Correlation of ciprofloxacin resistance with the AdeABC efflux system in Acinetobacter baumannii clinical isolates

Background: Acinetobacter baumannii is one of the most important pathogens capable of colonization in burn patients, leading to drug-resistant wound infections. This study evaluated the distribution of the AdeABC efflux system genes and their relationship to ciprofloxacin resistance in A. baumannii isolates collected from burn patients. Methods: A total of 68 A. baumannii clinical strains were isolated from patients hospitalized in Motahari Burns Center in Tehran, Iran. Ciprofloxacin susceptibility was tested by the disk diffusion and agar dilution methods. PCR amplification of the adeRS-adeB drug efflux genes was performed for all resistant and susceptible isolates. To assess the role of the drug efflux pump in ciprofloxacin susceptibility, carbonyl cyanide 3-chlorophenylhydrazone (CCCP) was used as an efflux pump inhibitor (EPI). Results: Approximately 95.6% of the Acinetobacter isolates were resistant to ciprofloxacin, with minimum inhibitory concentration (MIC) values ranging from 4 to ≥128 μg/mL. The susceptibility of 86.1% of the resistant isolates increased by factors of 2 to 64 in the presence of CCCP. All resistant isolates were positive for the adeRS-adeB genes, and 73.2% of them had mutations in the AdeRS regulatory system. Conclusions: The results showed that AdeABC genes are common in A. baumannii, which might be associated with ciprofloxacin non-susceptibility, as indicated by the observed linkage to the presence of the genes essential for the activity of the AdeABC, several single mutations occurring in the adeRS regulatory system, and an increase of ciprofloxacin susceptibility in the presence of a CCCP EPI. © The Korean Society for Laboratory Medicin

Comparison of efflux pump involvement in antibiotic resistance among pseudomonas aeruginosa isolates of burn and non-burn patients

Background: Pseudomonas aeruginosa is an important cause of hospital-acquired infections that can create serious problem for patients and physicians. Many factors are associated with the antibiotic resistance of P. aeruginosa, such as efflux pumps. Objectives: The aim of this study was the phenotypic and molecular detection of efflux pumps in our clinical P. aeruginosa isolates in a comparison between burn and non-burn specimens. Materials and Methods: In this study, clinical strains of P. aeruginosa were collected from burn and non-burn specimens from April-July 2013. Antibiotic susceptibility testing of the isolates was performed after biochemical and molecular identification. The minimum inhibitory concentration (MIC) of imipenem, cefepime, gentamycin, and ciprofloxacin, with and without carbonyl cyanide 3-chlorophenylhydrazone (CCCP), was determined for phenotypic detection of efflux pumps. Results: Our results confirmed 203 and 60 P. aeruginosa isolates from burn and non-burn specimens, respectively. The most antibiotic resistance was observed against tobramycin in both group of specimens, and no resistance was seen to colistin. Phenotypic detection of efflux pumps was determined to correlate to a > 4-fold decrease in the MICs of the tested antibiotics with CCCP compared to without CCCP in 57 strains. Conclusions: High-level antibiotic resistance can occur as a result of multidrug efflux pumps combined with other mechanisms of resistance. However, the association between over-expression of these genes and highly resistant clinical isolates cannot be ignored. � 2016, Pediartric Infections Research Center

The pattern determination of sea surface temperature distribution and chlorophyll a in the southern Caspian Sea using SOM model

Remote sensing has changed modern oceanography by proving synoptic periodic data which can be processed. Since the satellite data are usually too much and nonlinear, in most cases, it is difficult to distinguish the patterns from these images. In fact, SOM (Self-Organizing Maps) model is a type of ANN (Artificial Neural Network) that has the ability to distinguish the efficient patterns from the vast complex of satellite data. In this study, the sea surface temperature data and chlorophyll a related to a part of south Caspian Sea were investigated weekly by NOAA satellite for three years (2003–2005) and the annual and seasonal patterns were extracted (elicited) with their relative frequency using the SOM model. In all patterns the Caspian Sea coast has the highest chl-a and when you go away from the shore the rate decreases and when you approach to the middle parts the chl-a is of the least proportion on the sea surface

Detection of the efflux-mediated erythromycin resistance transposon in streptococcus pneumoniae

Background: The present analysis focuses on phenotypic and genotypic characterizations of efflux-mediated erythromycin resistance in Streptococcus pneumoniae due to an increase in macrolide resistance in S. pneumoniae worldwide. Methods: We investigated the prevalence of efflux-mediated erythromycin resistance and its relevant genetic elements from 186 specimens of S. pneumonia isolated from clinical and normal flora from Tehran, Iran. The presence of erythromycin resistance genes was tested by PCR with two sets of primers, specific for erm(B) and mef(A/E), and their genetic elements with tetM, xis, and int genes. Isolates were typed with the BOX PCR method and tested for resistance to six antibiotics. Results: Antibiotic susceptibility tests revealed that 100 and 47 isolates were resistant to tetracycline and erythromycin, respectively. The erythromycin and clindamycin double-disc diffusion test for macrolide-lincosamide-streptograminB (MLSB) resistance phenotype showed 74 (84) isolates with the constitutive MLSB phenotype and the remaining with the M phenotype. BOX PCR demonstrated the presence of 7 types in pneumococci with the M phenotype. Fourteen (16) isolates with the M phenotype harbored mef(A/E), tetM, xis, and int genes. Conclusion: The present results suggest dissemination of polyclonal groups of S. pneumoniae with the M phenotype carrying resistance genes attributed to transposon 2009. © The Korean Society for Laboratory Medicine

Psychosocial determinants of dental service utilization among adults: Results from a population-based survey (Urban HEART-2) in Tehran, Iran

Objectives: To evaluate the association between dental service utilization and mental health in an adult population in the context of the socioeconomic status of the participants. Subjects and Methods: Multi-stage cluster random sampling was performed in Tehran, Iran, in 2011. Data were collected on dental service utilization, barriers of dental visit, self-perceived oral health, mental health, age, gender, education, and wealth status. The complex sample analysis method in SPSS and the survey data analysis menu in STATA were employed for statistical evaluation. Results: Of 20,320 participants, 25-36 suffered from disorders in at least one of the domains of somatization, anxiety, social dysfunction, and depression. Only 56 of the participants visited a dentist at least once during the last year. The main barriers to a dental visit were "no perceived need" and "high costs." Females, the richest participants, subjects aged 25-64-year-old, and those with poor self-perceived oral health, mental health disorders, and higher education had more visits. The participants who perceived the need but did not visit a dentist due to some reasons mostly comprised females, those aged 25-44-year-old, those with a poor perceived oral health, disordered people in all domains of mental health, and poorer participants. Conclusion: Dental service utilization was influenced by socioeconomic factors and the mental health status of the adult population after controlling for multiple confounders. Reducing financial hardship and providing health education on the importance of preventive visits may decrease barriers to regular visits in countries with developing oral health systems. © 2015 European Journal of Dentistry

Phenotypic and molecular characterization of plasmid mediated AmpC among clinical isolates of Klebsiella pneumoniae isolated from different hospitals in Tehran

Introduction: Klebsiella pneumoniae is one of the main opportunistic pathogens which can cause different types of infections. Production of beta-lactamases like AmpC and ESBL mostly lead to beta-lactam resistance in these Gram-Negative bacteria. The aim of this study was the detection of AmpC-producing K. pneumoniae in clinical isolates. Materials and Methods: Three hundred and three isolates of K. pneumoniae were identified. Double disc method including cefoxitin with cefepime and using boronic acid with cloxacillin were performed as two phenotypic methods for detection of AmpC. Amplification of AmpC gene was performed by PCR. Results: Eight and three isolates showed positive results in double disc method and by using boronic acid with cloxacillin, respectively. Five isolates had specific band for AmpC gene after electrophoresis. Conclusion: Our results were indicated the low prevalence of AmpC-producer-K. pnemoniae in Iran. On the other hand these two tested phenotypic methods showed low sensitivity for detection of AmpC. © 2015 Journal of Clinical and Diagnostic Research. All Rights Reserved

Prevalence of high-level gentamicin-resistant Enterococcus faecalis and Enterococcus faecium in an Iranian hospital

This study was designed to determine the molecular characteristics and antimicrobial resistance of enterococcal strains isolated from patients admitted to an Iranian Hospital. Enterococcal strains were isolated from the burn patients. All strains were screened for genes encoding resistance to aminoglycoside aac(6')-Ie-aph(2'')-Ia, aph (3'), ant (4'), resistance to vancomycin (vanA, vanB), resistance to tetracycline (tetK, tetL, tetM, tetO), and resistance to erythromycin (ermA, ermB, ermC) by PCR and multiplex PCR-based methods. Genetic diversity was evaluated via Random Amplified Polymorphic DNA (RAPD)-PCR. All enterococcal isolates showed complete sensitivity to vancomycin with MIC � 0.5μg/ml. Resistance to gentamicin, tetracycline, erythromycin, ciprofloxacin or quinopristin-dalfopristin was detected, whilst more than 96.2% of isolates were high-level gentamicinresistant (HLGR) and multiple drug resistant. The most prevalent aminoglycoside resistance gene was aac(6')-Ie-aph(2'')-Ia, that was found in 96.2% (26/27) of the isolates. The most prevalent tetracycline resistance genes were tetM, found in 85.1% (23/27) followed by tetL and tetO found in 7.4% (2/27) of the isolates. The ermA and ermB genes were detected in 33.3% (9/27) and 44.4% (12/27) of the isolates respectively. RAPD-PCR analysis yielded 17 distinct profiles among 27 investigated isolates. One cluster of isolates shared the same RAPD pattern, while 16 isolates had unique RAPD pattern. Our study showed that during the examination time period one RAPD genotype was the common type and was disseminated among patients in the burn unit. Interestingly, most of these strains had an identical or very similar antibiotic and gene resistance pattern

Evaluation of various staphylococcal cassette chromosome mec (SCCmec) types in staphylococcus epidermidis invasive strains from hospitalized patients in Iran Valutazione di tipi diversi di cassetta cromosomica stafilococcica mec (SCCmec) in ceppi invasivi di Staphylococcus epidermidis isolate da pazienti ospedalizzati in Iran

Staphylococcus epidermidis is known to be a major cause of nosocomial infections particularly in catheter-associated bacteraemia, prosthetic valve endocarditis (PVE) and immunocompromised patients in different health care units. The emergence of multidrug-resistant strains, especially to β-lactam antibiotics such as methicillin, has increased the mortality due to S. epidermidis. A kind of low affinity penicillin-binding protein (PBP2α), which is encoded by the mecA gene that is located in the staphylococcal cassette chromosome mec (SCCmec), mediates the resistance to methicillin. The aim of this study was to investigate the prevalence of SCCmec types and evaluate the antibiotic profile assay in invasive strains isolated from clinical samples. The study focused on invasive strains, determining the antimicrobial resistance profile, designing new primers for detection of the mecA gene and SCCmec typing with the multiplex PCR method. By using the PCR molecular test, 87.1 of all isolates were found to be positive for the mecA gene. In SCCmec typing, different types (I-V) were identified, in which SCCmec type I was detected in 3 isolates, SCCmec type II in 5 isolates, SCCmec type III in 22 isolates, SCCmec type IV in 27 isolates and SCCmec type V was distinguished in 4 isolates. Since coagulase- negative staphylococci are reported as a major cause of hospital infections, molecular typing methods like SCCmec typing would be a helpful method to control and prevent bacterial infections. © 2015, EDIMES Edizioni Medico Scientifiche. All rights reserved

Characteristics of dermatophytoses among children in an area south of Tehran, Iran

The aim of this study was to determine the prevalence and etiological agents of dermatophytoses, and also their distribution according to age, gender, and body site among children in an area south of Tehran. A total of 382 children aged �16 years suspected to have dermatophytic lesions were examined over a period of 3 years (1999-2001). The incidence rate of dermatophytoses was 6.6 per 100 000 person-years. Trichophyton violaceum was the most frequent isolate (28.3) followed by Microsporum canis (15.1), Epidermophyton floccosum (15.1), T. rubrum (13.2), T. mentagrophytes (11.3), M. gypseum (7.5), and T. verrucosum (5.7). Tinea capitis (39.6) was the most common type of infection, followed by tinea corporis (30.2), tinea faciei (18.9), and tinea manuum (7.5)