Predominance of t355/ST152/SCCmec V clonal type among PVL-positive MRSA isolates in a tertiary care hospital in Belgrade, Serbia

Epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) is continually changing. Frequency of genotypes typical for community-associated MRSA (CA-MRSA) is increasing in hospitals, as well as resistance to antimicrobial agents. Moreover, different clones predominate in different geographic regions, and temporal shifts occur in the predominant clonal type. The aim of this study was to estimate the prevalence of MRSA, CA-MRSA and PVL-positive MRSA isolates from patients hospitalised in the Military Medical Academy (MMA) and from outpatients, and to perform genotyping of PVL-positive MRSA isolates. MRSA isolates were obtained by standard microbiological techniques. PVL-positive MRSA were detected by single PCR. Determination of SCCmec types in MRSA isolates was done using multiplex PCR and genotyping of PVL-positive MRSA by PFGE, MLST and spa typing. The prevalence of MRSA among S. aureus isolates from different clinical specimens was 43.4%. In outpatients the prevalence of MRSA was 3.2%. SCCmec types specific for CA-MRSA were found in 26% of MRSA isolates from hospitalised patients. In groups, hospitalised patients and outpatients, the prevalence of PVL-positive MRSA isolates was 4%, and all of them harboured SCCmec type V genetic element. PFGE revealed minor differences between four groups of PVL-positive MRSA isolates, but all of them belonged to ST152, and all except one were of the t355 spa type. High prevalence of MRSA and CA-MRSA in MMA, especially the presence of PVL-positive CA-MRSA, represent a serious health threat for patients. Genotype t355/ST152/SCCmec V is the dominant MRSA clone among PVL-positive CA-MRSA.

Typing of Indigenous Campylobacter spp. From Serbia by M-PCR and RAPD

Campylobacteriosis is an infectious human disease caused by thermophilic Campylobacter species, mainly C. jejuni and C. coli. It is the leading cause of human gastroenteritis today with the number of cases surpassing the number of Salmonella poisoning cases. The epidemiology of the agent is not completely clear, but a number of investigations indicate an important role of broiler meat in human infections. The purpose of this study was to investigate the diversity of Campylobacter jejuni strains present in the Republic of Serbia and to determine a fast and reliable system for the confirmation and typing of the isolated strains. Samples taken at slaughterhouses, broiler farms, as well as two human isolates of Campylobacter species have been investigated. Strain identification was performed by multiplex-PCR. Genotyping was performed by Random Amplified Polymorphic DNA (RAPD) with multiple primers. Using several unusual primers and a newly designed one (DJP17), we report on the RAPD types of indigenous Campylobacter species. RAPD profiles showed different levels of discrimination between the isolates, depending on the primer: SPH1 and AG15 were informative only in part and better results were obtained with AP10, AK16 and DJP17.

Shiga toxin-producing Escherichia coli O171:H25 strain isolated from a patient with haemolytic uraemic syndrome

Shiga toxin-producing Escherichia coli (STEC) strains of O157:H7 serotype are a predominant cause of haemolytic uraemic syndrome (HUS) worldwide, but strains of non-O157 serotypes can also be associated with serious disease. Some of them are associated with outbreaks of HUS, others with sporadic cases of HUS, and some with diarrhoea but not with outbreaks or HUS. A large number of STEC serotypes isolated from ruminants and foods have never been associated with human disease. In this study we characterize a STEC strain belonging to serotype O171:H25 that is responsible for a case of HUS. This strain has a single Shiga toxin gene encoding Stx2 toxin, and hlyA gene, but is eae-negative.