فهرست مطالب abdollah kebriaei

 Streptococcus pneumoniae is one of the common bacterial pathogens in pediatrics. In this study, we performed antimicrobial susceptibility testing, serotyping, and molecular typing of blood-isolated strains of pneumococci in Bojnurd.

 In the current study, blood-isolated, penicillin-nonsusceptible S. pneumoniae strains were subjected to antimicrobial susceptibility testing and typing of capsular polysaccharides using the quelling reaction and PCR method, as well as genotyping using the Multi Locus Sequence Typing (MLST) method.

 In this study, 51 S. pneumoniae strains were isolated from blood samples of children less than five-years-old in 2014 - 2018. Antibiogram was performed using the Kirby-Bauer method. All of the isolates were serotyped by the Quelling reaction and PCR. The MLST method was applied to determine the molecular types.

 Our study revealed that the most common serotypes of blood-isolated pneumococci were 19A, 6A/B, 1, 23F, 19F, 14, 15B/C, and 15A, and the common serotypes in Penicillin-nonsusceptible pneumococci (PNSP) isolates were 19F, 19A, 23F, 14, and finally 15A, 6A/B, 1, and 15B/C. The MLST analysis of PNSP isolates revealed that three highly resistant isolates with MIC ≥ 16 belonged to Sweden15A-25-19A (ST63), Taiwan19F-14-1 (ST236), and Taiwan19F-14 (ST236) clones.

 Regarding the common serotypes in this study, it seems that PCV-13 is a suitable choice for vaccination in this area. We also observed a high prevalence of PNSP and multi-drug resistant (MDR) strains between 2014 and 2018. It seems that the Taiwan19F-14 clone and its related STs played an essential role in the diffusion of antibiotic-resistant S. pneumoniae isolates in Bojnurd.

Acinetobacter baumannii is one of the major opportunistic pathogens with increasing clinical significance, particularly in the Hospital setting.
The study aimed to analyze the antibiotic resistance determinants in multidrug-resistant A. baumannii (MDRAB) isolates collected after an outbreak, with regard to the infection prevention control (IPC) interventions to eradicate the outbreak.
Thirty nine isolates of MDRAB were collected during six months of the study after the outbreak. Infection prevention control was successful only for the first three months after the intervention. Antimicrobial susceptibility testing and minimum inhibitory concentrations (MICs) were determined by E-test. In addition, various resistance genes and the clonal relatedness of the isolates were performed by PCR and REP-PCR.
All isolates were MDRAB while being susceptible to colistin. The prevalence of blaADC, blaTEM, blaOXA24, blaVIM, and blaIMP was 82%, 100%, 70%, 61%, and 5%, respectively. blaOXA51, blaOXA23, and ISAba1 were detected in all isolates, but blaOXA58 was not. Moreover, ISAba1 was located upstream to blaOXA23 and blaADC in 100% and 38.4% of the isolates, respectively. The most prevalent AME was aadB (100%). Even though adeB and tetB efflux pumps were found in 100% and 95% of the isolates, respectively, tetA was not characterized. REP-PCR revealed five clusters of which, approximately 51% of the strains belonged to cluster C.
Regarding the molecular approach, the effectiveness of IPC and epidemiological context has been identified. Stringent infection-control measures are urgent to restrict the outbreak.