High Prevalence Of Methicillin-resistant Staphylococcus Aureus Research Articles

Multifaceted aseptic protocol decreases surgical site infections following hip arthroplasty

We investigate the effectiveness of a comprehensive aseptic protocol in reducing surgical site infection (SSI) after hip arthroplasty in a single medical centre with a high prevalence of methicillin-resistant Staphylococcus aureus (MRSA). A prospectively collected database of all patients undergoing hip arthroplasty in a single centre between 2005 and 2011 was reviewed for SSI using Centers for Disease Control (CDC) criteria and AAOS guidelines. All patients were administered an aseptic protocol consisting of: preoperative 2% mupirocin nasal ointment and 0.4% chlorhexidine surgical-site wipes; modified instrument care; perioperative prophylactic vancomycin and cefazolin; and surgical-site skin preparation with chlorhexidine, alcohol and iodophor. We compare our protocol hip arthroplasty SSI rate to our institutional historical control and to contemporary literature. Among 774 patients, 69% were ASA>2, 45% had BMI≥30 and 10.3% had rheumatoid arthritis. We found an overall 0.39% infection rate; significantly lower than our institutional historical control (0.39% vs. 2.60%, p<0.001, OR 0.15, NNT 200) and significantly lower than 6 published reports (p<0.001-0.022, OR 0.16-0.22). Compared to these cohorts, significantly more of our patients were ASA>2, had BMI≥30 or had rheumatoid arthritis. Patients with 3 or more identifiable risk factors were at an increased risk of SSI compared to those with 2 or fewer risk factors. Our aseptic protocol decreases SSI in a high-risk population undergoing hip arthroplasty in a medical centre and community with a high prevalence of MRSA.

Bacterial pathogens associated with external ocular infections alongside eminent proportion of multidrug resistant isolates at the University of Gondar Hospital, northwest Ethiopia

BackgroundExternal ocular infection is a public health problem in Ethiopia. The aim of this study was to determine the prevalence and antimicrobial susceptibility pattern of external ocular bacterial infections.MethodsA cross sectional study was conducted at the University of Gondar Hospital among patients seeking health services at the Department of Ophthalmology from January to April, 2016. All patients with suspected external ocular infections were examined under slit lamp microscope. External ocular samples were collected using aseptic techniques. All samples were investigated by culture and bacteria were identified using standard methods. Drug susceptibility test was done using the Kirby-Bauer Disk diffusion method according to the guidelines of Clinical and Laboratory Standard Institute (CLSI).ResultA total of 312 samples were collected and 58.3% were culture positive. The proportion of Gram positive bacterial pathogens was (88%), and Staphylococcus aureus (50.3%) was the predominantly isolated pathogen, followed by Coagulase negative staphylococci (CoNS) (33.5%) and Klebsiella species (4.7%). Conjunctivitis was the dominant clinical feature, but a high positive result for bacterial pathogens was observed among patients with dacryocystitis cases. The Gram positive bacterial isolates were susceptible to ciprofloxacin, chloramphinicol, amoxicillin-clavulanate and ceftriaxone. However, 65% of these Gram positive bacterial pathogens showed resistance to penicillin, ampicillin and amoxicillin. The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) infection was 24% and multidrug resistance (MDR) was observed in 87% of the isolated bacteria.ConclusionConjunctivitis was the dominant ophthalmic disease followed by blepharitis. The dominant bacteria species was S. aureus and MRSA infection is increasingly prevalent. The overall MDR bacterial pathogen proportion was very high. The high prevalence of MRSA and MDR bacterial pathogens dictate the need for effective prevention as important as for therapies.

High prevalence of MRSA and ESBL among asylum seekers in the Netherlands

Migration is one of the risk factors for the spread of multidrug-resistant organisms (MDRO). The increasing influx of migrants challenges local health care systems. To provide evidence for both hospital hygiene measure and empirical antibiotic therapy, we analysed all cultures performed in asylum seekers between January 1st 2014 and December 31st 2015 for methicillin resistant Staphylococcus aureus (MRSA) and for multidrug-resistant Enterobacteriaceae (MDRE). We compared these with cultures from the Dutch patient population with risk factors for carriage of MDRO. A total of 7181 patients were screened for MRSA. 7357 S. aureus were isolated in clinical cultures. Of 898 screened asylum seekers, almost 10% were MRSA positive. Of 118 asylum seekers with S. aureus in clinical cultures almost 19% were MRSA positive. The general patient population had a 1.3% rate of MRSA in S. aureus isolates. A higher rate of Panton-Valentine leukocidin (PVL) positive strains (RR: 2.4; 95% CI: 1.6–3.4) was found in asylum seekers compared to the general patient population. In 33475 patients one or more Enterobacteriaceae were obtained. More than 21% of the asylum seekers were carrier of MDRE, most of them producing extended spectrum beta-lactamases (20.3%). 5.1% of the general patient population was MDRE carrier. It can be concluded that asylum seekers present with higher rate of MDRO compared to the general patient population. These results justify continued screening of asylum seekers to anticipate multidrug-resistant organisms during hospital care of patients.

Antibiotic resistance in the Western Pacific Region: a systematic review

Purpose: There have been increasing reports of bacteria carrying antibiotic-resistant genes discovered in the Western Pacific Region (WPR) in recent years. However, the impact on human health of these resistant pathogens has not been well documented due to the lack of region-wide and national surveillance programs on antimicrobial resistance (AMR) in the region. The objective of this review is to systematically review published evidence on the prevalence of AMR in selected bacterial pathogens in the region over the past 15 years. Methods & Materials: A literature search for published data on AMR in eight selected pathogens (methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli, Enterococcus faecalis, Haemophilus influenzae, Klebsiella pneumoniae, Neisseria gonorrhoeae, Pseudomonas aeruginosa, and Streptococcus pneumoniae) was conducted on bibliographic database PubMed for five pre-selected locations in the WPR, namely mainland China, Japan, Australia, the Republic of Korea and Hong Kong. Results: Our search identified 4,674 articles, 207 of which reported the prevalence of the eight selected pathogens in the five pre-selected locations. There were 43 studies on E. coli, 41 on MRSA, 25 on K. pneumoniae, 25 on N. gonorrhoeae, 24 on P. aeruginosa, 24 on S. pneumoniae, 15 on H. influenza, and 10 on E. faecalis. In the five selected locations, greatest levels of resistance were reported for E. coli (33.7% - 93.3% against ampicillin) and S. pneumoniae (4.1% - 97% against erythromycin). High prevalence of MRSA was recorded in the region over the past 15 years (up to 73% in Korea, 69% in Hong Kong, 64.8% in China, and 63.4% in Japan), with the exception of Australia (16% - 30.3%). Moderate to high levels of resistance against third-generation cephalosporins were reported in P. aeruginosa, and high levels of resistance against penicillin and fluoroquinolones were also reported in N. gonorrhoeae. Conclusion: Generally, high prevalences of antibiotic resistance were identified in the 5 selected locations in the WPR, particularly in E. coli, N. gonorrhoeae, P. aeruginosa, and S. pneumoniae. However, longitudinal trends of antibiotic resistance in any of the selected pathogens were difficult to determine as most published data were generated from cross-sectional studies and few were from systematic surveillance through national or region-wide networks.

Prevalence of Nasal Colonization by Methicillin-Resistant Staphylococcus aureus in Persons Using a Homeless Shelter in Kansas City.

Nasal colonization of methicillin-resistant Staphylococcus aureus (MRSA) plays an important role in the epidemiology and pathogenesis of disease. Situations of close-quarter contact in groups are generally regarded as a risk factor for community-acquired MRSA strains due to transmission via fomites and person-to-person contact. With these criteria for risk, homeless individuals using shelter facilities, including showers and toilets, should be considered high risk for colonization and infection. The aim of this study was to determine the prevalence of nasal colonization of MRSA in a homeless population compared to established rates of colonization within the public and a control group of subjects from a neighboring medical school campus, and to analyze phylogenetic diversity among the MRSA strains. Nasal samples were taken from the study population of 332 adult participants and analyzed. In addition, participants were surveyed about various lifestyle factors in order to elucidate potential patterns of behavior associated with MRSA colonization. Homeless and control groups both had higher prevalence of MRSA (9.8 and 10.6%, respectively), when compared to the general population reported by previous studies (1.8%). However, the control group had a similar MRSA rate compared to health-care workers (4.6%), while the homeless population had an increased prevalence. Risk factors identified in this study included male gender, age over 50 years, and use of antibiotics within the past 3 months. Phylogenetic relationships between nine of the positive samples from the homeless population were analyzed, showing eight of the nine samples had a high degree of relatedness between the spaA genes of the MRSA strains. This indicates that the same MRSA strain might be transmitted from person-to-person among homeless population. These findings increase our understanding of key differences in MRSA characteristics within homeless populations, as well as risks for MRSA associated with being homeless, such as age and gender, which may then be a useful tool in guiding more effective prevention, treatment, and health care for homeless individuals.

Distribution of Adhesion and Toxin Genes in Staphylococcus aureus Strains Recovered From Hospitalized Patients Admitted to the ICU

Background: Methicillin-resistant Staphylococcus aureus (MRSA) strains are a common cause of emerging nosocomial infections and are a major public health concern. Objectives: The aim of the present study was to determine the prevalence of MRSA, its antibiotic resistance pattern, and the virulence gene profiles in hospitalized patients admitted to ICUs. Methods: During a 6-month period, a total of 70 S. aureus isolates were collected from 249 patients admitted to the ICU in five hospitals. In vitro antibiotic susceptibility testing of the S. aureus isolates was carried out using the Kirby-Bauer disk diffusion method with 16 antibiotic disks. Molecular detection of toxin and adhesion genes was carried out using PCR. Results: All the 70 S. aureus isolates were confirmed to be MRSA strains. The largest number of S. aureus isolates was found in the blood (42.9%) and wound (21.4%) samples. The MDR pattern was detected in 71.4% of the isolates, which were obtained from wound and blood samples. Simultaneous resistance to seven, six, five, four and three drugs was common in 35 (50%), 7 (10%), 8 (11.4%), 11 (15.7%), 2 (2.9%) and 5 (7.1%) isolates, respectively. The frequency of the spa, fnbB, fnbA, clfB, clfA, can, bbp, ebp, etb, eta, pvl, and tst genes was 100%, 75.7%, 74.3%, 78.6%, 71.4%24.3%, 0%, 58.6%, 2.9%, 7.1%, 21.4%, and 51.4%, respectively. In addition, among all the examined genes, the clfB (78.6%) and etb (2.9%) genes had the highest and lowest prevalence respectively. Conclusions: In the present study, we found a high prevalence of MRSA at the hospitals studied. The findings emphasized the increased prevalence of MRSA isolates containing different toxin and adhesion genes, probably accompanied by antimicrobial resistance. Infection with such isolates worsens the clinical outcomes as well as the morbidity and mortality rates in hospitalized patients in ICUs.

Effects of inappropriate empirical antibiotic therapy on mortality in patients with healthcare-associated methicillin-resistant Staphylococcus aureus bacteremia: a propensity-matched analysis.

BackgroundThe purported value of empirical therapy to cover methicillin-resistant Staphylococcus aureus (MRSA) has been debated for decades. The purpose of this study was to evaluate the effects of inappropriate empirical antibiotic therapy on clinical outcomes in patients with healthcare-associated MRSA bacteremia (HA-MRSAB).MethodsA prospective, multicenter, observational study was conducted in 15 teaching hospitals in the Republic of Korea from February 2010 to July 2011. The study subjects included adult patients with HA-MRSAB. Covariate adjustment using the propensity score was performed to control for bias in treatment assignment. The predictors of in-hospital mortality were determined by multivariate logistic regression analyses.ResultsIn total, 345 patients with HA-MRSAB were analyzed. The overall in-hospital mortality rate was 33.0 %. Appropriate empirical antibiotic therapy was given to 154 (44.6 %) patients. The vancomycin minimum inhibitory concentrations of the MRSA isolates ranged from 0.5 to 2 mg/L by E-test. There was no significant difference in mortality between propensity-matched patient pairs receiving inappropriate or appropriate empirical antibiotics (odds ratio [OR] = 1.20; 95 % confidence interval [CI] = 0.71–2.03). Among patients with severe sepsis or septic shock, there was no significant difference in mortality between the treatment groups. In multivariate analyses, severe sepsis or septic shock (OR = 5.45; 95 % CI = 2.14–13.87), Charlson’s comorbidity index (per 1-point increment; OR = 1.52; 95 % CI = 1.27–1.83), and prior receipt of glycopeptides (OR = 3.24; 95 % CI = 1.08–9.67) were independent risk factors for mortality.ConclusionInappropriate empirical antibiotic therapy was not associated with clinical outcome in patients with HA-MRSAB. Prudent use of empirical glycopeptide therapy should be justified even in hospitals with high MRSA prevalence.

Risk factors for methicillin-resistant Staphylococcus aureus carriage among residents in 7 nursing homes in Shanghai, China

Nursing home residents are a population at risk for methicillin-resistant Staphylococcus aureus (MRSA) carriage, but few data about MRSA in this setting in Shanghai are available. The aim of this study is to determine the prevalence and risk factors for MRSA carriage in nursing home residents in Shanghai, China. Four hundred forty-three residents from 7 nursing homes in Shanghai, China, participated in this study; nasal and axillary swabs were obtained from these residents. Laboratory identification for S aureus and antimicrobial susceptibility testing were performed when isolated. Data, including individual resident characteristics and nursing home characteristics, were collected and analyzed. Of the 443 participating residents, 99 (22.3%) and 45 (10.2%) residents were colonized by S aureus and MRSA, respectively. Previous hospitalization (odds ratio [OR], 2.564; 95% confidence interval [CI], 1.214-5.415; P = .014), presence of an invasive device (OR, 3.455; 95% CI, 1.678-7.113; P = .001), chloramphenicol therapy (OR, 7.672; 95% CI, 1.807-32.580; P = .006), and macrolides therapy (OR, 2.796; 95% CI, 1.056-7.403; P = .038) were independent risk factors for MRSA colonization. Low expenditure per month and less good sanitary condition also increased the risk for MRSA colonization. Our study suggests that nursing homes are significant reservoirs for MRSA. Implementation of infection control strategies must be given high priority in nursing homes to fight the high prevalence of MRSA, and increased convenience and feasibility should also be realized with these control strategies for MRSA colonization.

Prevalence of methicillin-resistant Staphylococcus aureus in Canadian commercial pork processing plants.

This study investigated the prevalence of Methicillin-resistant Staphylococcus aureus (MRSA), their spa-types, and antimicrobial resistance profiles at various steps during commercial pork production from three plants designated as A, B and C. Over a period of 1year 2640 samples from three commercial pork plants were obtained on a rotating basis. Sample sources were: nasal swabs after bleeding (NSAB), nasal swab after scalding (NSASs, plant C) or skinning (NSASk, plants A, B), carcass swabs after pasteurization (CSAP, plant C) or washing (CSAW, plants A, B) and retail pork (RP). Overall MRSA prevalence at each sampling point in the pork plants after adjusting for clustering was: 61·93, 28·38 7·58 and 1·21% for NSAB, NSASc/Sk, CSAP/CSAW and RP respectively. The majority of MRSA isolates from the three pork plants belonged to livestock-associated MRSA spa-types t034 and t011 (3·8%; ST398). The mainly human spa-type t002 (15%) was also recovered. All MRSA isolates were resistant to β-lactam and tetracycline antibiotics. Overall resistance to tigecycline was found in about 10% of MRSA isolates while <3% isolates were resistant to daptomycin, gentamicin, quinupristin/dalfopristin and trimethoprim/sulfamethoxazole. A higher prevalence of MRSA in the nasal cavity of incoming pigs was observed at all three plants, but a notable reduction in MRSA along the pork processing steps occurred. The highest prevalence of MRSA was found in the nasal cavity of incoming pigs in three commercial pig slaughter and pork processing plants. A reduction in MRSA prevalence occurred along the processing chain, and pork products from these plants showed significantly lower MRSA than the initial steps of slaughter and processing, suggesting a reduction in MRSA during the slaughter process with minimal cross-contamination.

Prevalence and Molecular Characteristics of Methicillin-resistantStaphylococcus aureusIsolates in a Neonatal Intensive Care Unit

The molecular characteristics of methicillin-resistant Staphylococcus aureus (MRSA) isolated from neonates in a neonatal intensive care unit (NICU) were investigated by multilocus sequence typing (MLST), staphylocoagulase (SC) genotyping, staphylococcal cassette chromosome mec (SCCmec) typing, accessory gene regulator (agr) typing, and the presence of Panton-Valentine leukocidin (PVL). Among the 44 S. aureus isolates from nares in neonates between March and June 2014 at hospital in Busan, 27 (61.4%) were MRSA and 17 (38.6%) were methicillin-susceptible S. aureus (MSSA). The most prevalent clone in MRSA isolates was ST72-SC type Vb-SCCmec IV-agr I (n=26) and the remaining one was ST89-SC type I-SCCmec II-agr II. In MSSA isolates, the prevalent clone was ST121-SC type Va-agr IV (n=13), followed by ST72-SC type Vb-agr I (n=2), ST8-SC type III-agr I (n=1) and ST15-SC type X-agr II (n=1). All isolates did not possess the PVL. The data showed that the neonates in NICU carried high prevalence of ST72 MRSA and remarkably different clones with SC diversity between MRSA and MSSA isolates.

Clinical characteristics and epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in children with cystic fibrosis from a center with a high MRSA prevalence

We describe the clinical characteristics and epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) in children with cystic fibrosis (CF) from the U.S. CF center with the highest MRSA prevalence. Medical records of children with CF were retrospectively reviewed from 1997-2009. MRSA clinical isolates from 2007-2009 were analyzed by polymerase chain reaction and pulsed field gel electrophoresis. The prevalence of MRSA was 1% in 1997 and 49% in 2009. Fifty-five children (26%) had persistent MRSA infection. Sixty-eight percent of MRSA isolates were hospital-associated (HA) MRSA, of which 52% were pulsed-field type USA 100. Ninety-three percent of HA MRSA isolates were clindamycin resistant. Twelve children acquired MRSA before 1 year of age, 83% of whom were hospitalized prior to acquisition of MRSA. Ten of 11 sibling pairs carried indistinguishable MRSA strains. Children with persistent MRSA were hospitalized more often (P = .01), required inhaled medications more frequently (P = .01), and had higher rates of Pseudomonas aeruginosa coinfection (P < .001). MRSA prevalence in children with CF is increasing, and most children are infected with HA MRSA. Exposure to health care facilities and gastrointestinal surgeries may facilitate early acquisition of MRSA. Siblings carry indistinguishable MRSA strains, indicating household transmission of MRSA. Children with persistent MRSA had worse pulmonary morbidity. Coinfection with MRSA and P aeruginosa is likely associated with further increased pulmonary morbidity.

Impact of different diagnostic technologies for MRSA admission screening in hospitals - a decision tree analysis.

BackgroundHospital infections with multiresistant bacteria, e.g., Methicillin-resistant Staphylococcus aureus (MRSA), cause heavy financial burden worldwide. Rapid and precise identification of MRSA carriage in combination with targeted hygienic management are proven to be effective but incur relevant extra costs. Therefore, health care providers have to decide which MRSA screening strategy and which diagnostic technology should be applied according to economic criteria.AimThe aim of this study was to determine which MRSA admission screening and infection control management strategy causes the lowest expected cost for a hospital. Focus was set on the Point-of-Care Testing (PoC).MethodsA decision tree analytic cost model was developed, primarily based on data from peer-reviewed literature. In addition, univariate sensitivity analyses of the different input parameters were conducted to study the robustness of the results.FindingsIn the basic analysis, risk-based PoC screening showed the highest mean cost savings with 14.98 € per admission in comparison to no screening. Rapid universal screening methods became favorable at high MRSA prevalence, while in situations with low MRSA transmission rates omission of screening may be favorable.ConclusionEarly detection of MRSA by rapid PoC or PCR technologies and consistent implementation of appropriate hygienic measures lead to high economic efficiency of MRSA management. Whether general or targeted screening is more efficient depends mainly on epidemiological and infrastructural parameters.

Methicillin-resistant Staphylococcus aureus in Ohio EMS Providers: A Statewide Cross-sectional Study

ABSTRACTThe objective was to determine the nasal carriage prevalence of methicillin-resistant Staphylococcus aureus (MRSA) among emergency medical service (EMS) personnel and the associated risk factors. A cross-sectional study was conducted among Ohio EMS personnel randomly sampled from 84 urban and rural agencies. Surveys assessing demographics, occupational history, health, cohabitation status, and hygiene practice were collected with nasal swabs from those who enrolled. Survey weight adjusted analysis was performed (1) to estimate MRSA nasal carriage prevalence of Ohio EMS providers, and (2) to identify variables associated with MRSA. MRSA was detected in 4.6% (13/280) EMS personnel sampled. After employing a survey-weighted analysis the following risk factors associated with MRSA carriage were identified: those who did not practice frequent hand hygiene after glove use (OR, 10.51; 95% CI, 2.54–43.45; P = 0.0012), living with someone with a recent staphylococcal infection (OR, 9.02; 95% CI, 1.03–78.98; P = 0.0470), and individuals with low frequency of hand washing (< 8 times per shift) (OR, 4.20; 95% CI 1.02–17.27; P = 0.0468). An additional risk factor identified through the logistic regression analysis on the study population was EMS workers with an open wound or skin infection (OR, 6.75; 95% CI, 1.25–36.36; P = 0.0262). However, this was not significant in the survey-weighted analysis. The high prevalence of MRSA in Ohio EMS personnel is both an occupational hazard and patient safety concern. Implementing methods to reinforce CDC guidelines for proper hygiene could decrease MRSA found in the EMS setting. Previous literature suggests that a reduction in MRSA colonization can lead to decreases in transmission and improved health for both patients and personnel.

Review of a two-year methicillin-resistant Staphylococcus aureus screening program and cost-effectiveness analysis in Singapore.

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) poses an increasingly large disease and economic burden worldwide. The effectiveness of screening programs in the tropics is poorly understood. The aims of this study are: (i) to analyze the factors affecting MRSA colonization at admission and acquisition during hospitalization and (ii) to evaluate the cost-effectiveness of a screening program which aims to control MRSA incidence during hospitalization.MethodsWe conducted a retrospective case–control study of patients admitted to the Communicable Disease Centre (CDC) in Singapore between Jan 2009 and Dec 2010 when there was an ongoing selective screening and isolation program. Risk factors contributing to MRSA colonization on admission and acquisition during hospital stay were evaluated using a logistic regression model. In addition, a cost-effectiveness analysis was conducted to determine the cost per disability-adjusted life year (DALY) averted due to implementing the screening and isolation program.ResultsThe average prevalence rate of screened patients at admission and the average acquisition rate at discharge during the study period were 12.1 and 4.8 % respectively. Logistic regression models showed that older age (adjusted odds ratio (OR) 1.03, 95 % CI 1.02–1.04, p < 0.001) and dermatological conditions (adjusted OR 1.49, 95 % CI 1.11–1.20, p = 0.008) were independently associated with an increased risk of MRSA colonization at admission. Age (adjusted OR 1.02, 95 % CI 1.01–1.03, p = 0.002) and length of stay in hospital (adjusted OR 1.04, 95 % CI 1.03–1.06, p < 0.001) were independent factors associated with MRSA acquisition during hospitalization. The screening and isolation program reduced the acquisition rate by 1.6 % and was found to be cost saving. For the whole study period, the program cost US$129,916, while it offset hospitalization costs of US$103,869 and loss of productivity costs of US$50,453 with −400 $/DALY averted.DiscussionThis study is the first to our knowledge that evaluates the cost-effectiveness of screeningand isolation of MRSA patients in a tropical country. Another unique feature of the analysis is the evaluationof acquisition rates among specific types of patients (dermatological, HIV and infectious disease patients)and the comparison of the cost-effectiveness of screening and isolation between them.ConclusionsOverall our results indicate high MRSA prevalence that can be cost effectively reduced by selective screening and isolation programs in Singapore.

Molecular and phenotypic characteristics of methicillin-resistant Staphylococcus aureus isolated from hospitalized patients.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of infections acquired in both community and hospital settings. In this study, MRSA isolated from different sources of hospitalized patients was characterized by molecular and phenotypic methods. A total of 123 S. aureus isolates were characterized according to their genetic relatedness by repetitive element sequence based-PCR (REP-PCR), in vitro antimicrobial susceptibility profile, SCCmec typing and presence of seven virulence factor-encoding genes. REP-PCR fingerprinting showed low relatedness between the isolates, and the predominance of one specific lineage or clonal group was not observed. All isolates were susceptible to teicoplanin and linezolide. All isolates were resistant to cefoxitin and penicillin, and the majority were also resistant to one or more other antimicrobials. Fifty isolates (41.7%) were intermediately resistant to vancomycin. Most isolates harbored SCCmec type II (53.7%), followed by type I (22.8%), type IV (8.1%) and type III (1.6%). All isolates harbored at least two virulence factor-encoding genes, and the prevalence was as follows: coa, 100%; icaA, 100%; hla, 13.0%; hlb, 91.1%, hld, 91.1%; lukS-PV and lukF-PV, 2.4%; and tst, 34.1%. A positive association with the presence of hla and SCCmec type II, and tst and SCCmec type I was observed. This study showed the high virulence potential of multidrug-resistant MRSA circulating in a teaching hospital. A high prevalence of MRSA showing intermediate vancomycin resistance was also observed, indicating the urgent need to improve strategies for controlling the use of antimicrobials for appropriate management of S. aureus infections.

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.

Predicting MSSA in Acute Hematogenous Osteomyelitis in a Setting With MRSA Prevalence.

Increased severity of illness in patient with acute hematogenous osteomyelitis (AHO) with methicillin-resistant Staphylococcus aureus (MRSA) necessitates prompt intervention, but overtreatment of methicillin-sensitive S. aureus (MSSA) may contribute to antibiotic resistance. Therefore, predicting methicillin sensitivity in suspected AHO is desirable. A previously published prediction algorithm has not performed well in settings with high prevalence of MRSA. We sought to develop a predictive equation using presenting factors to predict MRSA in our patient population with a predominance of MRSA. A retrospective chart review was performed. Consecutive cases of AHO with positive blood or bone cultures were identified at a single children's hospital. Presenting features were recorded including duration of symptoms, weight-bearing, prior antibiotic use, vital signs, complete blood count, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Univariate comparison was made between the groups with MRSA and MSSA. Continuous variables were compared with t tests and discrete variables were compared using the Fischer exact test. Logistic regression was performed using a forward stepwise regression to develop a model to predict MRSA. A total of 68 patients formed the study group, and 60% had MRSA (41 MRSA, 27 MSSA). Temperature, respiratory rate, heart rate, white blood cell count, absolute neutrophil count (ANC), ESR), and CRP were significantly higher in MRSA cases, whereas platelets were lower. Logistic regression resulted in a model utilizing temperature, ANC, and CRP. This model correctly predicted 87% of cases (92% of MRSA and 79% of MSSA) with an area under the curve of 0.919±0.035 with a 95% confidence interval of 0.851, 0.987. A logistic regression model incorporating temperature, ANC, and CRP correctly predicts methicillin resistance of S. aureus in 87% of cases. The model differs from one developed at an institution with a low rate of MRSA. Prediction of MRSA could help direct antibiotic management, whereas prediction of MSSA could help prevent overuse of antibiotics directed against MRSA. Diagnostic study level IV.

Epidemiology of Staphylococcus aureus in Bangalore, India: emergence of the ST217 clone and high rate of resistance to erythromycin and ciprofloxacin in the community.

This study aimed to determine the antibiotic susceptibility pattern of Staphylococcus aureus (SA) and the circulating clones in Bangalore, India. Susceptibility testing was performed for all cases of SA infections in a tertiary-care hospital. Panton-Valentine leucocidin (PVL) encoding genes were detected, and sequence type and spa type were determined. Out of the 92 collected strains, 52.2% were methicillin-resistant SA (MRSA), isolated from community-acquired (CA) infections in 60.4% and hospital-acquired (HA) infections in 39.6%. S. aureus isolates were also highly resistant to erythromycin (54.3%) and ciprofloxacin (70.6%) in methicillin-susceptible SA (MSSA) and MRSA, as well as in CA and HA infections. MRSA were found to be significantly more resistant to gentamicin (p <0.001), cotrimoxazole (p <0.001) and ciprofloxacin (p 0.001) than MSSA, but no significant difference was observed between CA- and HA-SA. ST217 appeared as a new emerging and prevalent clone, but ST772 remained the predominant clone, all being PVL-positive isolates. Our study points out the high prevalence of MRSA, even in the community, and the worrying increase of resistance to ciprofloxacin and erythromycin among CA-MSSA. Emergence of clone ST217 is reported for the first time in India.

The Role of Methicillin-Resistant Staphylococcus aureus in Clinical infections in Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, South Western Nigeria

This study determined the prevalence of Methicillin-resistant Staphylococcus aureus (MRSA) from 246 clinical samples collected at a tertiary care hospital, its antimicrobial susceptibility, spectrum of infections and the associated risk factors. Standard procedures were used for isolation, screening, and susceptibility testing. The result showed that 41 (40.2%) out of 102 S. aureus isolated were methicillin-resistant while 61 (59.8%) were methicillin-sensitive. The prevalence rate of MRSA for male and female group was 37.3% and 43.1% respectively. Thirty (73.2%) methicillin-resistant S. aureus isolates were obtained from inpatients while 11 (26.8%) were from outpatients. MRSA were significantly isolated from the Orthopaedic ward (OR=3.36; P=0.031) and the antenatal ward (OR=8.33; P=0.037). High resistance rates were exhibited by MRSA isolates to cefotaxime (102, 79.4%) and clindamycin (102, 49%) but had low resistance rates to gentamicin (102, 27.5%) and chloramphenicol (n=102, 28.4%). MRSA were more significantly resistant to gentamicin (χ 2 =12.284; p=0.0001), clindamycin (χ 2 =20.234; p=0.0001) and cefotaxime (χ 2 =13.812; p=0.0002) than MSSA. Thirtytwo (78%) out of 41 MRSA isolated were multidrug resistant. All isolates (MRSA and MSSA) were susceptible to vancomycin with MIC values ranging from 2.1 to 0.12 µg/ml. This study showed a high prevalence of MRSA in clinical infections that were resistant to treatment options in OAUTHC, Ile-Ife. Being in the antenatal and orthopaedic wards is a predictor of MRSA infections in the hospital. In spite of reports that vancomycin resistant Staphylococcus aureus is increasing, it is yet to be a problem in the hospital and vancomycin remains a drug of choice for the treatment of MRSA and multidrug resistant Staphylococcus aureus infections.

Occupational determinants of methicillin-resistant Staphylococcus aureus colonization among healthcare workers: a longitudinal study in a rehabilitation center.

BACKGROUND Staphylococcus aureus carriage among healthcare workers (HCWs) is a concern in hospital settings, where it may provide a reservoir for later infections in both patients and staff. Earlier studies have shown that the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) carriage in HCWs is highly variable, depending notably on location, hospital department type, MRSA prevalence among patients, and type of contacts with patients. However, MRSA incidence in HCWs and its occupational determinants have seldom been studied. METHODS A prospective, observational cohort study was conducted between May and October 2009 in a French rehabilitation center hospital. HCWs and patients were screened weekly for S. aureus nasal carriage. Methicillin-susceptible S. aureus and MRSA prevalence and incidence were estimated and factors associated with MRSA acquisition were identified using generalized estimating equation regression methods. RESULTS Among 343 HCWs included in the analysis, the average prevalence was 27% (95% CI, 24%-29%) for methicillin-susceptible S. aureus and 10% (8%-11%) for MRSA. We observed 129 MRSA colonization events. According to the multivariable analysis, high MRSA prevalence level among patients and HCW occupation were significantly associated with MRSA acquisition in HCWs, with assistant nurses being more at risk than nurses (odds ratio, 2.2; 95% CI, 1.4-3.6). CONCLUSIONS Our findings may help further our understanding of the transmission dynamics of MRSA carriage acquisition in HCWs, suggesting that it is notably driven by carriage among patients and by the type of contact with patients.