Majority Of Methicillin-resistant Staphylococcus Aureus Research Articles

Investigation and mapping of the prevalence of “superbugs” Methicillin-resistant Staphylococcus aureus (MRSA) and antimicrobial susceptibility pattern in Enugu metropolis in Southeast Nigeria

Global public health is threatened by increasing incidence of Antimicrobial resistance (AMR). Methicillin-Resistant Staphylococcus aureus (MRSA), usually referred to as “superbug, is a prominent AMR that is generating concerns across the world. They are resistant to commonly used antibiotics, thereby making treatment of common infections very difficult; resulting in prolonged illness and hospitalisation, disability and in some cases, death. Despite the concerns and threats posed by MRSA, studies of its prevalence in communities across Nigeria are scanty. Here, we investigated the prevalence of MRSA in the South East Nigeria using isolates obtained from two major hospitals in Enugu metropolis and a medical laboratory. The isolates were clinically identified from different specimens and pure isolates were subjected to antimicrobial susceptibility profiling using conventional antibiotics. Geographic Information System (GIS) techniques were used to analyse the anonymised three year MRSA records. This provided relevant insights on the spatial spread of MRSA in the city. This research serves as a first step towards modelling its spatial epidemiology in the region. Results indicated that cases of MRSA were widespread in the city. Majority of MRSA were resistant to the antibiotics indicating that they are multidrug-resistant (MDR). Spatiotemporal analyses conducted showed that incidence of MRSA was increasing by the year.

Prevalence of MRSA and Antimicrobial Susceptibility Staphylococcus aureus in Clinical Samples in National Capital Region, India

Background: Infections caused by Staphylococci are frequently linked to indwelling medical equipment. These are extremely difficult to treat with antibiotics. In India, the prevalence of Methicillin-Resistant Staphylococcus aureus (MRSA) varies from 30 to 70%, resulting in high mortality, increased economic burden, and high treatment failure in tertiary care hospitals. Rapid and reliable identification of MRSA is critical for infection management and avoiding the needless use of antibiotics.
 Materials and Methods: This prospective study was carried out in the Department of Microbiology, Santosh Medical College, Ghaziabad, from the 1st of August 2020 to the 31st of January 2021. MRSA isolates were screened and confirmed using standard methods recommended by the Clinical and Laboratory Standards Institute (CLSI). Methicillin resistance, in Staphylococcus aureus strains, was evaluated using oxacillin/cefoxitin. The Kirby-Bauer disc diffusion technique was used to assess the antibiotic susceptibility pattern of all MRSA strains.
 Results: In this investigation, MRSA was identified in 29.4% of the 384 Staphylococcus aureus strains. When compared to females, men outnumbered females. Cefoxitin detects a greater amount of MRSA than oxacillin. In this investigation, the majority of MRSA was found in pus samples.
 Conclusion: MRSA prevalence is known to vary depending on geographical region, hospital type, investigated population, and technique of detection used. Given the clinical implications of MRSA infection and its fast transmission capability, MRSA strains must be monitored on a regular basis.

MRSA and multidrug-resistant Staphylococcus aureus in U.S. retail meats, 2010–2011

Methicillin-resistant Staphylococcus aureus (MRSA) has been detected in retail meats, although large-scale studies are scarce. We conducted a one-year survey in 2010–2011 within the framework of the National Antimicrobial Resistance Monitoring System. Among 3520 retail meats collected from eight U.S. states, 982 (27.9%) contained S. aureus and 66 (1.9%) were positive for MRSA. Approximately 10.4% (107/1032) of S. aureus isolates, including 37.2% (29/78) of MRSA, were multidrug-resistant (MDRSA). Turkey had the highest MRSA prevalence (3.5%), followed by pork (1.9%), beef (1.7%), and chicken (0.3%). Whole-genome sequencing was performed for all 66 non-redundant MRSA. Among five multilocus sequence types identified, ST8 (72.7%) and ST5 (22.7%) were most common and livestock-associated MRSA ST398 was assigned to one pork isolate. Eleven spa types were represented, predominately t008 (43.9%) and t2031 (22.7%). All four types of meats harbored t008, whereas t2031 was recovered from turkey only. The majority of MRSA (84.8%) possessed SCCmec IV and 62.1% harbored Panton-Valentine leukocidin. Pulsed-field gel electrophoresis showed that all ST8 MRSA belonged to the predominant human epidemic clone USA300, and others included USA100 and USA200. We conclude that a diverse MRSA population was present in U.S. retail meats, albeit at low prevalence.

Transmission of methicillin-resistant Staphylococcus aureus in long-term care facilities and their related healthcare networks.

BackgroundLong-term care facilities (LTCF) are potential reservoirs for methicillin-resistant Staphylococcus aureus (MRSA), control of which may reduce MRSA transmission and infection elsewhere in the healthcare system. Whole-genome sequencing (WGS) has been used successfully to understand MRSA epidemiology and transmission in hospitals and has the potential to identify transmission between these and LTCF.MethodsTwo prospective observational studies of MRSA carriage were conducted in LTCF in England and Ireland. MRSA isolates were whole-genome sequenced and analyzed using established methods. Genomic data were available for MRSA isolated in the local healthcare systems (isolates submitted by hospitals and general practitioners).ResultsWe sequenced a total of 181 MRSA isolates from the two study sites. The majority of MRSA were multilocus sequence type (ST)22. WGS identified one likely transmission event between residents in the English LTCF and three putative transmission events in the Irish LTCF. WGS also identified closely related isolates present in colonized Irish residents and their immediate environment. Based on phylogenetic reconstruction, closely related MRSA clades were identified between the LTCF and their healthcare referral network, together with putative MRSA acquisition by LTCF residents during hospital admission.ConclusionsThese data confirm that MRSA is transmitted between residents of LTCF and is both acquired and transmitted to others in referral hospitals and beyond. Our data present compelling evidence for the importance of environmental contamination in MRSA transmission, reinforcing the importance of environmental cleaning. The use of WGS in this study highlights the need to consider infection control in hospitals and community healthcare facilities as a continuum.Electronic supplementary materialThe online version of this article (doi:10.1186/s13073-016-0353-5) contains supplementary material, which is available to authorized users.

Threat of multidrug resistant Staphylococcus aureus in Western Nepal

ObjectiveTo determine the prevalence of methicillin resistant Staphylococcus aureus (MRSA) and antimicrobial susceptibility patterns of the isolates from Manipal Teaching Hospital, Pokhara, Nepal. MethodsThis study was conducted over a period of 11 months (September 2012–August 2013) at the Manipal Teaching Hospital, Pokhara, Nepal. A total of 400 isolates were collected from various clinical specimens including hospital units (operation theaters and intensive care units). Antibiotic susceptibility testing was performed by Kirby-Bauer disc diffusion method. Primary screening for MRSA was performed using disc diffusion test by cefoxitin (30 μg) and oxacillin (1 μg) disc, further confirmation was done by detection of mecA gene using PCR. ResultsOut of 400 Staphylococcus aureus strains, 139 (34.75%) were found to be MRSA. Among the MRSA isolates, 74 (53.2%) were from inpatient departments, 58 (41.7%) of the isolates were from outpatients and 7 (5.0%) isolates were from hospital units (operation theaters and intensive care units). Majority of MRSA (73.38%) isolates were multidrug resistant while less than 15% were resistant to amikacin, clindamycin and tetracycline. None of the isolate was resistant to vancomycin. Inducible clindamycin resistance was found in 54 (25.47%) isolates. ConclusionsThis study showed a high prevalence of MRSA in our hospital. There is need of regular surveillance of antibiotic resistance, standardization of laboratory methods for detecting methicillin resistance and performing antibiotic susceptibility testing in developing countries like Nepal. Hospital acquired infections including prevalence of MRSA can be minimized by appropriate hygienic measures in patient care and management and by antibiotic stewardship. Screening of erythromycin resistant isolates would minimize clinical failures associated with clindamycin therapy.

Staphylococcus aureus nasal carriage among healthcare workers in Kisangani, the Democratic Republic of the Congo.

Methicillin-resistant Staphylococcus aureus (MRSA) is a global health concern, but there are few data from Central Africa. The objective of our study was to characterise S. aureus colonisation isolates from healthcare-exposed professionals in the Democratic Republic of the Congo (DRC). Healthcare workers and medical students (n = 380) in Kisangani, DRC were screened for S. aureus nasal carriage in a single-centre cross-sectional study in the University Hospital of Kisangani. The isolates were identified and characterised using phenotypic and genotypic methods. The nasal carriage rate of S. aureus was 16.6% and 10 out of 63 isolates (15.9%) were MRSA. We found 28 different spa types. Most MRSA isolates belonged to ST8-spa t1476-SCCmec V. The majority of MRSA were multidrug-resistant to non-beta-lactam antibiotics. Overall, 28.5% of S. aureus carried Panton-Valentine leucocidin (PVL)-encoding genes (all methicillin-sensitive) and 17.5% carried toxic shock syndrome toxin-1 (TSST-1)-encoding genes. The finding of MRSA carriage among healthcare workers in a setting with limited access to diagnostic microbiology and appropriate therapy calls for improved education on infection control practices and supports the introduction of surveillance programmes.

Antibiogram of Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus in patients with diabetes.

To determine the antibiogram of Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus (MRSA) in patients with diabetes. The study was carried out in the Microbiology Department of Clinical and Research Laboratory, Baqai Institute of Diabetology and Endocrinology (BIDE) from January 2012 to December 2012. All samples received in the laboratory were processed according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Identification of Pseudomonas aeruginosa and Methicillin-resistant Staphylococcus aureus (MRSA) was done and antimicrobial susceptibility pattern was determined by disc diffusion method. A total of 585 pathogens were isolated from 542 specimens of patients with diabetes. One hundred twenty one (20.68%) Pseudomonas aeruginosa and 25(4.27%) non-aeruginosa Pseudomonas were detected from 542 samples. Among 108 (18%) samples detecting the growth of Staphylococcus aureus, Methicillin-resistant Staphylococcus aureus (MRSA) were found in 42 (39%) samples. Pseudomonas aeruginosa showed marked susceptibility to imipenem (100%) followed by piperacillin / tazobactam (90.91%). All MRSA positive specimens were susceptible to vancomycin, but highly or completely resistant to the other antimicrobial drugs. Conclusion : In the present study imipenem, piperacillin/tazobactam and sulbactam-cefoperazone were found to be the most effective drugs against Pseudomonas aeruginosa. The majority of MRSA were resistant to one or more than one antimicrobial drugs. Vancomycin and imipenem were the most effective drugsagainstStaphylococcus aureus and MRSA. .

Susceptibility of Methicillin-resistant Staphylococci Clinical Isolates to Netilmicin and Other Antibiotics Commonly Used in Ophthalmic Therapy

Purpose: The aim of this study was to test the activity of selected antimicrobial agents commonly used in the treatment of ocular infections against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus epidermidis (MRSE) isolates.Methods: A total of 43 staphylococci from respiratory tract and ocular infections were characterized for methicillin resistance using the Epsilometer test (E-test), the polymerase chain reaction for mecA gene detection and the PBP2′ latex agglutination test. A perfect agreement among them was observed in 20 isolates (8 MRSA and 12 MRSE) which were then employed in the susceptibility test by using the agar disk diffusion test (NCCLS). The antibiotics tested were: netilmicin (NET), tobramycin (TOB), azithromycin (AZM), levofloxacin (LEV), moxifloxacin (MXF), chloramphenicol (C) and vancomycin (VA).Results: All MRSE and most (87.5%) of MRSA isolates tested were NET and VA sensitive. The majority of MRSA were found to be resistant to all the other antibiotics, with the exception of C. In particular, 75%, 87% and 100% of the isolates were resistant to fluoroquinolones (LEV and MXF), AZM and TOB, respectively. As for the MRSE group, 25% of the strains tested were resistant to C and MXF while 33%, 42% and 58% of the strains were resistant to LEV, AZM and TOB, respectively.Conclusions: Together with VA, NET was the most effective antibiotic tested against both MRSA and MRSE clinical isolates. The exclusive topical use of NET for the treatment of ocular infections may curtail the emergence, spreading and persistence of antibiotic-resistant bacteria.

Methicillin-resistant Staphylococcus aureus detection using chromogenic media: the Sheffield experience

Methicillin-resistant Staphylococcus aureus (MRSA) continues to cause major problems, both in hospitals and the community. Microbiology departments need to review their methodology regularly to ensure that they are contributing in the most appropriate manner to the battle against MRSA. Media employing chromogenic enzymes to aid the isolation and identification of MRSA is a relatively new approach. In this study, 192 swabs from 112 different patients were inoculated on two chromogen-containing media and four other commonly used solid MRSA media to determine which gave the appropriate combination of sensititivity, specificity and speed of result. Methicillin-resistant S. aureus was isolated on at least one of the six media from 102 of the 192 swabs. Both chromogenic media proved to be statistically significantly more sensitive than the other media after overnight incubation and had a sensitivity of 96% after 48 hours’ incubation. The recent introduction of chromogen-containing MRSA media offers microbiology laboratories the opportunity to isolate and confirm the majority of MRSA infections/colonisations in 24 hours, which should result in better patient care. The possible slight increase in costs should not provide a valid excuse for using inferior methodologies.

National prevalence of methicillin-resistant Staphylococcus aureus in inpatients at US health care facilities, 2006

Despite methicillin-resistant Staphylococcus aureus (MRSA) being endemic in virtually all US health care facilities, there are no data on the prevalence of MRSA in US health care facilities. We conducted a national prevalence survey of MRSA in inpatients at US health care facilities. The survey was developed, received institutional review board approval, and then distributed to all members of the Association for Professionals in Infection Control and Epidemiology, Inc. (APIC). Members were asked to complete the survey on one day during the period October 1 to November 16, 2006, reporting the number of inpatients with MRSA infection or colonization and facility-specific information. Personnel at 1237 hospitals completed the survey. Complete facility data were provided for 1187 (96%) of these health care facilities. All states were represented (mean, 23 facilities per state; range, 1-99). Respondents reported 8654 MRSA-colonized/infected patients in 187,058 inpatients; the overall MRSA prevalence rate was 46.3 per 1000 inpatients (34 infections and 12 colonizations per 1000 inpatients). Active MRSA surveillance testing was conducted by 29% of respondents: 54% used routine media, 38% used selective media, and 8% used polymerase chain reaction. Detailed data were provided on 7994 (92.4%) MRSA-colonized/infected patients. Our data suggest that approximately 70% of isolates were more consistent with health care-associated MRSA (HA-MRSA) than community-associated MRSA. Our survey documents a much higher MRSA prevalence rate than previous studies using different methodologies. The majority of MRSA in inpatients appears to be HA-MRSA. Given that most facilities did not perform active surveillance testing, these are minimum estimates of the national burden of MRSA in US health care facilities.

Methicillin-resistant Staphylococcus aureus (MRSA) isolated from small and exotic animals at a university hospital during routine microbiological examinations

Clinical specimens of small animals ( n = 869) were screened for the occurrence of methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA; MRSA) during routine microbiological examinations, and results were confirmed by a multiplex PCR strategy. The genetic relatedness of all mecA-positive S. aureus isolates was further investigated by pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), PCR for Panton-Valentine leukocidine genes (PVL) and staphylococcal cassette chromosome mec-typing (SCC mec). A total of 61 S. aureus isolates were found during a 20-month period of investigation, 27 (44.3%) of them harbouring the mecA gene for methicillin-resistance. The majority of MRSA were isolated in specimens from dogs ( n = 18) and cats ( n = 4). One guinea pig and one rabbit were found to be positive for an MRSA infected site. Similarly, three exotic animals, a turtle, a bat and a parrot, were found to be infected with MRSA. PFGE and MLST analysis revealed a certain genotype (“A” and “A-1”) dominating the isolate collection (23 of 27). Furthermore, one isolate showed homologous PFGE pattern to the German epidemic strain Barnim (“BE”) and another one (“BE-1”) was considered to be closely related. A third genotype (“B”) was detected in two cases. Two different sequence types (ST) were identified among the 27 MRSA isolates. PFGE type “A” and both strains related to the Barnim epidemic strain were assigned to ST22, whereas ST239 was associated to PFGE profile “B”. The present data show that certain MRSA genotypes are capable of infecting a wide spectrum of small and exotic animals, especially in clinical facilities.