Proportion Of MRSA Research Articles

Occurrence and Antimicrobial Susceptibility Profile of Vancomycin Resistance among Clinical Isolates of Staphylococcus aureus in Enugu Metropolis, Nigeria

Introduction: Staphylococcus aureus is a significant cause of community-acquired and healthcare-acquired infections worldwide. Methicillin-resistant Staphylococcus aureus infections have been treated with vancomycin, a last-resort antibiotic. This study aimed to investigate the occurrence of vancomycin resistance among Staphylococcus aureus isolates obtained from different clinical samples. Materials and Methods: The study was conducted from February to August 2022 in the Microbiology Laboratory of the University of Nigeria Teaching Hospital Ituku-Ozalla, Enugu. A total of 150 Staphylococcus aureus isolates from different clinical samples were used for the study. The antimicrobial susceptibility profile was done using the Kirby-Bauer disc diffusion procedure. Methicillin resistance was detected using the cefoxitin disc diffusion technique. VRSA was confirmed using the broth dilution method. Results: Isolates showed high resistance to cephalosporins; 100% resistance to cefixime, to cefotaxime 98.7%, to cefuroxime 93.3%, and to ceftriaxone 80%. There was also high resistance of isolates to imipenem 98.7%, Augmentin 92.2%, erythromycin, and azithromycin 81.3% and 80.0% respectively. Of the 150 isolates, 51(34.0%) were methicillin-sensitive Staphylococcus aureus (MSSA) and 99(66.0%) were MRSA. Of the 99 MRSA strains, 9 (9.1%) were vancomycin-resistant (VRSA), 24 (24.2%) were vancomycin intermediate (VISA) and 66 (66.7%) were vancomycin-sensitive (VSSA). The overall prevalence of VRSA was 6%. Conclusion: The isolates had a high resistance to the antibiotics used in our study. The proportion of MRSA was high. A high percentage of VRSA/VISA was also detected. To prevent the further spread of VRSA, rigorous monitoring of vancomycin treatment, response, and the development of appropriate control guidelines are strongly recommended and required.

Staphylococcus aureus: changes in antimicrobial sensitivity profile and its relationship with SCCmec among clinical isolates

Background and Objectives: Staphylococcus aureus is a pathogen of great clinical relevance, especially those resistant to methicillin, called MRSA. Over the years, S. aureus antimicrobial resistance patterns have changed. Understanding such changes is essential to update protocols and propose efficient therapeutic approaches. This study aimed to characterize the temporal distribution of S. aureus antimicrobial resistance in patients admitted to the hospital as well as to assess its relationship with SCCmec typing. Methods: a total of 9,949 cultures of clinical materials were analyzed, between January 2000 and October 2019, from patients admitted to a university hospital in southern Brazil. All isolates had their identification and antimicrobial sensitivity profile analyzed using manual and automated techniques. Furthermore, 86 isolates were selected for mecA gene research and SCCmec typing using conventional and multiplex PCR techniques, respectively. Results: when assessing the temporal distribution of S. aureus over 20 years, it was possible to observe a drop in the proportion of MRSA compared to methicillin-sensitive S. aureus (MSSA). Between 2000 and 2002, the frequency of MRSA was 58.5%, whereas that of MSSA was 36.7%. However, from 2003 onwards, there was a reversal of these percentages. At the end of the analyzed period, 55.2% of infections were caused by MSSA, whereas 36.2% contained MRSA isolates. Furthermore, in the period analyzed, the highest prevalence was of SCCmectype II. Conclusion: these data suggest an epidemiological change in S. aureus from clinical materials, with a change in the prevalent type of SCCmec and changes in the antimicrobial sensitivity profile exhibited by the isolates. Such facts must be considered by the clinical staff with a focus on effective patient management, the choice of appropriate antimicrobial therapy so that effective infection control measures are implemented.

Temporal trends of skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus in Gabon

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of mortality due to bacterial antimicrobial resistance. While S. aureus is common in skin and soft tissue infections (SSTI) in Africa, data on MRSA rates are scarce and reports vary widely across the continent (5%-80%). In this study, we describe the proportion of MRSA causing SSTI in Lambaréné, Gabon, over an 11-year period.MethodsWe retrospectively analyzed data from 953 bacterial specimens collected from inpatients and outpatients with SSTI at the Albert Schweitzer Hospital, Lambaréné, Gabon, between 2009 and 2019. We determined temporal changes in the prevalence of MRSA and identified risk factors for SSTI with MRSA.Results68% of all specimens with bacterial growth yielded S. aureus (n = 499/731), of which 7% (36/497) with antimicrobial susceptibility testing were identified as MRSA. Age above 18 years, admission to the surgical ward, and deep-seated infections were significantly associated with MRSA as the causative agent. After an initial decline from 7% in 2009, there was a marked increase in the proportion of MRSA among all S. aureus from SSTI from 3 to 20% between 2012 and 2019. The resistance rate to erythromycin was significantly higher in MRSA than in methicillin-susceptible S. aureus (73% vs. 10%), and clindamycin resistance was detected exclusively in MRSA isolates (8%).ConclusionThe increasing proportion of MRSA causing SSTI over the 11-year period contrasts with many European countries where MRSA is on decline. Continuous surveillance of MRSA lineages in the hospital and community along with antibiotic stewardship programs could address the increasing trend of MRSA.

Antimicrobial Resistance Pattern of Staphylococcus aureus Isolated from Skin and Soft Tissue Infection in Patients at a Tertiary Care Hospital, Southern India

Background Staphylococcus aureus is a highly virulent human pathogen known to cause various hospital acquired and community-acquired infections. S. aureus is capable of rapid evolutionary change needed to overcome obstacles including the effect of various antibiotics. The emergence of drug resistant strains i.e. MRSA and multidrug resistance is a cause of concern for the treatment of S. aureus infection. The main objective of the present study was to determine the distribution of S. aureus infection in the skin and soft tissue infections and its drug resistance pattern.Methods A total of 100 non-duplicate puswound swabs from 50 males and 50 females were collected from skin and soft tissue infections. Samples were processed by microscopy culture and identified by standard biochemical tests. Antimicrobial susceptibility testing for S. aureus was performed by Kirby-Bauer disk diffusion method. Methicillin resistant Staphylococcus aureus MRSA isolates were detected using cefoxitin disk 30 microg. The demographic details of patients were collected. The infection rate with S. aureus was assessed.Results Out of 100 non-duplicate isolates 77 were infected with S. aureus. Male patients showed higher rate of infection 90 compared to female patients 64. The rate of MRSA isolate was 49. All the MRSA isolates were 100 sensitive to vancomycin teicoplanin and linezolid.Conclusion A high rate of S. aureus infection 77 was seen among skin and soft tissue infections. The proportion of MRSA was 49. No resistance was detected for vancomycin teicoplanin and linezolid. Continuous surveillance should be conducted to check the development of antibiotic resistance rate and based on these reports antimicrobial stewardship policy should be made.

Epidemiology and antimicrobial susceptibility of Staphylococcus aureus in children in a tertiary care pediatric hospital in Milan, Italy, 2017—2021

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is highly prevalent worldwide and can cause severe diseases. MRSA is associated with other antibiotic resistance. COVID-19 pandemic increased antimicrobial resistance in adult patients. Only a few data report the antimicrobial susceptibility of S. aureus in the Italian pediatric population, before and during the COVID-19 pandemic.MethodsWe included all the S. aureus positive samples with an available antibiogram isolated from pediatric patients (< 18 years old) in a tertiary care hospital in Milan, Italy, from January 2017 to December 2021. We collected data on demographics, antimicrobial susceptibility, and clinical history. We compared methicillin-susceptible Staphylococcus aureus (MSSA) and MRSA strains. We calculated the frequency of isolation by year. The incidence of isolates during 2020 was compared with the average year isolation frequency using the univariate Poisson test. We compared the proportion of MRSA isolates during 2020 to the average proportion of other years with the Chi-squared test.ResultsOur dataset included a total of 255 S. aureus isolated from 226 patients, 120 (53%) males, and 106 (47%) females, with a median age of 3.4 years (IQR 0.8 – 10.5). The mean isolation frequency per year was 51. We observed a significant decrease of isolations during 2020 (p = 0.02), but after adjusting for the total number of hospitalization per year there was no evidence that the incidence changed. Seventy-six (30%) S. aureus were MRSA. Twenty (26%) MRSA vs 23 (13%) MSSA (p = 0.02) were hospital-acquired. MRSA strains showed higher resistance to cotrimoxazole, clindamycin, macrolides, levofloxacin, gentamicin, and tetracyclin than MSSA strains. None of MRSA were resistant to linezolid and vancomycin, one was resistant to daptomycin. The proportion of MRSA did not change during the COVID-19 pandemic. The overall clindamycin resistance was high (17%). Recent antibiotic therapy was related to MRSA infection.ConclusionThe proportion of MRSA did not change during the COVID-19 pandemic and remained high. Clindamycin should not be used as an empirical MRSA treatment due to its high resistance.

Vancomycin MIC creep progresses in methicillin-resistant Staphylococcus aureus despite the national antimicrobial stewardship campaign: Single facility data in Japan

BackgroundMethicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of nosocomial and community infections, and vancomycin (VCM) is widely recommended as a first-line therapeutic drug. Minimum inhibitory concentrations (MICs) of VCM ≤2 μg/mL are defined as susceptible, but increases in these levels, known as “VCM MIC creep” have been reported. The aim of this study was to investigate VCM MIC creep during the promotion of a national antimicrobial stewardship campaign. MethodsWe collected data from 2013 to 2020 on S. aureus isolated at the clinical microbiology laboratory at Okayama University Hospital, Japan. We calculated the annual proportions of MRSA isolation rates by MIC levels for nosocomial and community samples and estimated annual percentage changes in the antimicrobial use density of the VCM. ResultsOf the 1,716 MRSA isolates, no strains showed intermediate or resistant ranges of VCM MIC levels. By 2020, the proportion of MRSA with an MIC of ≤0.5 μg/mL decreased to 35.4%, while that with an MIC of 1 μg/mL increased to 64.1% over time. The annual percentage changes of the VCM antimicrobial use density significantly increased without any trend change point (average 8.1%, p = 0.035). There was no clear correlation between the VCM AUD and annual proportion of nosocomial MRSA with MIC 1 μg/mL (correlation coefficient 0.48; p value = 0.24). ConclusionWe demonstrated a deteriorating situation of VCM MIC creep among MRSA strains isolated at our university hospital during the national antimicrobial stewardship campaign.

ESTIMATE THE PROPORTION OF MRSA AMONG STAPHYLOCOCCUS AUREUS ISOLATED FROM PATIENTS OF URINARY TRACT INFECTION ALONG WITH ITS ANTIBIOGRAM IN TERTIARY CARE HOSPITAL AT AGARTALA, TRIPUR

Background: Generally, gram-negative bacteria are the most common uropathogenic bacteria causing UTI, as per recent ndings gram-positive bacteria also equally responsible for the UTI. As they have a plethora of pathogenic virulence factors that are highly responsible to give rise to severe UTI infection. Moreover, a betalactamase-producing gram-positive organism such as Staphylococcus aureus is often associated with high resistance to a wide class of antibiotics. There are few studies regarding the UTI infection-causing by the multi-drug resistant strain of Staph aureus called MRSA in Tripura Northeast India. This study aimed to determine the proportion of MRSA causing UTI in Tertiary care hospitals at Agartala Tripura. Materials and method – Mid-stream urine specimens were collected from patients suspected to be having UTI. Well, the mixed sample of urine was inoculated on specic culture media and all the isolates were identied as staphylococci by Gram staining, catalase test, coagulase test, and other biochemical reactions required for the identication of S.aureus and as per the CLSI guidelines we have studied the antibiogram of S.aureus and we have detected the MRSA by cefoxitin disc diffusion method. Result: in our present study 650 midstream urine samples were collected and processed. Out of the total 650 urine samples 91(14%) yielded growth on culture media and out of the 91 positive cases Staphylococcus aureus infected UTI cases were 12(13%) and among the 12 S.aureus positive isolates 6(50%) isolates were MSSA and other 6(50%) isolates were MRSA. Here in our study vancomycin(100%), doxycycline(83%), Nitrofurantoin(100%), Linezolid(83%) found to be very effective drugs for the treatment of MRSA, and most importantly here in this region of northeast only 6.5% of the total UTI patients affected by the MRSA which means the ratio of UTI infection by MRSA is low in this region. CONCLUSION: This study will be useful to update the policy of the empirical drugs in our hospital and at the same time, it will also help to control the unnecessary use of antibiotics to treat UTI patients

Are resistance rates among bloodstream isolates a good proxy for other infections? Analysis from the BSAC Resistance Surveillance Programme.

Bacteraemia data are often used as a general measure of resistance prevalence but may poorly represent other infection types. We compared resistance prevalence between bloodstream infection (BSI) and lower respiratory tract infection (LRTI) isolates collected by the BSAC Resistance Surveillance Programme. BSI isolates (n = 8912) were collected during 2014-18 inclusive and LRTI isolates (n = 6280) between October 2013 to September 2018 from participating laboratories in the UK and Ireland, to a fixed annual quota per species group. LRTI isolates, but not BSI, were selected by onset: community for Streptococcus pneumoniae; hospital for Staphylococcus aureus, Pseudomonas aeruginosa and Enterobacterales. MICs were determined centrally by agar dilution; statistical modelling adjusted for ICU location and possible clustering by collection centre. Resistance was more prevalent among the LRTI isolates, even after adjusting for a larger proportion of ICU patients. LRTI P. aeruginosa and S. pneumoniae were more often resistant than BSI isolates for most antibiotics, and the proportion of MRSA was higher in LRTI. For S. pneumoniae, the observation reflected different serotype distributions in LRTI and BSI. Relationships between LRTI and resistance were less marked for Enterobacterales, but LRTI E. coli were more often resistant to β-lactams, particularly penicillin/β-lactamase inhibitor combinations, and LRTI K. pneumoniae to piperacillin/tazobactam. For E. cloacae there was a weak association between LRTI, production of AmpC enzymes and cephalosporin resistance. Estimates of resistance prevalence based upon bloodstream isolates underestimate the extent of the problem in respiratory isolates, particularly for P. aeruginosa, S. pneumoniae, S. aureus and, less so, for Enterobacterales.

The Pattern of Microorganisms and Drug Susceptibility in Pediatric Oncologic Patients with Febrile Neutropenia

Objective The study aimed to describe the pattern of causative microorganisms, drug susceptibility, risk factors of antibiotic-resistant bacterial infection, and clinical impact of these organisms on pediatric oncology patients with febrile neutropenia. Methods A retrospective descriptive study of oncologic patients aged less than 15 years who were diagnosed with febrile neutropenia in King Chulalongkorn Memorial Hospital was conducted between January 2013 to December 2017. Characteristics and clinical outcomes of febrile neutropenia episodes, causative pathogens, and their antibiotic susceptibilities were recorded. Result This study included 267 patients with 563 febrile neutropenia episodes. The median (range) age was 5.1 years (1 month–15 years). The most common underlying disease was acute lymphoblastic leukemia (42.7%). Of 563 febrile episodes, there were 192 (34.1%) with microbiologically documented infection. Among these 192 episodes of microbiologically documented infection, there were 214 causative pathogens: 154 bacteria (72%), 32 viruses (15%), 27 fungus (12.6%), and 1 Mycobacterium tuberculosis (0.4%). Gram-negative bacteria (48.6%) accounted for most of the causative pathogens. Twenty-three percent of them were multidrug resistant, and 18% were carbapenem resistant. Among Gram-positive bacterial infection which accounted for 23.4% of all specimens, the proportion of MRSA was 20%. The 2-week mortality rate was 3.7%. Drug-resistant Gram-negative bacterial infection caused significant adverse events and mortality compared to nonresistant bacterial infection (p < 0.05). Conclusion There is high rate of drug-resistant organism infection in pediatric oncology patients in a tertiary-care center in Thailand. Infection with drug-resistant Gram-negative bacterial infection was associated with significant morbidity and mortality. Continuous surveillance for the pattern of drug-resistant infections is crucial.

Bloodstream Infection Etiology among Children and Adults.

Every year in the world, sepsis occurs in 31.5 million people, and the number of deaths reaches 5.3 million per year. There are not enough studies that describe etiological structure of sepsis pathogens in different groups of population of the Republic of Kazakhstan. In this study, we have investigated difference of local sepsis etiology and antibiotic susceptibility among children and adults. A total 200 blood samples were examined using the standard and express method of identification of bloodstream pathogens. The determination of antimicrobial sensitivity was carried out by the disc-diffusion method according to CLSI guidelines. Overall, 23/90 (25.5%) positive blood cultures were isolated from adult patients and 43/110 (39%) from pediatric patients. It was found that children are statistically more often affected with bacterial bloodstream infection than adults (p < 0.05). The Gram-positive bacteria are the leading cause of sepsis in both groups: S. epidermidis (35.5%) in pediatric patients and S. aureus (21.7%) in adults. However, statistical significance was detected in pediatric patients (p < 0.05). The number of resistant strains of S. epidermidis (MRSE) in the group of children was 66.7%, while in adults, all S. epidermidis was resistant to azithromycin and cefoxitin (MRSE). S. aureus strains from adult patients and children had a similar picture of antibiotic patterns. The proportion of MRSA in pediatric patients was 16, 6%, and in adult patients, 20%. Enterobacterales (39%) were the second cause of sepsis in adult patients. 62.5% of Enterobacterales strains isolated from adults were phenotypically identified as ESBL, while in pediatric patients, 25% of ESBL producers were isolated. We have noted the resistance to antibiotics that are prescribed according to protocols of treatment of the Republic of Kazakhstan in the strains isolated from the patient's blood.

Monitoring of antibiotic resistance in problem microorganisms in patients with purulent wounds

Objective: to study changes in the resistance of problem microorganisms to antibacterial drugs in patients with purulent wounds. Material and methods. On the basis of a bacteriological laboratory, within 2006-2007 and 2019-2020, 92 and 99 patients with purulent wounds of various locations, respectively, were examined by the standard bacteriological methods. Results. For the past 13 years, significant changes have occurred in the etiological structure of gram-negative problem microorganisms in patients with purulent wounds. Reliably significant increases were found in the share of K. pneumoniae - about 8 times, and A. baumannii - about 9 times. However, the proportion of MRSA has not changed. The most effective drugs for MRSA were vancomycin, linezolid, tigecycline - 0 % of resistant isolates; for K. pneumoniae - colistin (0 %), tigecycline (8.33 %); for P. aeruginosа - colistin (0 %), doripenem (45.45 %); for A. baumannii - ampicillin + sulbactam (0 %), colistin (0 %). Conclusions. For infections caused by MRSA , glycopeptides (vancomycin) should be recommended as the drug-of-choice, and the reserve drugs - oxazolidinones (linezolid) and glycylcyclins (tigecycline); K. pneumoniae - colistin and tigecycline; P. aeruginosa - carbapenems (doripenem) and colistin; A.baumannii - penicillins or cephalosporins with sulbactam (ampicillin + sulbactam) and colistin.

Staphylococcus aureus nasal carriage among healthcare workers, inpatients and caretakers in the Tamale Teaching Hospital, Ghana

BackgroundStaphylococcus aureus associated nosocomial infection is an important health challenge as isolates may involve multidrug resistant strains. Sources of S.aureus infection in healthcare settings include colonized healthcare workers, inpatients, and caretakers. This study investigates S. aureus carriage rate and associated antimicrobial resistance among healthcare workers, inpatients, and caretakers in the Tamale Teaching Hospital (TTH), Ghana. MethodsNasal swabs and demographic data were collected from a cross-section of healthcare workers, inpatients, and caretakers. The swabs were culture and S. aureus isolates subjected to antibiotic susceptibility assay. ResultsResults: S. aureus nasal carriage rate was 25.5% (27/106) while MRSA and non-MRSA prevalence were 8.5% (9/106) and 17.0% (18/106) respectively. The proportion of S. aureus carriage distribution was highest among neonates 42.1% (8/19), follow by participant in the age group 11–20 years, 36.8% (7/19). Inpatients, healthcare workers, and caretakers recorded S. aureus carriage rate of 30.0% (15/50), 27.8% (10/36), and 10% (2/20), respectively. Healthcare workers had the highest proportion of MRSA 40% (4/10) and inpatients recorded a rate of 33.3% (5/15), while no case of MRSA was recorded among caretakers. Antibiotic resistance pattern of the isolates was generally higher in MRSA compared to non-MRSA. ConclusionsThere exist relatively high rate of S. aureus nasal carriage among healthcare workers, inpatients, and caretakers in the wards/units of the TTH. However, MRSA were only isolated from healthcare workers and inpatients but not caretakers.

MICROBIAL COMPOSITION OF PURULENT LESIONS IN PATIENTS WITH COMPLICATED DIABETIC FOOT SYNDROME

Bacterial infection is a major pathogenetic aspects in the formation of diabetic foot complications. Joining infection is the cause of performing amputations of the lower limbs in 25-72 % of cases, especially when diabetic foot is complicated by sepsis. The aim of our study was to identify differences in the microbial background of purulent foci in patients with diabetic foot syndrome complicated by sepsis and for the further development of the algorithm of directed antibiotic therapy. Material and methods. A total of 3653 patients in the dynamics of a complicated diabetic foot syndrome were examined. There were two groups: the first - patients who were treated during 2010-2014 (a comparison group), the second – during 2015-2019 (main group), which according to the gender ratio (χ2=0.09; P=0.7698) and age (P=0.17141) did not differ. The complex bacteriological studies consisted of determining the sensitivity of microorganisms to antibiotics, the qualitative composition of microbial pathogens and the number of microbial cells per 1 g of tissues. To determine the sensitivity of purulent microorganisms to antibiotics a quick method of determination on automated systems «Vitek-2» and «BacT/ ALERT» (France) was applied. Results and discussion. All patients with complicated diabetic foot syndrome were operated under general anesthesia. As a rule, operations on the anterior foot and «high» amputations were performed. 190 people died, death rate was 5.2 %. The analyzed data indicate that in patients with diabetic foot syndrome complicated by the number of microbial cells in tissue 1g to the site of infection did not exceed 105 – 106, while in patients with sepsis, this number was more than 50% was 107 – 1012. Isolation of aerobic monoinfection of purulent foci in patients with complicated diabetic foot syndrome in the period from 2010 to 2019 decreased from 51,4 to 44,4% (P &lt;0,05) determined by an increase in the allocation of gram-positive microorganisms from 55,2 to 60,2% (P&lt;0,05). The dynamics of microbiological research indicates an increase in the proportion of MRSA- staphylococci from 23,4 to 43,3 %. Determined microbial pathogens are characterized by a high level of antibiotic resistance, particularly to antibiotic-I-II generation. Conclusions. These experiments enable to distinguish particularly microbial background of purulent foci of the two groups of patients and determine antibiotic algorithms.

554. The Changing Epidemiology of Methicillin-Resistant Staphylococcus aureus Causing Bacteremia in Hiroshima, Japan During 2008–2017

BackgroundRecently, the Japanese intrinsic community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) clone (CA-MRSA/J), classified as sequence type (ST) 8 carrying staphylococcal cassette chromosome mec (SCCmec) type IVl (ST8-IVl), has been identified that causes invasive infections similar to those of USA300 clone. However, epidemiological information regarding epidemic CA-MRSA clones is limited in Japan. This study was performed to investigate the changing epidemiology of MRSA causing bacteremia in Japan.MethodsWe performed whole-genome sequencing of MRSA isolates causing bacteremia at Hiroshima University Hospital between January 2008 and December 2017. MRSA isolates were subjected to multilocus sequence typing, SCCmec typing and were analyzed for virulence factors. Clinical data of patients with MRSA bacteremia were analyzed.ResultsA total of 193 MRSA strains causing bacteremia were identified during the study period. Among these, most belonged to ST764-IIa (30%; 59 of 193) and ST5-IIa (26.9%; 52 of 193). The proportion of ST5-IIa MRSA decreased from 39.6% (42 of 106) in 2008–2012 to 11.5% (10 of 87) in 2013–2017, and that of ST764-IIa MRSA increased from 23.6% (25 of 106) to 39.1% (34 of 87) in the same time period. The proportion of CA-MRSA (MRSA carrying SCCmec type IV or V) increased from 28.3% (30 of 106) in 2008–2012 to 42.5% (37 of 87) in 2013–2017. In CA-MRSA strains, clonal complex (CC) 8-IV MRSA was predominant (76.1%; 51 of 67). Those belonging to CC8-IV MRSA isolates were ST380-IVc (18 of 51), ST8-IVl (CA-MRSA/J; 15 of 51), ST8-IVj (15 of 51), ST8-IVa (2 of 51), and ST4803-IVl (1 of 51). The rate of hospital-onset infections of ST380-IVc, ST8-IVl, and ST8-IVj were 83.3%, 46.7%, and 60%, respectively. In CA-MRSA/J strains, including their variants (e.g., ST4803-IVl), 14 of 16 strains (87.5%) carried genes for toxic shock syndrome toxin (tst-1), enterotoxin C (sec), and enterotoxin L (sel), while none of the ST380-IVc and ST8-IVj MRSA strains carried these genes.ConclusionDuring the study period of 10 years, predominant ST5-IIa MRSA causing hospital-onset infections was replaced by ST764-IIa MRSA. In CA-MRSA clone, ST380-IVc, ST8-IVl (CA-MRSA/J), and ST8-IVj were dominant and have already spread to the healthcare environment.Disclosures All authors: No reported disclosures.

Staphylococcus aureus from hospital-acquired pneumonia from an Italian nationwide survey: activity of ceftobiprole and other anti-staphylococcal agents, and molecular epidemiology of methicillin-resistant isolates.

To determine the prevalence of Staphylococcus aureus from hospital-acquired pneumonia (HAP) in Italy and the susceptibility to ceftobiprole and comparators of MSSA and MRSA isolates. A secondary objective was to characterize the clonality and acquired resistance and virulence genes of MRSA. Consecutive non-replicate isolates from HAP were collected from 13 laboratories distributed across Italy, from January to May 2016. Antimicrobial susceptibility testing was performed by broth microdilution, and results were interpreted according to the EUCAST breakpoints. All MRSA isolates were subjected to WGS using an Illumina platform. Clonality and resistance and virulence gene content were investigated with bioinformatics tools. Among 333 isolates from HAP, S. aureus was the third most common pathogen (18.6%). The proportion of MRSA was 40.3%. Susceptibility to ceftobiprole was 100% for MSSA and 95.5% for MRSA. Lower susceptibility rates of 78.4% and 94.6% in MSSA and 36.4% and 12.1% in MRSA isolates were observed for erythromycin and levofloxacin, respectively. The MRSA from HAP mostly belonged to clonal complex (CC) 22 (47.0%), CC5 (25.8%) and CC8 (15.2%), with a minority of other lineages (ST1, ST6, ST7, ST30, ST152 and ST398). Acquired resistance and virulence genes in most cases exhibited a clonal distribution. The three ceftobiprole-resistant isolates exhibited an MIC of 4 mg/L and belonged to ST228-MRSA-I of CC5. S. aureus is an important cause of HAP in Italy. Ceftobiprole exhibited good in vitro activity against S. aureus isolated from HAP, including MRSA. A trend to replacement of ST228 with ST22 was noticed compared with previous studies.

Study of the virulence factors and antimicrobial susceptibility profile of staphylococcus aureus isolated from clinical samples at tertiary care centre

Introduction: Staphylococcus aureusis an important cause of healthcare-associated infections. The increasing resistance of this pathogen to various antibiotics complicates treatment. Present study was conducted to isolate staphylococcus aureus from various clinical samples, to study the few virulence factors, antibiogram and to detect methicillin resistance among them. Materials and Methods: Present study was done over a period of six months. The study was conducted on 100 staphylococcus aureus isolated from various clinical samples. The organisms were identified as per standard conventional methods. The antibiotic sensitivity testing of the isolates was done by Kirby Bauer’s Disk Diffusion method according to CLSI guidelines. These strains were screened for DNase production, beta hemolytic property and slime production. Results: Among 100 clinical isolates of staphylococcus aureus 82% of them showed beta hemolysis, 79% produces DNase, 72% produces slime. The proportion of MRSA amongst S. aureus isolates was found to be 53%. MSSA were 100% sensitive to vancomycin and linezolid85.10 % to Doxycycline, 82.98% to clindamycin, 72.34% to chloramphenicol, 68.09% Co- trimoxozole, 65.95% to erythromycin, 61.70% gentamicin, 51.06 % to Ciprofloxacin, 12.77% topenicillin. MRSA were 100% sensitive to vancomycin and linezolid, 71.69% Doxycycline, 64.15% to Chloramphenicol, 60.37% to Clindamycin, 43.39% to Ciprofloxacin, 39.62% Gentamicin, 37.74% Co- trimoxozole, 35.84% to Erythromycin and all the isolates were resistant to penicillin. Conclusion: Understanding of virulence mechanisms and antibiotic susceptibility pattern of Staphylococcus aureus is important for effective management of infections.

2149. Real-Time Nationwide Surveillance for Antimicrobial Resistance of Major Pathogens Using Automated Data Collection System in Korea: A KARS-Net Study

BackgroundInformation on the most current status of antimicrobial resistance (AMR) in local and national levels has critical importance. However, collection and analysis of a large number of antimicrobial susceptibility test (AST) results often results in additional workload in healthcare facilities and latency in final reporting. We sought to develop an automated nationwide surveillance network in Korea.MethodsData collection servers were set up at each participating institutions, which collects AST results of every bacterial isolate from blood, cerebrospinal fluids, urine, and respiratory specimens. Collected results are anonymized and transmitted to central data server every day without human input. End-user can perform various analyses using data warehouse server through web interface. Only first isolates of same species from individual patients were included in analysis.ResultsA total of 19 hospitals located in various regions in Korea participated to the network. From January 2015 through December 2017, AST results of 347,356 isolates were collected. The proportion of MRSA among S. aureus (n = 17,761) was 65.3%, which declined gradually from 71.5 to 62.3% during study period (P < 0.001). The proportion of VRE increased from 29.3 to 36.3% (P = 0.001). Resistance rates of E. coli (n = 63,628) to third and fourth generation cephalosporins, fluoroquinolone, and piperacillin–tazobactam were 31.6, 23.0, 44.0, and 4.2%, respectively. Resistance rates of K. pneumoniae (n = 16,875) to same classes were 32.2, 28.1, 31.0 and 19.1%, respectively. Among E. coli and K. pneumoniae, 0.4 and 4.3% were resistant to carbapenem. Resistance rates of P. aeruginosa (n = 12,895) to carbapenem was 30.5%. However, 72.7% of A. baumannii isolates (n = 9,885) were resistant to carbapenem. Colistin resistance rate was still low at 0.5%.ConclusionWe have established a fully automated nationwide surveillance network for AMR in Korea. Our system provided data on the most current status of AMR, which revealed increase in resistance rates among major Gram-negative pathogens compared with previous studies.Figure 1.Schematic diagram of the Korean Antimicrobial Resistance Surveillance Network (KARSNet).Figure 2.Temporal trends of the resistance rates of S. aureus and E. faecium.Figure 3.Temporal trends of the resistance rates of major Gram-negative species.Disclosures All authors: No reported disclosures.

Bacteriological study of community-acquired pyoderma with special reference to methicillin-resistant Staphylococcus aureus

Background: Pyoderma is one of the most frequently encountered condition in dermatology clinics in India. Staphylococcus and Streptococcus are the most common causative agents. There is considerable variation in the reported antibiotic susceptibility pattern of the organisms isolated from pyoderma with a trend toward increasing resistance. Objectives: The objectives of this study were (1) to study the clinical patterns of cutaneous bacterial infections, (2) to determine the antibiotic sensitivity of the isolates obtained, and (3) To assess the prevalence of methicillin resistance (methicillin-resistant Staphylococcus aureus [MRSA]) among the community–acquired (CA) pyoderma. Materials and Methods: Two hundred and fifty-six patients of CA pyoderma constituted the study population. A detailed history was taken and thorough clinical examination was performed. Gram-stained smear examination and culture and sensitivity test of pus were done. Results: Primary pyoderma was seen in 48.8% and secondary pyoderma in 51.2% of cases. The most common primary pyoderma was folliculitis (52%) followed by furuncle (25.6%). In secondary pyoderma, the most common condition was infected eczema (38.2%) followed by infected ulcers (22.1%). Staphylococcus was isolated in 87.5%, Streptococcus in 2%, and mixed organisms were isolated in 5.5% of cases. Maximum susceptibility was seen to tigecycline (89.1%) and linezolid (88.3%). Among topical antibiotics, mupirocin was susceptible in 75.8% and fusidic acid in 66.4% of the organisms. The highest resistance was seen to benzylpenicillin in 81.6% followed by ciprofloxacin in 53.1% of the organisms. The least resistance was seen for daptomycin in 0.8%, tigecycline in 1.6%, linezolid in 2.3%, and mupirocin in 2.7% of the organisms. The proportion of MRSA in CA pyodermas was 25.5%. Conclusion: The study yielded some useful epidemiological and clinicobacteriological data about CA pyoderma. The above observations made regarding antibiotic sensitivities may assist clinicians in choosing antibiotics for CA pyoderma in the absence of pus culture sensitivity.

Study on the antibiotic resistance of Staphylococcus aureus isolated from hospitalized children with respiratory tract infections

Objective To investigate the antimicrobial resistance and genotype distribution of staphylococcal cassette chromosome mec(SCCmec) of staphylococcus aureus(S.aureus) isolated from children hospitalized at Pediatric People′s Hospital of Zhongjiang County. Methods Seventy-seven strains of S. aureus were collected by nasopharyngeal swabs at the Pediatric Department of People′s Hospital of Zhongjiang County from January to December 2015.Methicillin-resistant staphylococcus aureus (MRSA) and methicillin-susceptible staphylococcus aureus (MSSA) were identified by cefoxitin disc diffusion and detection of mecA method.The minimum inhibitory concentrations(MIC)of antibiotics were determined by E-test method.SCCmec typing on MRSA strains was performed by using multiplex PCR. Results MRSA accounted for 54.5% (42 strains) strains of 77 strains.All MRSA strains were resistant to Pe-nicillin, and the rates of antibiotic resistance to Cefuroxime, Ceftriaxone, Erythromycin were 78.6%, 95.2% and 97.6%, respectively.The rates of antibiotic resistance of 35 MSSA to Penicillin and Erythromycin were 97.1% and 62.9%, and they were also sensitive to other antibiotics.In 42 strains of MRSA, SCCmec type Ⅳa was the predominant type(27 strains, 64.3%), which was followed by type Ⅳg and Ⅴ(each 5 strains, 11.9%), type Ⅳc and Ⅳh(each 1 strain, 2.4%). Non-susceptibility rate of SCCmec Ⅳ to cefuroxime was significantly higher than that of other SCCmec types(P<0.05). Conclusions All strains from children hospitalized in People′s Hospital of Zhongjiang County are often resistant to Penicillin and Erythromycin.The proportion of MRSA isolated from hospitalized children was high.SCCmec type Ⅳa is the main genotype of MRSA. Key words: Staphylococcus aureus; Methicillin-resistant Staphylococcus aureus; Staphylococcal cassette chromosome mec; Antibiotic resistance

A comparison of the recoverable proportion of methicillin-resistant Staphylococcus aureus from two different types of papers.

Aim: Paper is used for various purposes in hospitals. Generally, there are two different types of paper, which are commonly used in our facility: wood-free paper, and paper containing wood. We compared the recoverable proportion of methicillin-resistant Staphylococcus aureus (MRSA; ATCC 43300) from the surface of such papers. Method: The papers were divided into two groups: Group 1: wood-free paper; Group 2: paper containing wood. The papers were contaminated in a standardized procedure with 0.1 mL of a 5×107 CFU MRSA/mL stock solution. Results: The recoverable proportion of MRSA was higher in the wood-containing papers than in the papers without wood (P=0.043). Conclusion: This study indicates that if paper is purchased for healthcare facilities it should not contain wood, but rather wood-free paper types should be considered.