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    Distribution of emm Genotypes and Antibiotic Susceptibility of Streptococcus pyogenes Strains: Analogy with the Vaccine in Development
    (ANKARA MICROBIOLOGY SOC, 2013) Arslan, Ugur; Oryasin, Erman; Eskin, Zeynep; Turk Dagi, Hatice; Findik, Duygu; Tuncer, Inci; Bozdogan, Bulent
    Streptococcus pyogenes is the most common bacterial pathogen causing pharyngotonsillitis, and also can lead to diseases such as otitis media, impetigo, necrotizing fasciitis, bacteremia, sepsis and toxic shock-like syndrome. M protein encoded by emm gene is an important virulence factor of S.pyogenes and it is used for genotyping in epidemiological studies. The aims of this study were to determine the M protein types of group A streptococci (GAS) by using emm gene sequence analysis method, to compare the M types in terms of analogy with the vaccine in development and to determine the antibiotic susceptibilities of the isolates. A total of 35 GAS strains isolated from various clinical specimens in our laboratory were included in the study. Strains growing in blood culture were considered as invasive, strains growing in throat and abscess cultures were considered as non-invasive. The isolates have been identified by conventional methods and 16S rRNA sequence analysis at species level. emm genotyping of strains identified as S.pyogenes, was performed by PCR method as proposed by the CDC. Amplicons were obtained and sequenced in 23 out of 35 isolates. The results were compared with CDC emm sequence database. Antibiotic susceptibility of the isolates was performed by agar dilution method and evaluated as recommended by CLSI. Twenty-three out of 35 isolates could be typed and 15 different emm genotypes were detected. The most common emm types were emm1 (22%), emm89 (13%), emm18 (9%) and emm19 (9%). The detection rate of other emm types (emm5, 12, 14, 17, 26, 29, 37, 74, 78, 92, 99) was 47%. Types emm1, 12, 19, 74, 89 and 99 were observed in strains isolated from blood cultures. It was detected that nine of the 15 (60%) emm types are within the contents of 26 valent vaccine (emm 1, 5, 12, 14, 18, 19, 29, 89, 92). It was also observed that 17 (74%) of the 23 cases were infected by vaccine types and the four emm types (emm1, 12, 19, 89) identified in blood samples were among the vaccine types. All of the strains were found susceptible to penicillin, ampicillin, erythromycin, lincomycin, gentamicin, chloramphenicol, vancomycin and linezolid, however six isolates were resistant to levofloxacin (MIC=4 and 16 mu g/ml) and one isolate was resistant to tetracycline (MIC= 16 mu g/ml). In conclusion, this preliminary local study with limited number of invasive and non-invasive S.pyogenes isolates, emphasized the need for larger scale multi-center studies to determine the analogy and efficacy of the vaccine in development.
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    Investigation of Various Virulence Factors of Klebsiella pneumoniae strains Isolated from Nosocomial Infections
    (ANKARA MICROBIOLOGY SOC, 2017) Kus, Halit; Arslan, Ugur; Turk Dagi, Hatice; Findik, Duygu
    Klebsiella pneumoniae is an opportunistic pathogen that commonly affects immunosuppressed patients and causes nosocomial infections. K. pneumoniae has a variety of virulence factors, especially capsule polysaccharide, hypermucoviscosity (HV), fimbriae, toxins and determinants for iron acquisition. The aim of this study was to detect the virulence factors in K. pneumoniae strains isolated from nosocomial infections in two years. Fifty three K. pneumoniae strains isolated from the samples of patients with nosocomial infections in the Medical Microbiology Laboratory of Selcuk University Faculty of Medicine Hospital between 2011 and 2013 were included in the study. Identification and antimicrobial susceptibilities of the isolates were performed by VITEK 2 automatic system. Biofilm formation, alpha-hemolysin, capsule and HV were investigated by phenotypic methods. Polymerase chain reaction (PCR) was used to detect virulence genes encoding adhesins (fimH-1, mrkD, kpn, ycfM), siderophores (entB: enterobactin, iutA: aerobactin, irp-1, irp-2, ybtS, fyuA: yersiniabactin, iroN: catechols receptor), protectines or invasins (rmpA, magA, traT) and toxins (hlyA, cnf-1). Of the 53 K. pneumoniae isolates, 12 (22.6%) were isolated from in patients of reanimation intensive care unit, 8 (15.1%) medical oncology, 7 (13.2%) newborn intensive care unit and 26 (49%) other clinics. The distribution of the isolates according to the samples was as follows: urine (n=14), blood (n=13), wound (n=8), drainage fluid (n=10), broncho-alveolar lavage (n=7), and cerebrospinal fluid (n=1). Isolates which were resistant to meropenem were 5.7% and production of extended spectrum beta-lactamase (ESBL) was 71.7%. The capsule, biofilm formation, and HV were observed in 100%, 79.2%, and 1.9% of the isolates, respectively. Production of alpha-hemolysin was not detected in any of the isolates. The genes; entB (96.2%), ycfM (86.8%), and mrkD (83.0%) showed high prevalence. The other genes were detected in different ratios: fimH-1 (64.2%), fyuA (54.7%), kpn (49.1%), ybtS (41.5%), irp-1(41.5%), irp-2 (37.7%), traT (11.3%) and iutA (5.7%). Virulence genes; iroN, rmpA, magA, hlyA and cnf-1 were not detected in any of the isolates. Enterobactin had the highest rate among siderophores, and ycfM and mrkD in adhesins. The capsule and biofilm formation were commonly found in the isolates. Hypermucoviscosity was only found in one isolate but associated genes were not detected. Alfa hemolysin production and hlyA gene were not determined. As a result, it seems that the basis of the pathogenicity of K. pneumoniae strains isolated from nosocomial infections are capsule, adhesins, enterobactin and ability of biofilm formation. There is a need for new studies for the continuous monitoring of toxin and invasion ability as well as antibiotic resistance in the control of hospital infection caused by K. pneumoniae.