Prevalence Of MRSA Research Articles

Antimicrobial Susceptibility Pattern of <i>Staphylococcus aureus</i> with Emphasize on Methicilin Resistance with Patients Postoperative and Wound Infections at Yekatit 12 Hospital Medical College in Ethiopia

Background: <i>Staphylococcus aureus</i> particularly methicilin resistant <i>S. aureus</i> strains are one of the major causes of community and hospital acquired bacterial infections, often causing postoperative and burn wound infections. In-vitro determination of drug resistance patterns of <i>S. aureus</i> is critical for the selection of effective drugs for the treatment of staphylococci infections. Objective: The aim of this study was to determine methicillin and antimicrobial susceptibility pattern of <i>S. aureus</i> from postoperative and burn wound patients in Ethiopia. Materials and Methods: A cross sectional study was conducted among 378 patients at Yekatit 12 Hospital Medical College from September 2013 to August 2014 in Ethiopia. Swabs from postoperative and burn wound were collected. Swabs were cultured on blood agar and mannitol salt agar and incubated at 35-37°C aerobically for 18-24 hours. Cultures with typical characteristics were identified to <i>S. aureus</i> by DNAse agar test. <i>S. aureus</i> were then screened for MRSA using 30g cefoxitin disc. The drug susceptibility patterns of <i>S. aureus</i> to eleven drugs were determined by disc diffusion procedure and agar dilution for vancomycin. All <i>S. aureus</i> isolates examined for beta-lactamase production by employing nitrocefin. Data were analyzed using SPSS version 20 software and logistic regressions were applied to assess any association between dependent and independent variables. P values < 0.05 were taken as statistically significant. Results: Of the 378 swabs analyzed, <i>S. aureus</i> was recovered from 179 (47.4%). The prevalence of <i>S. aurues</i> was higher in females than males 95(53%) versus 84(47%). Out of 179 <i>S. aureus</i> isolates, 67(37.43%) were found out to be MRSA and the remaining 112(62.57%) were MSSA. <i>S. aureus</i> isolates were more resistant to penicillin 172(96.1%) and least resistant for vancomycin 10(5.6%) and cephalothin 9(5.0%). MRSA isolates were 67(100%) resistant for penicillin, 63(94.0%) for erythromycin, 62(92.5%) for trimethoprim-sulfamethoxazole and least resistant for cephalothin 9(13.4%) and vancomycin 10(15.0%). Among 179 <i>S. aureus</i> isolates, 145(81.0%) were beta-lactamase producers. Furthermore, of 67 MRSA isolates, 61(91.0%) and out of 112 MSSA strains 99(88.4%) were beta-lactamase producers. Conclusion: In this study <i>S. aureus</i> isolates exhibited very high degree of resistance to different antibiotics. The prevalence of MRSA was high and this should necessitate caution in prescription of antibiotics without proper indication. The isolates were also multidrug resistant to several combinations of the tested antibiotics. The emergence of vancomycin resistant <i>S. aureus</i> highlights the value of prudent prescribing of antibiotics and avoiding their irrational use.

Cross sectional analysis of aerobic bacteria and their antibiotic susceptibility pattern among orthopedic wound infections at a tertiary care hospital in Karnataka

Background: Orthopedic wound infections are one of the important causes of morbidity and are difficult to treat. With the development of antimicrobial resistance, the situation has further worsened and it has become difficult to manage them by conservative means leading to further deterioration in health and wellbeing of the patients. To avoid such complications, orthopedic wound infections need to be managed at the earliest by microbial isolation and appropriate antibiotic administration. Objectives: 1. To study the profile of aerobic bacteria affecting the orthopedic wounds. 2. To study the pattern of their antibiotic susceptibility. Methods: A Cross sectional study was conducted using secondary data of orthopedic wound infection cases maintained in the microbiology laboratory registers for a period of 1 year from September 2014 to August 2015. The bacteriological agents were isolated, identified and their antibiotic susceptibility patterns were determined using standard protocols. Analysis was done using MS Excel 2010. Results and interpretation: Our study yielded 249 (56.08%) positive culture cases. Prevalence of Gram positive bacteria was more than Gram negative bacteria. Staphylococcus aureus was the predominant causative agent followed by Pseudomonas aeruginosa. The prevalence of MRSA was 25%. All the Gram positive cocci isolates were sensitive to linezolid and vancomycin. Members of Enterobacteriaceae family showed high sensitivity to Meropenem followed by amikacin. Polymyxin B and piperacillin-tazobactam were the most effective antibiotics among non-fermenters. All the Gram negative bacteria were resistant to penicillin and cephalosporins. Conclusion: Microbial analysis of samples and their antibiogram is recommended for proper management of Orthopaedic wounds. Key words: Antibiogram, Bacterial isolates, Orthopaedic wound infections

Assessing the Prevalence of Staphylococcus Aureus, Particularly MRSA, from Anterior Nares of Medical Students

Introduction: Staphylococcus aureus is a frequent cause of infections in both the community and hospital. Methicillin-resistant Staphylococcus aureus continues to be an important nosocomial pathogen and infections are often difficult to manage due to its resistance to multiple antibiotics. Aims and objectives: Aim of the study is to determine the nasal carriage rate of S. aureus and also to detect the antimicrobial susceptibility patterns of the isolates, which include methicillin resistance among medical students. Inclusion criteria: Medical students who have just passed 1st yr and started attending clinical postings. Exclusion criteria: History of antibiotic usage, students using nasal drops for any treatment, recent hospitalisation. Materials and methods: Nasal swabs were collected, and isolation of Staphylococcus aureus was and they were identified using conventional culture methods. Routine antibiotic susceptibility test was performed by modified Kirby-Bauer disc diffusion method by using 0.5 Mc Farland standards. Methicillin resistance is be detected by using cefoxitin disc as per CLSI guidelines. Results: Of 91 samples the nasal carriage of S.aureus is seen in 18 students (19.7%), among them MRSA is identified in 3 students (11.1%). Overall prevalence of MRSA is 3 out of 91(2.1%). Keywords: Antibiotic susceptibility testing, CLSI guide lines, Kirby-Bauer disc diffusion method, MRSA, Nasal carriage

Prevalence and Genetic Diversity of Livestock-Associated Methicillin-Resistant Staphylococcus aureus on Belgian Pork

Since the first description of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA), a high prevalence was observed in pigs. At present, questions remain about the transmission of LA-MRSA to the general human population through pork. The objectives of the present study were to determine the prevalence of LA-MRSA in Belgian pork and to determine the role of the pork production chain and butcheries in transmission of LA-MRSA to the human population. Pig meat samples (chops, bacon, minced pork, ribs, forelimbs, and ears; n = 137) originating from four butcheries (A through D) were spread plated on ChromID MRSA plates both before and after overnight enrichment culture. Suspect colonies were confirmed using a MRSA-specific triplex PCR assay and a CC398-specific PCR assay. The isolates (n = 147) were further characterized by SCCmec typing, multiple-locus variable number tandem repeat analysis, and antimicrobial susceptibility testing, a selection of isolates were subjected to pulsed-field gel electrophoresis and spa typing. Direct plating revealed a MRSA prevalence of 8%. After enrichment, MRSA was isolated from 98 (72%) of 137 samples of which the majority were from rib, ear, and forelimb. The majority (97%) of obtained isolates belonged to CC398, the main LA-MRSA type. A high level of genetic diversity was noted among the isolates from one butchery. Thirty antimicrobial susceptibility profiles were found; 13 and 9% of the isolates had Cip-Tet-Tri and Gen-Kan-Tet-Tob-Tri profiles, respectively. These results indicate the importance of enrichment for MRSA detection of pork. The observed genetic diversity of the isolates indicated that the pork production chain can be considered a source of multiple MRSA types that could be transmitted to the human population through cross-contaminated meat.

Transmission of MRSA between humans and animals on duck and turkey farms.

The objectives of this study were to estimate the prevalence of MRSA on duck and turkey farms, identify risk factors for human carriage and study transmission between animals and humans. On 10 duck and 10 turkey farms, samples were taken from animals, poultry houses, home residences and humans and cultured using pre-enrichment and selective enrichment. MRSA isolates were typed by spa typing and multiple-locus variable number tandem repeat analysis (MLVA) typing. A subset of isolates from animals and humans was investigated using whole-genome mapping. MRSA was found on one duck farm and three turkey farms. On duck farms, all humans were MRSA negative. On turkey farms, 5 of 11 farmers, 2 of 32 family members and 15 of 49 samples from the home residences were MRSA positive. Individuals with daily contact with turkeys were significantly more often MRSA positive than individuals without daily contact. All MRSA isolates belonged to livestock-associated MLVA complex 398, belonged to spa type t011, were negative for Panton-Valentine leucocidin, were mecC negative and were mecA positive. Whole-genome mapping proved a valuable tool to study the transmission of livestock-associated MRSA and showed that on two turkey farms the isolates from the animals and humans were indistinguishable or closely related, indicating transmission. MRSA carriage in individuals in daily contact with turkeys was significantly higher than that in individuals only living on the farms or than in the general Dutch population. Therefore, persons with a high degree of contact with turkeys have an increased risk of MRSA carriage, and we propose that they should be screened prior to hospitalization in order to decrease the risk of nosocomial transmission.

Antimicrobial resistance and population structure of Staphylococcus aureus recovered from pigs farms

Staphylococcus aureus is a burden in human and veterinary medicine. During the last decade, an increasing number of studies reported the presence of livestock-associated methicillin-resistant S. aureus (LA-MRSA) clonal complex (CC) 398 in pigs. During 2013, a survey was performed in pig farms (n=328) randomly selected over Belgium, to monitor the current epidemiological situation of LA-MRSA among asymptomatic pigs and compare with former data to determine possible evolutions. Per farm, nose swabs were taken from 20 animals and pooled. MRSA was detected in 215 farms. Most isolates belonged to CC398 (n=211), and the remaining were ST9/t337 (n=1), ST80/t044 (n=2) and ST239/t4150 (n=1). A large diversity (n=19) of spa-types was found in the CC398 isolates. More than 90% of the isolates were non-wild type (NWT) to tetracycline and trimethoprim. NWT isolates were also found for ciprofloxacin (61.1%), clindamycin (64.4%), erythromycin (57.8%), kanamycin (43.1%) and gentamicin (45.5%). Microarray analysis showed that most CC398 isolates carried genes encoding resistance to tetracycline [tet(M)], macrolide–lincosamide–streptogramin group [erm(B), erm(C), lnu(A), vga(A)], aminoglycosides (aacA-aphD,aa dD, aphA3, sat) and/or phenicols (fexA). One CC398 isolate carried the multi-resistance gene cfr. The non-CC398 isolates carried virulence genes, as the egc-like cluster. The ST80 strain carried the Panton–Valentine leukocidin gene and corresponded to the community-acquired (CA-)MRSA ST80-IV European clone. The MRSA prevalence among pigs in Belgium remains similar to previous studies but a larger diversity in spa-types has been detected in this study. The recovery of CA-MRSA from livestock indicates that one should remain vigilant to the evolution of LA-MRSA in pigs.

Effects of Reducing Antimicrobial Use and Applying a Cleaning and Disinfection Program in Veal Calf Farming: Experiences from an Intervention Study to Control Livestock-Associated MRSA.

With the ultimate aim of containing the emergence of resistant bacteria, a Dutch policy was set in place in 2010 promoting a reduction of antimicrobial use (AMU) in food-producing animals. In this context, a study evaluated strategies to curb livestock-associated methicillin resistant Staphylococcus aureus (LA-MRSA). Fifty-one veal calf farms were assigned to one of 3 study arms: RAB farms reducing antimicrobials by protocol; RAB-CD farms reducing antimicrobials by protocol and applying a cleaning and disinfection program; and Control farms without interventions. MRSA carriage was tested in week 0 and week 12 of 2 consecutive production cycles in farmers, family members and veal calves. Interventions were validated and a cyclic rise in MRSA-prevalence in animals was shown with a more moderate increase in RAB farms. Prevalence in humans declined parallel over time in the study arms but RAB farms were at the lowest MRSA levels from the beginning of the study. In RAB-CD farms, human and animal prevalence did not differ from Control farms and MRSA air loads were significantly higher than in the other study arms. Mimicking the national trend, an overall AMU decrease (daily dosages per animal per cycle (DDDA/C)) was observed over 4 pre-study and the 2 study cycles; this trend did not have a significant effect on a set of evaluated farm technical parameters. AMU was positively associated with MRSA across study arms (ORs per 10 DDDA/C increase = 1.26 for both humans (p = 0.07) and animals (p = 0.12 in first cycle)). These results suggest that AMU reduction might be a good strategy for curbing MRSA in veal calf farming, however the specific cleaning and disinfecting program in RAB-CD farms was not effective. The drop in MRSA prevalence in people during the study could be attributed to the observed long-term AMU decreasing trend.

Hospital outpatient clinics as a potential hazard for healthcare associated infections.

Healthcare acquired infections are no longer confined to the hospital environment. Recently, many reported outbreaks have been linked to outpatient settings and attributed to non-adherence to recommended infection-prevention procedures. This study was divided into two parts: The first is a descriptive cross-sectional part, to assess the healthcare personnel's knowledge and compliance with Standard Precautions (SP). The second is an intervention part to assess the role of health education on reducing the level of environmental and reusable medical equipment bacterial contamination. Assessment of the doctors' and nurses' knowledge and compliance with SP was performed using a self-administered questionnaire. Assessment of environmental cleaning (EC) and reusable medical equipment disinfection has been performed using aseptic swabbing method. The extent of any growth was recorded according to the suggested standards: (A) Presence of indicator organisms, with the proposed standard being <1cfu/cm(2). These include Staphylococcus aureus (including methicillin-resistant Staphylococcus aureus, MRSA), Enterococci, including vancomycin-resistant Enterococci (VRE) and various multidrug-resistant Gram-negative bacilli. (B) Aerobic colony count, the suggested standard is <5cfu/cm(2). The effect of health education intervention on cleaning and disinfection had been analyzed by comparing the difference in cleaning level before and after interventional education. Good knowledge and compliance scores were found in more than 50% of participants. Primary screening found poor EC and equipment disinfection as 67% and 83.3% of stethoscopes and ultrasound transducers, respectively, were contaminated with indicator organisms. For all indicator organisms, a significant reduction was detected after intervention (p=0.00). Prevalence of MRSA was 38.9% and 16.7%, of the total S. aureus isolates, before and after intervention, respectively. Although 27.8% of the total Enterococcus isolates were VRE before intervention, no VRE isolates were detected after intervention. These differences were significant. Development and monitoring of the implementation of infection prevention policies and training of HCP is recommended.

Prevalence of Enterotoxin Genes and Antibacterial Susceptibility Pattern of Staphylococcus aureus Strains Isolated from Animal Originated Foods in West of Iran.

The aims of our study were to evaluate the prevalence of Staphylococcus aureus (S. aureus) strains in food samples of animal origin, examine their antibacterial susceptibility pattern, and to detect staphylococcal enterotoxin (SEs) genes and the mecA gene in isolated S. aureus strains using the polymerase chain reaction (PCR). . A total of 1050 food samples including 671 raw milk and dairy products and 379 raw meats were collected between September 2013 and June 2014 in Hamadan, Iran. Food samples were analyzed for S. aureus identification. The antibiotic susceptibility pattern of all isolates was determined using the disk agar diffusion method followed by detecting mecA resistance gene using PCR. In addition, harboring of SE genes were determined using a multiplex PCR assay targeting nine genes. . A total of 98 (9.3%) S. aureus strains were isolated from 1050 food samples. Of the 98 isolates examined, the most frequent resistance was observed to erythromycin (30.6%), followed by tetracycline (29.6%), gentamicin (27.6%), clindamycin (26.5%), ciprofloxacin and rifampin (24.5%), trimethoprim-sulfamethoxazole (14.3%), and cefoxitin (5.1%). All cefoxitin resistant isolates were positive for mecA. The prevalence of SEs was 77.6% (n=76). Among the genes that code classic enterotoxins, sea was the most frequent and was carried by 25.5% of isolates, followed by see in 18.4%, sed in 11.2%, sec in 5.1%, and seb in 4.1% of isolates. Among the detected enterotoxins, seg was the predominantly identified enterotoxin gene in isolates with prevalence of 35.7%. The seh gene with prevalence of 1% and sei gene with 3.1% were other detected enterotoxins with low frequencies. . The high prevalence of SE genes detected indicates a potential risk for causing animal-originated food poisoning. The increasing prevalence of community-acquired MRSA and its emerging antibiotic resistance in foods is a serious problem for public health.

Rapid molecular diagnosis using femA mecA real-time PCR for staphylococcal bacteraemia improves early appropriate antibiotic prescribing: a randomised clinical trial

Vancomycin overuse exerts a selective pressure for VRE and VISA and has been associated with poorer outcomes than beta-lactams when treating MSSA. Rapid determination of methicillin susceptibility should be particularly helpful to spare vancomycin in a setting where MRSA prevalence is low.

Analysis of pathogen spectrum and resistance of clinical common organisms causing bloodstream infections, hospital-acquired pneumonia and intra-abdominal infections from thirteen teaching hospitals in 2013

To investigate the spectrum and antimicrobial resistance of major pathogensthat causing nosocomial infections in China, 2013. Nosocomial cases as well as pathogens causing bloodstream infections (BSI), hospital-acquired pneumonia (HAP) and intra-abdominal infections (IAI) from 13 teaching hospital around China were collected. The minimum inhibitory concentrations (MICs) were determined by the agar dilution method. The CLSI M100-S23 criteria were used for interpretation. Of all cases, 1 022 cases were from BSI, 683 from HAP and 674 from IAI.Escherichia coli and Klebsiella pneumoniae were the most prevalent pathogens causing BSI and IAI while Acinetobacter baumanii (34.6%) and Pseudomonas aeruginosa were dominated in HAP. Tigecycline, imipenem and meropenem exhibited high potency against Enterobacteriaceae and the susceptibilities rates were 95.6%, 94.2%and 95.2% respectively. Enterobacteriaceae demonstrated high resistance against cephalosporins (52.3%) and fluoroquinolones (38.9%) but were susceptible to β-lactam+inhibitor. Of all the Enterobacteriaceae, 30.5% were ESBLs positive and 4.3% were carbapenem resistant. Acinetobacter baumanii showed low susceptibilities to the microbial agents except for tigecycline (90.5%) and colistin (100%). The rate of carbapenem resistant Acinetobacter baumanii was 76.6%. Amikacin, ciprofloxacin, cefepime and piperacillin/tazobactam showed high antibacterial activity against Pseudomonas aeruginosa with susceptible rate 88.5%, 77.6%, 72.7% and 64.5% respectively. The resistant rate to imipenem and meropenem were 42.1% and 32.2%. All Staphylococcus aureus (166 strains) were susceptible to tigecycline, linezolid, daptomycin and glycopeptides. MRSA accounted for 46.9% of all the Staphylococcus aureus. The prevalence of MRSA in IAI (55.2%) and HAP (54.4%) were higher that that in BSI (35.0%). No Enterococcus strains were found resistant to tigecycline, linezolid and daptomycin. VRE was found in Enterococcus faecium, accounting for 1.9% of all Enterococcus faecium strains. Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa are the most common pathogens causing nosocomial infections. Nosocomial pathogens showed high susceptibilities against tigecycline. For ESBLs-producing Enterobacteriaceae strains, β-lactam+Inhibitor show high antibacterial activities. Vancomycin, teicoplanin and linezolid exhibit high potency to Staphylococcus aureus and Enterococcus.

Dose-Response Relationship between Antimicrobial Drugs and Livestock-Associated MRSA in Pig Farming1

The farming community can be a vehicle for introduction of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in hospitals. During 2011-2013, an 18-month longitudinal study aimed at reducing the prevalence of LA-MRSA was conducted on 36 pig farms in the Netherlands. Evaluations every 6 months showed a slight decrease in MRSA prevalence in animals and a stable prevalence in farmers and family members. Antimicrobial use, expressed as defined daily dosages per animal per year, decreased 44% during the study period and was associated with declining MRSA prevalence in pigs. MRSA carriage in animals was substantially higher at farms using cephalosporins. Antimicrobial use remained strongly associated with LA-MRSA in humans regardless of the level of animal contact. A risk factor analysis outlined potential future interventions for LA-MRSA control. These results should encourage animal and public health authorities to maintain their efforts in reducing antimicrobial use in livestock and ask for future controlled intervention studies.

Livestock-associated MRSA in household members of pig farmers: transmission and dynamics of carriage, a prospective cohort study.

This prospective cohort study describes carriage of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in household members from 49 farrowing pig farms in the Netherlands (2010–2011). Of 171 household members, 4% were persistent MRSA nasal carriers, and the MRSA prevalence on any given sampling moment was 10% (range 7-11%). Working in the stables (of which 98% was MRSA-positive, prevalence ratio (PR) = 2.11 per 10 hours), working with sows (PR=1.97), and living with an MRSA-positive pig farmer (PR=4.63) were significant determinants for MRSA carriage. Significant protective factors were carriage of methicillin-susceptible Staphylococcus aureus (MSSA) (PR=0.50), and wearing a facemask when working in the stables (37% decreased prevalence). All MRSA strains during the study period were known livestock-associated types. The bacteriophage φ3 was not found in household members. Transmission from pigs and the environment appeared to be important determinants; human-to-human transmission could not sufficiently be differentiated. Wearing a facemask when working in the stables and carriage of MSSA are potential interventional targets.

Long-term persistence of a multi-resistant methicillin-susceptible Staphylococcus aureus (MR-MSSA) clone at a university hospital in southeast Sweden, without further transmission within the region.

The objective of this study was to characterise isolates of methicillin-susceptible Staphylococcus aureus (MSSA) with resistance to clindamycin and/or tobramycin in southeast Sweden, including the previously described ECT-R clone (t002) found in Östergötland County, focusing on clonal relatedness, virulence determinants and existence of staphylococcal cassette chromosome (SCC) mec remnants. MSSA isolates with resistance to clindamycin and/or tobramycin were collected from the three county councils in southeast Sweden and investigated with spa typing, polymerase chain reaction (PCR) targeting the SCCmec right extremity junction (MREJ) and DNA microarray technology. The 98 isolates were divided into 40 spa types, and by microarray clustered in 17 multi-locus sequence typing (MLST) clonal complexes (MLST-CCs). All isolates with combined resistance to clindamycin and tobramycin (n = 12) from Östergötland County and two additional isolates (clindamycin-R) were designated as spa type t002, MREJ type ii and were clustered in CC5, together with a representative isolate of the ECT-R clone, indicating the clone's persistence. These isolates also carried several genes encoding exotoxins, Q9XB68-dcs and qacC. Of the isolates in CC15, 83% (25/30) were tobramycin-resistant and were designated spa type t084. Of these, 68% (17/25) were isolated from new-borns in all three counties. The persistence of the ECT-R clone in Östergötland County, although not found in any other county in the region, carrying certain virulence factors that possibly enhance its survival in the hospital environment, highlights the fact that basic hygiene guidelines must be maintained even when MRSA prevalence is low.

Modified Protocol Decreases Surgical Site Infections after Total Knee Arthroplasty.

We investigate the effectiveness of a comprehensive aseptic protocol in reducing surgical site infection (SSI) after knee arthroplasty in a single medical center with a high prevalence of MRSA. A database of all patients in a single center undergoing primary knee arthroplasty between 2005 and 2011 was reviewed for SSI using Centers for Disease Control criteria and AAOS guidelines. All patients were treated with an aseptic protocol consisting of the following: 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 total knee arthroplasty SSI rate to our institutional historical control (2001-2004) and to contemporary literature. Among 1,224 patients, 70% were ASA class >2 and 64% had a body mass index (BMI) > 30 kg/m(2). We found an overall 0.49% infection rate, significantly lower than that of our institutional historical control (0.49 vs. 2.24%, p < 0.001; odds ratio [OR], 0.21; number needed to treat [NNT], 145) and seven recently published reports (p < 0.001-0.042; OR, 0.07-0.42). Compared with these reports, significantly more of our patients were ASA class > 2, BMI > 30 kg/m(2), immunosuppressed, or had rheumatoid arthritis. Our aseptic protocol decreases SSI in a high-risk population undergoing knee arthroplasty in a medical center and community with a high prevalence of MRSA.

Eradication of respiratory tract MRSA at a large adult cystic fibrosis centre

The prevalence of MRSA in patients with CF is increasing. There is no consensus as to the optimum treatment. An observational cohort study of all patients with MRSA positive sputum, 2007-2012. All eradication attempts with subsequent culture results were reviewed. Single vs dual antibiotic regimens were compared for both new and chronic infections. 37 patients (median FEV1 58.7 (27.6-111.5)% predicted) were identified, of which 67.6% (n = 25) had newly acquired MRSA. Compared with single regimens, a high proportion of dual regimens achieved MRSA eradication (84.6% vs 50%; p = 0.1) for new infections. Rifampicin/Fusidic acid was associated with high success rates (100% vs 60% for other dual regimens (p = 0.13)). Compared with new infections, chronic MRSA was much less likely to be eradicated (18.2%, p = 0.01). Combined antibiotic therapy, particularly Rifampicin/Fusidic acid, is a well-tolerated and effective means of eradicating MRSA in patients with cystic fibrosis.

Methicillin resistant Staphylococcus aureus colonisation: A three year experience with a surveillance program, in a tertiary neurocare centre

BackgroundMethicillin resistant Staphylococcus aureus (MRSA) is an important nosocomial pathogen. A strong correlation between the invasive and the nasal carriage strains in the patients has been well established indicating the need to eliminate the carriage of MRSA to prevent the transmission. The objectives of this study are to assess the prevalence of MRSA colonisation in patients from ICUs and high risk wards for a period of 33 months, (2011–2013) by routine active surveillance culture, and also to evaluate the role of extra-nasal sites in the screening. MethodsThe nasal and extra-nasal specimens were obtained from patients using sterile cotton swab. Staphylococci were identified based on colony morphology on blood agar, Gram's staining and coagulase test. The Staphylococcus aureus (S. aureus) isolates were screened for methicillin resistance by Kirby–Bauer disc diffusion method using oxacillin (1μg) and cefoxitin (30μg) discs and reported according to CLSI guidelines. ResultsOut of the 5372 nasal samples tested, S. aureus was identified in 14.1% patients. The rate of methicillin resistance was 31.7% of the total S. aureus isolates. The overall prevalence of MRSA was 4.5%.Out of 219 extra-nasal samples tested, 4.1% of the patients carried MRSA in sites like axilla and groin without nasal carriage. ConclusionOur results encourage us to continue with the screening program so as to prevent the high risk patients contracting endogenous infections thus controlling the transmission and spread and also the addition of extra-nasal site; either axilla or groin might increase the screening efficiency in non nasal colonisers.

Community acquired MRSA infections—Three recent cases and an overview of CA MRSA infections

Abstract Skin and soft tissue infections caused by Staphylococcus aureus are commonly encountered in pediatric practice. Staph infections acquired in the hospital setting are generally methicillin resistant. However these days, infections which are clearly “community acquired” are increasingly found to be due to methicillin resistant Staphylococcus —so called CA MRSA. Community-associated MRSA (CA-MRSA) refers to a MRSA infection with onset in the community in an individual lacking established MRSA risk factors, such as recent hospitalization, surgery, residence in a long-term care facility, receipt of dialysis, or presence of invasive medical devices. Literature from western countries suggests a significant prevalence of CA MRSA and the same scenario seems to be developing in our country. We had three recent cases of such CA MRSA infections, with no prior contact with hospital, all “community acquired” which was also reflected in their antibiotic sensitivity pattern.

Paediatric bacteraemias in tropical Australia.

Bacteraemias in children are an important cause of morbidity and mortality. Knowledge of local epidemiology and trends is important to inform practitioners of likely pathogens in the sick child. This study aimed to determine trends over time in pathogenic organisms causing paediatric bacteraemia in North Queensland and to audit a hospital's blood culture results with respect to contamination rate. This was a retrospective review of 8385 blood cultures collected from children attending a tertiary centre in North Queensland over a 10-year period (2001-2010). There were 696 positive blood cultures (8.3%) with 70 different bacterial species detected. Gram-positive and Gram-negative bacteria accounted for 48.6% and 51.4% of isolates, respectively. Overall, bacteraemia accounted for 4.7 per 1000 admissions. The rate of contamination was 60.6% among positive blood cultures and 5.0% for all blood cultures sampled. These results were compared with previous published reports. Notable differences were seen in the frequencies of Salmonella and group A Streptococcus bacteraemias in North Queensland when compared with other reports. There was also a decline in vaccine-preventable infections such as S. pneumoniae and an increasing trend of community-acquired MRSA bacteraemia. This study has demonstrated the unique profile of causative pathogens of paediatric bacteraemias in tropical Australia. In light of the increasing prevalence of MRSA, empiric treatment for sepsis for children in this region needs to be reconsidered.

Dynamics of methicillin-resistant Staphylococcus aureus and methicillin-susceptible Staphylococcus aureus carriage in pig farmers: a prospective cohort study

Our purpose was to determine the dynamics of livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) carriage and its determinants in persons working at pig farms, in order to identify targets for interventions. This prospective cohort study surveyed 49 pig farms in the Netherlands on six sampling dates in 1 year (2010-11). Nasal and oropharyngeal swabs were collected, as well as environmental surface samples from stables and house. Of 110 pig farmers, 38% were persistent MRSA nasal carriers. The average cross-sectional MRSA prevalence was 63%. Methicillin-susceptible S. aureus (MSSA) nasal carriage was associated with fewer MRSA acquisitions (prevalence rate (PR) = 0.47, p 0.02). In multivariate analysis, an age of 40-49 years (PR = 2.13, p 0.01), a working week of ≥40 h (PR=1.89, p 0.01), giving birth assistance to sows (PR=2.26, p 0.03), removing manure of finisher pigs (PR=0.48, p 0.02), and wearing a facemask (PR = 0.13, p 0.02) were significantly related with persistent MRSA nasal carriage. A higher MRSA exposure in stables was associated with MRSA in pig farmers (p <0.0001). This study describes a very high prevalence of LA-MRSA carriage in pig farmers, reflecting extensive exposure during work. We identified the possible protective effects of MSSA carriage and of continuously wearing a facemask during work.