mohadeseh zarei

Antibiotic resistance in Pseudomonas aeruginosa is an increasing health problem. Integrons are associated with a variety of gene cassettes, which confer resistance to multiple classes of antibiotics. This study aimed at screening the presence of class 1, 2 and 3 integrons in P. aeruginosa in Yazd, Iran. This study was carried out on P. aeruginosa strains from March 2016 to March 2017. Clinical specimens were initially identified by the standard biochemical methods and their resistance patterns to antibiotics were studied using the disc diffusion method. PCR was carried out for the detection of class 1, 2 and 3 integrons using intI1, intI2 and intI3 gene primers, respectively. Antimicrobial susceptibility test showed that 75% of isolates were detected as multi-drug resistant (MDR), and lowest resistance was observed in ciprofloxacin (48.6%) and most resistance was in gentamicin (63.2%). Moreover, PCR results showed that 22 (15.3%) and 119 (82.6%) of P. aeruginosa isolates carried intI2 and intI1 genes, but intI3 gene was not found. Since it is customary to observe Class I integrons in P. aeruginosa isolated from clinical samples, they are often responsible for antibiotic resistance gene transfer, which calls for evaluation of integrons as contributing factors in antibiotic resistance

Pseudomonas aeruginosa is one of the most important causative agents among the hospital acquired infections, especially in ICU and burn units. Enzymatic inactivation of aminoglycosides by aminoglycoside-modifying enzymes is the main mechanism of resistance to these antibiotics in Pseudomonas aeruginosa. The aim of this study was to study the aminoglycoside resistance and ant (2”)-I in Pseudomonas aeruginosa isolated from burn specimens in Yazd, Iran.
This cross-sectional study was carried out on Pseudomonas aeruginosa isolates (no=73) during July 2014 to April 2015. All burn wound samples were initially identified by the standard biochemical methods and their aminoglycoside resistance was studied using the disc diffusion method according to CLSI recommendations. PCR method was carried out for the detection of aminoglycoside resistance using ant (2”)-I gene specific primers.
Forty (54.8%) out of 73 cases were male (mean age 29±2.25 years). The resistance rates as determined by the disk diffusion method were: Kanamycin (89%), Gentamicin (67.1%), Tobramycin (58.9%) and Amikacin (60.3%). The PCR results showed that 63 (86.3%) of the isolates were harbored the ant (2”)-I gene.
The results of this study show that resistance to aminoglycosides is high in pseudomonas aeruginosa isolated from burn wounds. The presence of gene ant (2”)-I was widely reported. In addition, there was a significant relationship between this gene and resistance to aminoglycosides.

Pseudomonas aeruginosa is a gram-negative, non-fermentative bacillus and one of the most common opportunistic human pathogen causing 10-15% of nosocomial and burn wound infections worldwide. These bacteria are resistant to most of the antibiotics. This study aimed to investigate the frequency of extended spectrum β-lactamase (ESBL) and metallo-β-lactamase (MBL) enzymes in P.aeruginosa strains isolated from burn wounds. In this descriptive cross-sectional study, 180 wound specimens were collected from patients hospitalized in burn hospital and then cultured. The suspected colonies were identified using the conventional biochemical methods. Susceptibility testing was performed using the Kirby-Bauer method. Moreover, the Combination Disk and E.test methods were used for the determination of ESBLs and MBL, respectively. Fifty-four (30%) out of 180 cultured samples were identified as p.aeruginosa; 12 (22%) and 16 (29.5%) isolates were ESBLs and MBL producer, respectively. Overall, 42 (79%), 40 (74%), 40 (74%), 38 (70%), 35 (66%) and 34 (62%) isolates were resistant to ceftizoxime, imipenem, gentamycin, piperacillin, cefepime, meropenem and ertapenem, respectively. Results reveal that the antimicrobial resistance and prevalence of ESBLs and MBL producing P.aeruginosa strains is increasing in our hospital and it is necessary to perform susceptibility testing, control risk factors and reasonably prescribe the appropriate antibiotics. Considering the diversity of ESBL and MBL classes and their prevalence in different areas, performing molecular research is needed.

Antimicrobial resistance in Pseudomonas aeruginosa has been increasing in recent years. The aim of this study was to investigate the relationship between antimicrobial resistance and class I integron in P. aeruginosa isolated from clinical specimens in Yazd city. This cross-sectional study was carried out on 144 P. aeruginosa strains from April 2012 to April 2013. All clinical samples were initially identified by the biochemical method and the antibiotic resistance test was performed using the disc diffusion method according to CLSI recommendations. PCR was carried out for the detection of class I integron. Seventy-nine (54.9%) out of 144 patients were male with mean age of 34.9+22.7 years. Resistance rates to various antibiotics were as follows: gentamicin (63.2%), imipenem (62.5%), amikacin (58.3%), ceftazidime (56.9%), ticarcillin (55.6%), tobramycin (55.6%), piperacillin (54.9%) and ciprofloxacin (48.6%) and 75.3% of the isolates were detected as multi-drug resistant. PCR results showed that 119 (82.6%) P. aeruginosa isolates carried class I integron. Class I integrons are commonly found in P. aeruginosa isolated from the clinical samples. Therefore, the transfer of antibiotic resistance genes is often related to these integrons and the contribution of integrons in antibiotic resistance should be evaluated.

Pseudomonas aeruginosa is a Gram-negative bacterium that plays a major role in development of opportunistic and severe infections in burn patients. Occurrence of enzymes capable of inactivating all beta-lactams including carbapenems is new problem in treatment of patients. The objective of this study was to investigate the prevalence of Metallo-Beta-Lactamases (MBL) enzymes blaVIM, blaIPM and blaNDM in Pseudomonas aeruginosa strains isolated from burn wounds in Yazd city, Iran. In this cross-sectional study, 180 burn wound-specimens were collected from burn-hospital belonged to Shahid Sadoughi University of Medical Sciences in Yazd during one year and were cultured at microbiology laboratory of School of Medicine of this university. Suspected colonies were identified by conventional biochemical methods such as utilization of sugars, motility, and oxidase production. Sugar utilization in the Oxidation-Fermentation medium (OF), growth at 42°C and pigment production tests were performed for oxidase positive and non-fermentative colonies on Triple Sugar Iron (TSI) test. Antibiotic susceptibility was determined by Kirby-Bauer methods according to the Clinical and Laboratory Standards Institute (CLSI) standards. Etest metallo-beta-lactamase (Etest MBL) method was used for phenotypic detection of MBL and blaVIM, blaIPM and blaNDM were determined by polymerase chain reaction (PCR) method using specific primers. Out of 180 burn wound specimens, 54 (30%) was identified as Pseudomonas aeroginosa. Out of 54 isolates, 70%, 66% and 74% were resistance to ertapenem, meropenem and imipenem respectively; 64% and 74% of isolates were resistant to meropenem and imipenem respectively. MBL enzymes were detected in 29.5% of isolates. Nine isolates (16.6%) and 5 isolates (9.2%) had blaVIM and blaIPM respectively and 2(3.7%) isolates had blaVIM and blaIPM simultaneously. None of the isolates had blaNDM. The results of this study show that the prevalence of MBL enzymes and antibiotic resistance in burn patients is high and it is necessary to determine susceptibility testing before treatment.