Genotypic Diversity of Multidrug Resistant Shigella species from Iran / 감염과화학요법

BACKGROUND: In many developing countries, shigellosis is endemic and also occurs in epidemics and treatment of multidrug-resistant (MDR) isolates are important. The aims of this study were to determine the antimicrobial susceptibility, prevalence of class 1 and 2 integrons and the clonal relatedness of isolates. MATERIALS AND METHODS: Antimicrobial susceptibility tests were performed by disc diffusion method. Polymerase chain reaction (PCR)-sequencing technique was employed for detection and characterization of integrons. The genetic relatedness was evaluated by using enterobacterial repetitive intergenic consensus (ERIC) PCR. RESULTS: There was a high percentage of resistance to trimethoprim-sulfamethoxazole (TMP/SMX) (93.7%), ampicillin (AMP) (87.3%), streptomycin (STR) (84.5%) and tetracycline (TET) (78.9%). Multidrug resistant phenotype was seen in 95.1% of total isolates. Most common MDR profile was TMP/SMX/STR/AMP resistant pattern. Among the 142 Shigella spp. analyzed in this study, 28 isolates were positive for class 1 integron with two types of gene cassette arrays (dfrA17/aadA5 = 31.7% and dfrA7 = 3.8%). The class 2 integron was more frequently detected among the isolates (94.7%) with dfrA1/sat1/aadA1 (69.4%) and dfrA1/sat1 (30.6%) gene cassettes. ERIC-PCR results showed 6, 5, 4 and 3 main genotypes among S. flexneri, S. sonnei, S. boydii and S. dysenteriae isolates, respectively. CONCLUSIONS: Our findings revealed that multidrug resistant Shigella species with high prevalence of class 2 integron were very common in Iran. In addition, ERIC-PCR patterns showed limited variety of clones are responsible for shigellosis in the region of the study.

Genotypic Diversity of Multidrug Resistant Shigella species from Iran / 감염과화학요법

BACKGROUND: In many developing countries, shigellosis is endemic and also occurs in epidemics and treatment of multidrug-resistant (MDR) isolates are important. The aims of this study were to determine the antimicrobial susceptibility, prevalence of class 1 and 2 integrons and the clonal relatedness of isolates. MATERIALS AND METHODS: Antimicrobial susceptibility tests were performed by disc diffusion method. Polymerase chain reaction (PCR)-sequencing technique was employed for detection and characterization of integrons. The genetic relatedness was evaluated by using enterobacterial repetitive intergenic consensus (ERIC) PCR. RESULTS: There was a high percentage of resistance to trimethoprim-sulfamethoxazole (TMP/SMX) (93.7%), ampicillin (AMP) (87.3%), streptomycin (STR) (84.5%) and tetracycline (TET) (78.9%). Multidrug resistant phenotype was seen in 95.1% of total isolates. Most common MDR profile was TMP/SMX/STR/AMP resistant pattern. Among the 142 Shigella spp. analyzed in this study, 28 isolates were positive for class 1 integron with two types of gene cassette arrays (dfrA17/aadA5 = 31.7% and dfrA7 = 3.8%). The class 2 integron was more frequently detected among the isolates (94.7%) with dfrA1/sat1/aadA1 (69.4%) and dfrA1/sat1 (30.6%) gene cassettes. ERIC-PCR results showed 6, 5, 4 and 3 main genotypes among S. flexneri, S. sonnei, S. boydii and S. dysenteriae isolates, respectively. CONCLUSIONS: Our findings revealed that multidrug resistant Shigella species with high prevalence of class 2 integron were very common in Iran. In addition, ERIC-PCR patterns showed limited variety of clones are responsible for shigellosis in the region of the study.

Prevalence of multidrug resistant extended-spectrum beta-lactamase producing gram-negative bacteria in neonatal sepsis

Neonatal sepsis with extended-spectrum beta-lactamase [ESBL] producing microorganisms is recognized increasingly in recent years. ESBL can be produced by various bacterial strains. This study was conducted to determine the prevalence of ESBL producing pathogens in neonatal sepsis and its impact on clinical outcome. A study was carried out from Jan 2012 to Jan 2013 in a referral university hospital. All neonates who had diagnosed as sepsis were enrolled in this study. Blood cultures were processed using the automated BACTEC 9120 system. Antibiotic resistance and beta-lactamase production of bacterial isolates was tested. All patients were followed till discharge. One hundred three neonates with gestation age 36.7 +/- 3.2 weeks were enrolled in this study and 56 cases [54%] were boys. The most common isolated gram negative pathogens were Klebsiella pneumoniae, Acinetobacter species, and Pseudomonas aeruginosa. The rate for beta-lactamase production were 97.7% in Klebsiella pneumoniae, 81.3% in Acinetobacter, 85.7% in E. coli, 53.3% in Pseudomonas aeruginosa and 100% in Serratia. Thirty eight [35.9%] neonates were dead, that 34 of them were beta-lactamase producers. The mean duration of hospitalization were longer in patients infected with beta-lactamase producers [30.2 +/- 20.5 vs. 22.8 +/- 16.6 days P=0.05] and ESBL producing strains [29.13 +/- 20.39 vs. 19 +/- 9.84 P=0.05]. ESBL production rate were determined 95.5% and 86.7% in Klebsiella pneumoniae by combined disk test [CDT] and double disk synergy test [DDST] method, respectively. These methods were positive for ESBL production in 78.6% and 64.3% of E. coli isolates, respectively. In our study, the high rate of beta-lactamase and ESBL production were determined for common isolated organisms in neonatal sepsis. Infection with ESBL producing pathogens was associated with longer hospital stay. CDT method was detected more ESBL producing pathogens than DDST method in our study. It is recommended future studies to determine the risk factors predisposing newborn infants with these pathogens

Detection of acute childhood meningitis by PCR, culture and agglutination tests in Tabriz, Iran

Meningitis is one of the hazardous and life threatening infections and is associated with mortality and morbidity. The aim of this study was to determine etiological agents of childhood bacterial meningitis. The culture, Gram staining, agglutination and PCR assays were used to examine CSF specimens from 277 patients with presumed bacterial meningitis for the occurrence of 4 most common infectious agents consist of N. meningitis, H. influnsae, S. pneumoniae and S. agalactiae between 2008 and 2009 at different wards of the Children Hospital of Tabriz. The mean age of patients was 35 +/- 2 [Mean +/- SEM] month, [minimum 11 days maximum14 years], of all cases 59.6% male and 40.4% female. Overall the diagnosis was confirmed with a CSF culture in 11/277 [3.97%], by agglutination test in 14/277 [5.05%]. The isolated bacteria included S. pneumoniae 5 cases, H. influnsae 2 cases, N. meningitis 3 cases and P. aeroginusae 1 case. A positive PCR assay allowed us to diagnose bacterial meningitis in 19 patients [6.8%]. In the present study, we found PCR to be a useful and sensitive method for the detection of bacterial DNA in the CSF samples from suspected meningitis patients. Furthermore, to maximize management of meningitis cases, a combination of culture and PCR is necessary