Background: Uropathogenic Klebsiella pneumoniae is one of the well-kown uropathogens that have the main rule in biofilm formation. Increased prevalence of ESBL enzyme is one of the therapeutic problems. However, the aims of this study were to characterize the ability of biofilm formation and ESBL-producing isolates produced by urinary tract infection’s K. pneumoniae to identify the prevalence of this type of infection in the studied area. Methods: Between the 500 nonrepetitive clinical isolates, 128 isolates were detected as K. pneumoniae . Biofilm production of these isolates was showed by Merrit and Christensen method. The standard Kirby-Bauer disk diffusion method was used for antimicrobial susceptibility testing. The phenotype ESBL was confirmed by double disc synergy test (DDST). Genotypic identification of ESBLs did by molecular detection. The statistical analysis was done using software IBM SPSS Statistics (SPSS Inc) and chi-square and Fisher exact tests. Results: The result of microtiter plate was observed and it was found that 86 (67.2%) isolates had weak biofilm, 24 (18.8%) moderate biofilm, and 18 (14.1%) strong biofilm. Also, 57 (44.5%) out of 128 isolates were diagnosed as MDR. The highest frequency of resistance was identified for cefotaxime 60 (46.9%) and tetracycline 60 (46.9%), and the lowest rate was for amikacin 16 (12.5%). The results of DDST showed 55 of 128 (43%) produced ESBL enzymes. PCR detection in ESBL-producing isolates showed contained bla TEM 33 of 55(63.1%), and bla VEB 13 of 55 (23% ). Also, 1 of 55 (2%) had both bla TEM and bla VEB . Also, 5 of 13 (38.4%) isolates that had the bla VEB gene were also MDR and had weak biofilm (8/13; 61.5%), intermediate biofilm (3/13; 23%), and strong biofilm (2/13; 15.4%). Conclusion: To decrease treatment complications and mortality rate of drug-resistant bacterial infections, rapid detection of β-lactamases genes and evaluation of these properties and infection management programs can help to prevent the transmission of drug resistant-strains.

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10.30699/jambs.28.128.144 Background & Objective: Infections due to burn wounds are serious because of their effects on the course of the disease and its consequences. The rate of burn wound infection is very high in developing countries. The purpose of this study was to identify common bacterial agents causing burn wound infection and determine antimicrobial susceptibility patterns in a burn Hospital, Isfahan, Iran. Materials & Methods: This cross-sectional study was conducted from 2017 to 2018 on all patients with burn wound infection. Burn wounds suspected of infection were collected aseptically and traditional bacteriological methods were used to identify the causes of infection. Antimicrobial resistance test was done by the disk diffusion method in accordance with CLSI recommendations. Results: From the total of 1500 wound culture, 957(63.8%) samples were detected as positive. The highest rate of infection was in the ICU ward and the lowest was in the restoration ward. The most common gram-negative bacteria were Acinetobacter baumannii (34.9%) with the highest and the lowest antibiotic resistance to Ceftazidime and Tobramycin, respectively. Among recovered Gram-positive isolates, Staphylococcus aureus (10.2%) were the predominant isolates with the highest and the lowest antibiotic resistance to Penicillin and Vancomycin, respectively. Conclusion: Due to the variable nature of antibiotic susceptibility patterns and pathogens causing burn wound infection, continuous evaluation, detection of dominant bacterial infections and sensitivity patterns to locally available antibiotics in burn wound patients in order to modify the drug regimen for proper antibiotic treatment is important and seems reasonable.

Backgrounds: Uropathogenic Escherichia coli is a Gram-negative bacillus that is the most common cause of urinary tract infection. E. coli has the ability to produce biofilm as an important virulence factor. Due to the lack of sufficient information about ESBL resistance genes in this geographical area, this study aimed to investigate the prevalence of ESBLs in E. coli isolates to increase our knowledge about the role of these genes and biofilm formation in inducing resistance.Materials & Methods: 139 E. coli strains were isolated from urine samples. Antibiotic susceptibility testing was performed for the isolates by disk diffusion method. ESBL production was confirmed using double-disk synergy test. Molecular detection of ESBL genes was performed using PCR. Biofilm formation assay was performed by microtiter plate method. Findings: The most effective antibiotic against this bacterium was nitrofurantoin. Multidrug resistance was observed in 119 (85.6%) isolates. ESBL phenotype was detected in 93 (66.9%) isolates. The PCR test results showed that bla CTX , bla VEB , and bla TEM were positive in 45 (32.4%), 87 (62.6%), and 10 (7.2%) isolates, respectively. The biofilm formation assay results revealed that 65 (46.8%), 58 (41.7%), 10 (7.2%), and six (4.3%) isolates were non-, weak, moderate, and strong biofilm producers, respectively. Conclusions: The high prevalence of ESBL genes is a public health concern in this region because they could be transmitted to other susceptible bacteria and induce resistance. This study showed that biofilm production could increase antibiotic resistance.

Acinetobacter baumannii is an opportunistic pathogen that is resistant to many antibiotics including beta-lactams. Production of β-lactamases is the main mechanism of β-lactam resistance in A. baumannii strains. The aim of this study was to determine the frequency of bla TEM and bla VEB genes in clinical isolates of A. baumannii and the relationship between the antibiotic resistance and the presence of ESBL genes in strains isolated from burn wound infection in Isfahan. Materials & Methods: In this study, 123 MDR A. baumannii strains were isolated from burn wound infection. After antibiotic resistance evaluation using the Kirby-Bauer disc-diffusion method, all the isolates were evaluated with polymerase chain reaction (PCR) technique to detect ESBL genes, followed by statistical analysis by the end. Findings: Out of 123 A. baumannii isolates, 77 (62.60%) strains were ESBL positive according to the PCR results. The frequency of bla TEM and bla VEB genes was 52 (42.3%) and 67 (54.5%), respectively. There was a significant relationship between the antibiotic resistance and the presence of ESBL genes (bla TEM and bla VEB ) in A. baumannii strains. Conclusion:The high prevalence of bla TEM and bla VEB genes in A. baumannii strains found in this study is the major concern about burn wound infections in Isfahan and Iran because of the complexity in treating infections caused by these strains. This study results highlighted the need for infection control measures to prevent the spread of resistant isolates and ESBL genes, especially in burn hospitals.