High incidence of type III secretion system associated virulence factors (exoenzymes) in Pseudomonas aeruginosa isolated from Iranian burn patients.

OBJECTIVE: The present study aimed to determine the prevalence of virulence factors and antimicrobial resistance profile of Pseudomonas aeruginosa strains isolated from Iranian burn patients. RESULTS: This cross-sectional study performed on 100 P. aeruginosa isolates which were recovered from burn wound specimens in 2014-2015. All presumptive isolates were identified by standard microbiologic tests. Antimicrobial susceptibility test was carried out by disk diffusion method. The presence of virulence genes was determined by PCR method. Antibiotic susceptibility results revealed that the isolates were mostly susceptible to amikacin (61%), ceftazidime (60%), and imipenem (55%). Moreover, 59% of the isolates were multi-drug resistance (MDR). The most prevalent MDR pattern was aminoglycosides-penicillins-fluoroquinolones-carbapenems (15%). The presence of exoT, exoY, exoS and exoU genes was detected in 100%, 100%, 59%, and 41% of the tested isolates, respectively. Results points out the pattern of MDR and genetic diversity of type III secretion system among P. aeruginosa strains isolated from the burn population. Overall, the association of MDR and the presence of the specific virulence genes can be a predictive marker for the persistence of these isolates in the hospitals and subsequently a worse clinical condition for the affected patients.

Seroepidemiology of leptospirosis in Guilan province, northern Iran: comparison between MAT and IgM-ELISA techniques.

INTRODUCTION: Leptospirosis is a widespread zoonotic disease which is endemic in Guilan province, Iran. Besides economic losses in the dairy industry, leptospirosis is also considered an important public health problem. This study aimed to evaluate two serological techniques, MAT and IgM-ELISA for detection of leptospiral antibodies. METHODOLOGY: A total of 185 samples were collected from individuals in Guilan province suspected of having leptospirosis from April 2016 to December 2016. Sera from participants were analyzed for Leptospira IgM antibodies using an available ELISA test and the MAT method. The specificity and sensitivity of the tests were calculated and compared. RESULTS: Of the 185 serum samples examined 114 (61.6%) and 94 (50.8%) samples were determined to be positive by MAT and IgM-ELISA, respectively. The results also showed that 17.5% of the sera that reacted positive in MAT were negative by IgM-ELISA, and 20.2% of IgM-ELISA positive sera were negative by MAT. We also showed that the MAT had specificity and sensitivity of 100%, when compared to leptospirosis-positive and negative serum samples. The specificity and sensitivity of IgM-ELISA was calculated as 78.8% and 82.4% respectively when compared with MAT. Bivariate analysis showed high correlation between the season, community of residence, possible reasons of pollution and leptospirosis (P < 0.1). CONCLUSION: Rural areas of Guilan, especially rice farming areas, are endemic for leptospirosis. Rice farmers have a high risk of infection with leptospirosis; infection is associated with direct exposure to rodent urine, gender (male) and season (spring).

Antibiotic Resistance Pattern and Distribution of pslA Gene Among Biofilm Producing Pseudomonas aeruginosa Isolated From Waste Water of a Burn Center.

BACKGROUND: Pseudomonas aeruginosa is considered as a major cause of hospital-acquired infections due to its high antibacterial resistance. Biofilm formation is a well-known pathogenic mechanism in P. aeruginosa infections, since sessile bacteria are protected in an extracellular matrix of exopolysaccharide. The expression of polysaccharide synthesis locus (pslA gene) can be important for biofilm formation by P. aeruginosa. OBJECTIVES: The purpose of this research was to evaluate the antibiotic resistance pattern and distribution of the pslA gene among biofilm-producing P. aeruginosa isolates obtained from waste water of Burn Centre in Guilan, Iran. MATERIALS AND METHODS: Fifty isolates of P. aeruginosa were obtained from waste water of a burn center. The P. aeruginosa isolates were identified using standard bacteriological procedures. Drug susceptibility test was performed by disk diffusion method for all the isolates against nine antimicrobial agents. Biofilm formation was measured by microtiter plate assay. Polymerase chain reaction (PCR) was used to identify the presence of the pslA gene among the isolates. RESULTS: Biofilm formation was observed in 70% of the P. aeruginosa isolates. The potential formation of biofilm was significantly associated with resistance to gentamicin, imipenem, tobramycin and piperacillin. In addition, the pslA gene only existed in biofilm-producing isolates with a frequency of 42.9% (n = 15). CONCLUSIONS: The findings of the present study well demonstrated that the P. aeruginosa biofilm-producing isolates were more resistant to the tested antibiotics. Furthermore, because of wide distribution, it seems that the pslA gene is associated with biofilm formation.

Antibiotic resistance and frequency of class 1 integrons among Pseudomonas aeruginosa, isolated from burn patients in Guilan, Iran.

BACKGROUND AND OBJECTIVES: Antibiotic resistance of Pseudomonas aeruginosa remains a major problem in burn patients. The main objective of this study was to determine the antibiotic resistance pattern and frequency of class 1 integrons among P. aeruginosa strains isolated from patients with burn wound infections in a new Burn Centre in Guilan, Iran. MATERIALS AND METHODS: The bacterial isolates were collected from 182 patients with burn wound infections and P. aeruginosa species were identified by standard bacteriological methods. The drug susceptibility test, using 11 antimicrobial agents, was performed for all the isolates via agar disk diffusion method. PCR was carried out for the detection of integrons. RESULTS: Out of a total of 182 hospitalized patients in the burn center assessed, 86 (47%) found to have P. aeruginosa in their isolates. Resistance rates to various antibiotics were as follows: cloxacillin (91.8%), cotrimoxazole (86%), cephazolin (83.7%), carbenicillin (74.4%), piperacillin (69.9%), ceftazidime (68.8%), ciprofloxacin (66.3%), tobramycin (58.2%), amikacin (48.8%) and gentamicin (37.2%), while the most effective antibiotic was imipenem with a resistance rate of 23.3%. Thirty nine (45.3%) isolates were detected as multi-drug resistant. The PCR results showed that 37 (43%) P. aeruginosa isolates and 27 (69.2%) multi-drug resistant strains harbored class 1 integrons. A significant correlation was obtained between the presence of integrons and resistance against imipenem, ceftazidime, piperacillin and ciprofloxacin (P <0.001). CONCLUSION: Optimization of using antimicrobial agents and control of infection is recommended to prevent the increasing population of drug resistant organisms in the new burn centre setting in this study. Furthermore, the high frequency of class 1 integrons among multi-drug resistant strains might be responsible for dissemination of antibiotic resistance gene.