[Investigation of Streptococcus pyogenes virulence factors and typing by multiple locus variable number tandem repeat fingerprinting (MLVF) method]. / Streptococcus pyogenes izolatlarinin virülans faktörlerinin arastirilmasi ve "multiple locus variable number tandem repeat fingerprinting (MLVF)" yöntemi ile tiplendirilmesi.

Streptococcus pyogenes is an important bacterial pathogen that colonizes the throat and skin of human beings and causes a wide variety of diseases ranging from mild infections like pharyngitis, tonsillitis and impetigo to severe invasive infections such streptococcal toxic shock syndrome, septicemia, and necrotizing fasciitis, and produces a wide variety of virulence factors. The aim of this study was to investigate the antibiotic resistance, virulence genes; [pyrogenic exotoxin genes (speA, C, G, H, I, J, K, L, M, smeZ and ssa), deoxyribonuclease genes (sdaB, spd3, sdc ve sdaD), protease genes (speB, spyCEP ve scpA) and inhibitor genes (mac and sic)] of S.pyogenes strains isolated from throat cultures of patients with symptomatic tonsillo-pharyngitis and typing by multiple locus variable number tandem repeat fingerprinting (MLVF) method. One hundred and fifty S.pyogenes isolates were identified by conventional methods and streptococcus group A latex kit (Biomerieux, France). Antibiotic susceptibility tests were performed by Kirby-Bauer disk diffusion method as recommended by Clinical and Laboratory Standards Institute. DNA isolation was performed by using a commercial DNA isolation kit (Qiagen, Germany) in accordance with manufacturer's recommendations. The virulence genes were determined by multiplex PCR. MLVF method was performed with multiplex PCR using specific primers for repeated sequences within bacterial genome. All of the S.pyogenes isolates were susceptible to penicillin G, cefotaxime, ceftriaxone, chloramphenicol, clindamycin, erythromycin, levofloxacin, vancomycin and linezolid. Among streptococcal pyrogenic exotoxin genes the most frequent gene was smeZ (90.0%) followed by speG (88.0%), speC (58.7%), ssa (42.7%), speA (33.3%), speJ (24.0%), speK (18.7%), speH (14.0%), speI (13.3%), speL and speM (9.3%). Of the DNase genes, sdaB was detected in all strains (100%), spd3, sdc, sdaD genes were determined as 64.7%, 36.0%, 24.7% respectively. Protease genes (speB, spyCEP, scpA) and mac gene from the inhibitor genes were positive in all strains, and sic gene was positive in only 3 (2.0%) of the isolates. Thirty-two different patterns that contained two or more isolates were determined by MLVF analysis. Ninety one isolates were included in any of the 32 different patterns, while 59 isolates were defined as sporadic isolates. In conclusion, S.pyogenes isolates collected from throat cultures of patients with symptomatic tonsillo-pharyngitis in Konya/Turkey were susceptible to all antibiotics studied and have carried a very high rate of virulence factors. However the isolates were mostly clonally unrelated and sporadic. This study is the first report in Turkey, in which S.pyogenes isolates were typed by the MLVF method and a large number of virulence factors were investigated.

[Investigation of OXA type beta-lactamases and PFGE patterns in Acinetobacter baumannii strains resistant to carbapenems]. / Karbapenemlere dirençli Acinetobacter baumannii suslarinda OXA tipi beta-laktamazlarin arastirilmasi ve PFGE ile genotiplendirilmesi.

Acinetobacter baumannii is an important opportunistic and multidrug-resistant pathogen leading to nosocomial infections. Over the last 10 years, a significant and threatening increase in resistance to carbapenems, mainly due to the dissemination of class D beta-lactamases, has been reported in A.baumannii worldwide. The most common types of beta-lactamases causing carbapenem resistance in A.baumannii are the OXA-23, OXA-24, OXA-40, OXA-58 and OXA-143 type serine beta-lactamases. The aim of this study was to investigate the presence of OXA type beta-lactamases in carbapenem-resistant A.baumannii strains and the clonal relationship between the strains. A total of 105 non-duplicate carbapenem-resistant A.baumannii strains isolated from various clinical samples (68 blood, 18 bronchoalveolar lavage, 13 drainage, 3 urine, 2 cerebrospinal fluid and 1 catheter samples) in the Microbiology Laboratories of Selcuk University, Meram (2009-2012) and Selcuklu (2007-2008) Medical School Hospitals, were included in the study. The isolates were identified by conventional methods and Phoenix 100 BD (BD Diagnostic, USA) and Vitek II (bioMerieux, France) automated systems. Carbapenem susceptibility test was performed by Kirby-Bauer disk diffusion method according to the CLSI standards. bla(OXA 23-like), bla(OXA 24-like), bla(OXA 58-like) and bla(OXA 51-like) genes were amplified by multiplex PCR assay and clonal relatedness was investigated by pulsed-field gel electrophoresis (PFGE) using ApaI enzyme. The bla(OXA 51-like) gene was determined in all carbapenem-resistant A.baumannii isolates, while the bla(OXA 23-like) and bla(OXA 58-like) genes were detected in 46.6% and 53.3% of isolates, respectively. However bla(OXA 24-like) gene was not demonstrated in any isolates. bla(OXA 23-like) gene was determined in both Meram and Selcuklu Medical School hospitals, but bla(OXA 58-like) gene was detected only in Meram Medical School hospital. PFGE analysis of the isolates revealed 32 different groups in bla(OXA 23-like) producing A.baumannii strains and 23 different groups determined in bla(OXA 58-like) producing strains. No common epidemic isolates were detected in the two hospitals, however it was noted that some clones produced small outbreaks in Meram MS hospital. In this study it was shown that bla(OXA 23-like) and bla(OXA 58-like) genes together with bla(OXA 51-like) gene had significant roles in the carbapenem-resistance of A.baumannii strains. Carbapenem-resistant A.baumannii strains producing bla(OXA 23-like) and bla(OXA 58-like) enzymes showed the epidemic potential of this nosocomial pathogen and the requirement of molecular typing methods to identify the epidemiologic relationship of the isolates.