Occurrence of class 2 integrons among multi-drug resistant Shigella sonnei isolated from Tehran, Iran in 2005

Shigellosis is one of the major causes of morbidity in children with diarrhea in Iran. Integrons play an important role in the evolution and dissemination of multidrug resistance in gram-negative bacteria. The occurrence of integrons among Shigella spp. is frequently reported throughout the world. The aim of this study was to assess the occurrence of class 2 integrons among the multi drug resistant S. sonnei isolated from Iranian children in 2005. The study was conducted in two major pediatric hospitals in Tehran, Iran. Fecal specimens and rectal swab collected from patients were cultured and identified as Shigella by the conventional methods. Antimicrobial susceptibility test was performed according to the standard CLSI guideline. Multi-drug resistant isolates of S. sonnei were further examined for the presence of class 2 integron by PCR using specific primers. Amplicons were confirmed by restriction endonuclease analysis. A total of 83 multi-drug resistant S. sonnei strains were isolated. Of these, 45 [54%] exhibited a class 2 integron of 2.1 kbp, and 34 [41%] a class 2 integron of 1.3 kbp. Class 2 integrons were not detected in four isolates. The results showed an increased occurrence of class 2 integron carrying S. sonnei isolated from children in Tehran in 2005

MRSA ST22-IVa [EMRSA-15 clone] in Palermo, Italy

Epidemic spread of methicillin-resistant Staphylococcus aureus [MRSA] strains carrying the Staphylococcal Chromosomal Cassettes [SCC] mec type IV is being increasingly reported in many geographical areas. A survey to determine the prevalence and characteristics of MRSA SCCmec IV isolates identified in four general hospitals in Palermo, Italy, was carried out. During the period February-June 2009, SCCmec type IVa has been found in12 out of 94 isolates. Nine isolates from all hospitals and all strains from a NICU outbreak occurring in the same period were attributed with the ST22-IVa [EMRSA-15] clone. In our setting, due to the changing MRSA epidemiology, detection of SCCmec IV could be poorly predictive of CA-MRSA

combined molecular typing approach does not discriminate Legionella pneumophila serogroup 1 strains of a predominant sequence-based type in Palermo, Italy

The sequence-based type 1,4,3,1,1,1 of Legionella pneumophila sg.1 is predominant in the Palermo city environment since several years. In this study, extended sequence-based typing and pulsed field gel electrophoresis were used in a combined approach in the aim to enhance discriminatory power of the molecular typing procedures. However, probably due to a common environmental reservoir and genetic stability, most of the strains circulating in the geographic area under study belong to the same clone and are, consequently, indistinguishable by molecular typing. Investigations of clinical cases and tracing to their environmental source require caution and support from sound epidemiological data