Salmonellosis is an important disease both in animals and human which is caused by different serovars of Salmonella enterica. Serovars Enteritidis is one of the most prevalent serovars among animals and poultry and also is the food-borne pathogen. The aim of this study was to identify the prevalence of blaVEB, blaPER, and blaGES in Salmonella Enteritidis isolated from poultry meat samples. In this study, 60 Salmonella samples isolated from chickens were collected and confirmed as Salmonella by culture and biochemical tests. Serotyping was performed using O and H antisera. Multiplex-PCR was conducted for the identification of ESBL genes including blaPER, blaVEB, and blaGES. The serotyping results showed that all of the 60 samples belonged to group D and serovars Enteritidis. Among 60 samples, 3 had the blaPER, 2 had the blaVEB and 1 harbored the blaGES gene. Antibiogram results showed the most resistance was to ceftazidime (64%) and the most susceptibility was to meropenem and ceftizoxime (92%). Since Salmonella is a food-borne bacterium, the presence of ESBL in food samples even in small numbers can be a serious alarm.

Background: The aim of this study was to determine the frequency of blaNDM, blaPER, bla VEB, blaIMP and bla- VIM type genes among A. baumannii isolates from hospitalized patients in Milad and Loghman Hakim hospitals, Tehran- Iran from 2012 to 2013.Methods: This study was conducted on 108 A. baumannii isolates collected from Milad and Loghman Hakim hospitals in Tehran, Iran. Antibiotic susceptibility tests were performed by Kirby-Bauer disc diffusion and Broth micro dilution methods according to CLSI guidelines. The frequency of MBL (metallo-beta-lactamase) and ESBL (extended spectrum- beta-lactamase) producers were evaluated by CDDT (Combined disk diffusion test). The blaNDM, bla- PER, blaVEB, blaIMP and blaVIM genes were detected by PCR and sequencing methods.Results: The resistance of A. baumannii isolates to the tested antibiotics were as follow: 103 (95.4%) to ceftazidime, 108 (100%) to cefotaxime, 105 (95.7%) to cefepime, 99 (91.7%) to imipenem, 99 (91.7%) to meropenem, 87 (80.6%) to amikacin, 105 (97.2%) to piperacillin, 100 (92.6%) to ciprofloxacin, 103 (95.4%) to piperacillin/tazobactam, 44 (40.7%) to gentamicin, 106 (98.1%) to ampicillin/sulbactam, 106 (98.1%) to co-trimoxazole, 87 (80.6%) to tetracycline and 1 (1.8%) to colistin. Using combined disk diffusion test, it was found that out of 108 cefotaxime-non-susceptible A. baumannii strains, 91 (84.2%) were ESBL producers and out of 99 imipenem non-susceptible A. baumannii strains, 86 (86.86%) were MBL producers. The prevalence of blaPER-1 and blaVEB-1 genes among 91 of ESBL-producing A. baumannii isolates were 71 (78.03%) and 36 (39.5%), respectively. The prevalence of IMP-1 and VIM-1 genes among metallobeta- lactamase-producing A. baumannii isolates was 3 of 86 (3.48%) and 15 of 86 (17.44%) respectively and also confirmed for blaOXA-51 gene by PCR. Fortunately, blaNDM gene was not detected in isolates.Conclusion: The prevalence of ESBLs and MBLs-producing A. baumannii strains is a major concern and highlights the need of infection control measures including prompt identification of beta-lactamase-producing isolates and antibacterial management.

Backgrounds: The ever-increasing incidence of multidrug resistance in ESBL-producing Pseudomonas aeruginosa is one of the most serious public health threats. This study aimed to investigate the antibiotic resistance profile and molecular characteristics of ESBL-producing P. aeruginosa isolates. Materials & Methods: Antimicrobial susceptibility testing was performed for 120 P. aeruginosa clinical isolates using the Kirby-Bauer disk diffusion and broth microdilution assays. Combined disk test (CDT) was applied to screen for ESBL production among P. aeruginosa isolates. PCR assays determined the presence of blaGES, blaPER, and blaVEB genes in all isolates. Findings: The clinical isolates of P. aeruginosa showed the highest resistance to cefotaxime (86. 7%) and gentamicin (65. 8%). Of 120 P. aeruginosa isolates, 60. 8% were MDR, and 53. 3% were XDR. The prevalence of these strains was significantly higher in hospitalized patients than in out-patients (p<. 001). Also, 58 P. aeruginosa strains (48. 3%) were considered as phenotypic ESBL producers. Furthermore, 15, 35, and 24. 2% of P. aeruginosa isolates harbored blaGES, blaVEB, and blaPER, respectively. The incidence of MDR (71. 4% vs. 41. 9%, p=. 001) and XDR (63. 6% vs. 34. 9%, p=. 002) was significantly higher in ESBL-producing P. aeruginosa isolates compared to non-ESBL producers. The highest incidence rate of MDR was reported in blaVEB gene-positive P. aeruginosa isolates (95. 2%), followed by isolates harboring blaPER (79. 3%) and blaGES (55. 6%) genes. Conclusion: This study findings show a high prevalence of MDR ESBL-producing P. aeruginosa isolates, indicating the importance of correct identification of these superbugs and judicious use of various antibiotics to prevent their spread.

Aims: 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 blaTEM and blaVEB 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 blaTEM and blaVEB 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 (blaTEM and blaVEB) in A. baumannii strains. Conclusion: The high prevalence of blaTEM and blaVEB 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.

Background: Pseudomonas aeruginosa is a leading cause of nosocomial infections worldwide. Resistance of P. aeruginosa strains to the broad-spectrum cephalosporins may be caused by extended-spectrum b-lactamases (ESBLs).Objectives: The aim of this study was to determine the antimicrobial resistance patterns and prevalence of PER-1 and VEB-1 type genes among ESBL producing strains of P. aeruginosa.Material and Methods: A total of 106 P. aeruginosa isolates were collected from two university hospitals in Hamadan, Iran, during a7-month study (2009). The antimicrobial susceptibility of isolates was determined by disc diffusion method and interpreted according to the clinical and laboratory standards institute (CLSI) recommendations. Production of ESBL was determined by combined disk test and presence of PER-1 and VEB-1 type ESBL genes was identified by PCR.Results: The resistance against broad-spectrum cephalosporins and monobactames were: cefepime (97%), cefotaxime (92.5%) ceftazidime (51%), and aztreonam (27%). Ciprofloxacin (91.5%), imipenem (84.9%) and meropenem (82.1%) were the most effective anti-pseudomonas agents in this study. The results revealed that 88.7% of the isolates were multidrug resistant, 58.25% of those were ESBL positive. Sixteen (26.6%), 9 (15%) and 3 (5%) strains among ESBL-producing strains contained blaPER-1, blaVEB and blaPER-1-blaVEB, respectively.Conclusions: This study highlighted the need to establish antimicrobial resistance surveillance networks for P. aeruginosa to determine the appropriate empirical treatment regimens. The high prevalence of multidrug resistance and production of ESBLs in P. aeruginosa isolates confirms the necessity of protocols considering these issues in the hospitals.

Background: Acinetobacter has emerged as a significant opportunistic pathogen responsible for nosocomial infections. Treatment of infections due to this organism is becoming a serious clinical concern and these bacteria are frequently resistant to multiple classes of antibiotics such as Family of beta-lactam drugs. The b-lactamase enzymes represent the main mechanism of bacterial resistance to b-lactam antibiotics. This study was conducted to determine the prevalence of VEB and INT 1 in Acinetobacter isolates from sari hospital.Methods: The study included 100 Acinetobacter isolates that were isolated from various clinical specimens. Susceptibility of isolates to the antibiotics was determined by standard disk diffusion method. ESBL production was determined by combination disk method. Using disks containing ceftazidim and cefotaxim alone and incombination with Clavulanic acid and VEB and Integron class1 producing genes was detected by PCR test.Results: Among all Acinetobacter isolates, the highest resistance was observed for cefotaxime (100%), ceftazidim (100%), ceftraiaxone (96%), whereas the highest susceptibility was observed forcolistin (65%) Gentamycin (37%), tobramaycin (27%). Combined Disc Test showed that 24% of isolated were ESBL positive and among them 16.6% and 75% were positive for blaVEB and INT1 genes.Conclusion: According to the results, most of the isolates of acintobacter are drug resistant. The number of isolates of b lactamas producer is 24% of the total samples. Thus, other mechanisms such as secretory pump and purines can have a role in drug resistance.

Background: Pseudomonas aeruginosa is one of the main causes of nosocomial infections with a mortality rate up to 40-50%. Resistance to antibiotics is a global challenge in the treatment of infections caused by this bacterium. The Class A beta-lactamases genes, including blaSHV, blaPER, blaVEB, are the most common causes of resistance in this microorganism. This study was conducted to determine antibiotic resistance pattern and the presence of blaper, blaVEB, blashv and blaoxa-10 genes in clinical isolates of P. aeruginosa isolated from patients in a hospital in Bandar Abbas. Materials and Methods: This cross-sectional study was conducted on 72 P. aeruginosa clinical isolates. Antibiotic susceptibility testing was performed by disk diffusion method according to the clinical Laboratory Standard Institute. MIC (Minimum inhibitory concentration) of ceftazidime was performed by E-Test. Polymerase chain reaction (PCR) was performed to identify blashv, blaVEB-1, blaoxa-10, and blaper-1 genes. Results: Most of the isolates were detected from intensive care unit and urine samples. The highest resistance rate which was observed to sulfamethoxazole and ceftazidime, were 68 (94. 44%) and 44 (61. 11%), respectively. About 27. 8% of these isolates were multidrug resistant. Among 44 ceftazidime resistant isolates, 15 isolates (34%) showed MIC ≥ 32 μ g. mL in the E-test. The prevalence rates of genes were 4. 16, 12. 5, 8. 33, and 1. 38% for blaOxa-10, blaShv, blaVEB-1, and blaPer-1 genes, respectively. Conclusion: The ceftazidime resistance rate and the prevalence rate of resistance genes in the present study were lower than other Iranian studies. However, isolation of these genes is alarming that excessive use of antibiotics can lead to over expression of resistance genes and bacterial efflux pumps and the emergence of MDR phenotypes.

Background: Nowadays, the resistance of pathogenic bacteria to antibiotics has become a global problem. Acinetobacter baumannii is an important opportunistic nosocomial pathogen. Acinetobacter baumannii plays a significant role in antibiotic resistance. Objectives: The purpose of this study was to investigate the prevalence of the blaOXA-51, blaNDM, blaVIM, blaPER, blaVEB, blaCTX-M, tetA and tetB genes and antibiotic resistance pattern of A. baumannii isolated from hospitals in Tabriz city, Iran. Methods: This study was descriptive cross-sectional research, performed on 129 isolates of Acinetobacter from different clinical specimens. The Isolates were identified using standard laboratory methods and culture in selective mediums. The antibiotic resistance pattern of isolates was also determined by the Kirby-Bauer disk diffusion susceptibility test. Phenotypic and genotypic detection of blaOXA-51, blaNDM, blaVIM, blaPER, blaVEB, blaCTX-M, tetA and tetB genes in the isolates was carried out by a combined disk test (CDT) and polymerase chain reaction (PCR), respectively. Results: The highest resistance of isolates was determined to cefotaxime (100%) and ceftazidime (100%). The results of CDT showed that 14 (12. 96%) isolates could produce extended-spectrum Beta-lactamases (ESBLs). However, the PCR results blaOXA-51, blaNDM, blaVIM, blaPER, blaVEB, blaCTX-M, tetA and tetB genes showed that these genes were in 100%, 18. 51%, 16. 66%, 32. 40%, 16. 66%, 31. 48%, 32. 40% and 21. 29% of isolates, respectively. Conclusions: Due to the high prevalence of antimicrobial resistance in strains, rapid and timely detection of antibiotic-resistant A. baumannii strains is necessary for the selection of an appropriate therapeutic approach and prevention of their prevalence.