia Australia
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Scali F, Camussone C, Calvinho L, Cipolla M, Zecconi A. Which are important targets in development of S. aureus mastitis vaccine? Res Vet Sci 2015; 100:88-99. [DOI: 10.1016/j.rvsc.2015.03.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2014] [Revised: 03/04/2015] [Accepted: 03/14/2015] [Indexed: 12/21/2022]
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Broughan J, Anderson R, Anderson AS. Strategies for and advances in the development ofStaphylococcus aureusprophylactic vaccines. Expert Rev Vaccines 2014; 10:695-708. [DOI: 10.1586/erv.11.54] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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Babra C, Tiwari JG, Pier G, Thein TH, Sunagar R, Sundareshan S, Isloor S, Hegde NR, de Wet S, Deighton M, Gibson J, Costantino P, Wetherall J, Mukkur T. The persistence of biofilm-associated antibiotic resistance of Staphylococcus aureus isolated from clinical bovine mastitis cases in Australia. Folia Microbiol (Praha) 2013; 58:469-74. [DOI: 10.1007/s12223-013-0232-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2012] [Accepted: 02/13/2013] [Indexed: 10/27/2022]
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Camussone CM, Calvinho LF. Factores de virulencia de Staphylococcus aureus asociados con infecciones mamarias en bovinos: relevancia y rol como agentes inmunógenos. Rev Argent Microbiol 2013; 45:119-130. [DOI: 10.1016/s0325-7541(13)70011-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Camussone CM, Veaute CM, Porporatto C, Morein B, Marcipar IS, Calvinho LF. Immune response of heifers against a Staphylococcus aureus CP5 whole cell vaccine formulated with ISCOMATRIX™ adjuvant. J DAIRY RES 2013; 80:72-80. [PMID: 23171590 DOI: 10.1017/S0022029912000593] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The shortcomings of Staphylococcus aureus vaccines to control bovine mastitis have been attributed to insufficient capacity of the vaccines to induce opsonizing antibodies and to stimulate cellular immune responses. Types of antigen, administration route and adjuvant used in a vaccine formulation have been identified as critical factors for the development of opsonic antibodies. Current commercially available vaccines for Staph. aureus bovine mastitis control are formulated with Al(OH)3 and oil-based adjuvants. The aim of this study was to evaluate the immune response of heifers immunized with a Staph. aureus CP5 whole cell vaccine formulated either with Al(OH)3 or ISCOMATRIX™. Twenty primigravid Holstein dairy heifers in the last trimester of gestation were immunized either with a vaccine formulated with ISCOMATRIX™ (n = 6), Al(OH)3 (n = 7), or saline solution (placebo) (n = 7). Immunization was carried out 38 and 10 d before calving. Heifers vaccinated with Staph. aureus adjuvanted with ISCOMATRIX™ responded with significantly higher levels of anti-bacterin and anti-CP5 IgG and IgG2 in sera than animals in the Al(OH)3 or control groups. Animals in the ISCOMATRIX™ group responded with significantly higher anti-bacterin specific IgG in whey than animals in the Al(OH)3 and control groups, detected from the first week post calving until 60 d of lactation. Sera from animals inoculated with Staph. aureus in ISCOMATRIX™, obtained 7 d post partum, significantly increased both the number of neutrophils ingesting bacteria and the number of bacteria being ingested by the neutrophils, compared with sera obtained from heifers vaccinated with Al(OH)3 or non-vaccinated controls. These features coupled to safety of the ISCOMATRIX™ formulation, warrant additional studies.
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Wang LH, Li XY, Jin LJ, You JS, Zhou Y, Li SY, Xu YP. Characterization of chicken egg yolk immunoglobulins (IgYs) specific for the most prevalent capsular serotypes of mastitis-causing Staphylococcus aureus. Vet Microbiol 2011; 149:415-21. [DOI: 10.1016/j.vetmic.2010.11.029] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2010] [Revised: 11/16/2010] [Accepted: 11/19/2010] [Indexed: 11/17/2022]
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Vakanjac S, Pavlovic M, Pavlovic V. Testing the efficiency of different treatments of subclinical Staphylococcus aureus mastitis in cows during the dry period. ACTA VET-BEOGRAD 2010; 60:227-239. [DOI: 10.2298/avb1003227v] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
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Tuchscherr LPN, Gomez MI, Buzzola FR, Calvinho LF, Lee JC, Sordelli DO. Characterization of a new variant of IS257 that has displaced the capsule genes within bovine isolates of Staphylococcus aureus. Infect Immun 2007; 75:5483-8. [PMID: 17785471 PMCID: PMC2168288 DOI: 10.1128/iai.00747-07] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many bovine Staphylococcus aureus isolates from Argentina are nontypeable (NT), i.e., they do not produce serotype 5 or 8 capsular polysaccharides (CPs). Some of these NT strains have a deletion of the cap5(8) gene cluster mediated by a variant of IS257, now designated IScap. IScap showed 93% amino acid identity to S. aureus ORF49 but only 85% identity to IS431 from S. aureus N315 and 88% identity to an IS257-like element from bovine strain RF122. Thirty-six (53%) of 68 bovine isolates, drawn from a previously described S. aureus strain collection, carried some variant of IS257, including IScap. Of these 36 IS+ isolates, 6 were CP5+, 1 was CP8+, and 29 were NT. Forty-four of the 68 isolates were NT, and 24 of these 44 NT isolates (55%) exhibited IScap-mediated deletion of the cap5(8) gene cluster. IScap was not found among 20 human NT S. aureus isolates bearing the cap5HIJK genes, which suggests that IScap-mediated deletion of the capsule locus is restricted to bovine strains of S. aureus. We were unable to identify a precursor strain in which IScap flanked the cap5(8) capsule locus, nor were we able to select for deletion of the cap5(8) locus in vitro. Our results support the hypothesis that deletion of the cap5 locus occurred in the distant past and that the relative abundance of these NT strains may be a result of their ability to persist in subclinical mastitis infection in cows.
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Affiliation(s)
- L P N Tuchscherr
- Department of Microbiology, School of Medicine, University of Buenos Aires, Paraguay 2155 P-12, C1121ABG Buenos Aires, Argentina
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Jones C. Revised structures for the capsular polysaccharides from Staphylococcus aureus Types 5 and 8, components of novel glycoconjugate vaccines. Carbohydr Res 2005; 340:1097-106. [PMID: 15797125 DOI: 10.1016/j.carres.2005.02.001] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Revised: 01/31/2005] [Accepted: 02/02/2005] [Indexed: 11/15/2022]
Abstract
Glycoconjugate vaccines based on the capsular polysaccharides (CPSs) from Staphylococcus aureus serotypes 5 and 8 conjugated to genetically detoxified recombinant exoprotein A (rEPA) from Pseudomonas aeruginosa have been shown, in Phase 3 clinical trials, to elicit a strong bactericidal immune response in end-stage renal disease patients. Such vaccines have the potential to reduce morbidity and mortality due to methicillin-resistant Staphylococcus aureus (MRSA), a major cause of hospital-acquired infection. The serotype 5 and 8 polysaccharides have been fully characterized by NMR spectroscopy and full structural analyses carried out. Published structures were found incorrect and the revised structures of the repeat units of the two polysaccharides are: [carbohydrate structure: see text]. Resonances indicative of the presence of peptidoglycan were observed in the spectra of both CPSs, consistent with reports that the CPS is covalently linked to peptidoglycan.
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Affiliation(s)
- Christopher Jones
- Laboratory for Molecular Structure, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Herts EN6 3QG, UK.
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