Seroprevalence of Brucellosis in Human Immunodeficiency Virus Infected Patients in Hamadan, Iran

OBJECTIVES: Brucellosis is a systemic disease with a wide spectrum of clinical manifestations. This study aimed to determine the seroprevalence of brucellosis in human immunodeficiency virus (HIV) infected patients in Hamadan Province in the west of Iran. METHODS: A total of 157 HIV-infected patients were screened through standard serological tests, including Wright’s test, Coombs’ Wright test, and 2-mercaptoethanol Brucella agglutination test (2ME test), blood cultures in Castaneda media, and CD4 counting. Data were analyzed using Stata version 11. RESULTS: Wright and Coombs’ Wright tests were carried out, and only 5 (3.2%) patients had positive serological results. However, all patients had negative 2ME results, and blood cultures were negative for Brucella spp. Moreover, patients with positive serology and a mean CD4 count of 355.8 ± 203.11 cells/μL had no clinical manifestations of brucellosis, and, and the other patients had a mean CD4 count of 335.55 ± 261.71 cells/μL. CONCLUSION: Results of this study showed that HIV infection is not a predisposing factor of acquiring brucellosis.

Spread of Efflux Pump Overexpressing-Mediated Fluoroquinolone Resistance and Multidrug Resistance in Pseudomonas aeruginosa by using an Efflux Pump Inhibitor

BACKGROUND: Fluoroquinolone resistance in Pseudomonas aeruginosa may be due to efflux pump overexpression and/or target mutations. We designed this study to investigate the efflux pump mediated fluoroquinolone resistance and check the increasing effectiveness of fluoroquinolones in combination with an efflux pumps inhibitor among P. aeruginosa isolates from burn wounds infections. MATERIALS AND METHODS: A total of 154 consecutive strains of P. aeruginosa were recovered from separate patients hospitalized in a burn hospital, Tehran, Iran. The isolates first were studied by disk diffusion antibiogram for 11 antibiotics and then minimum inhibitory concentration (MIC) experiments were performed to detect synergy between ciprofloxacin and the efflux pump inhibitor, carbonyl cyanide-m-chlorophenyl hydrazone (CCCP). Then to elucidate the inducing of multi drug resistance due to different efflux pumps activation in Fluoroquinolone resistant isolates, synergy experiments were also performed in random ciprofloxacin resistant isolates which have overexpressed efflux pumps phenotypically, using CCCP and selected antibiotics as markers for Beta-lactams and Aminoglycosides. The isolates were also tested by polymerase chain reaction (PCR) for the presence of the MexA, MexC and MexE, which encode the efflux pumps MexAB-OprM, MexCD-OprJ and MexEF-OprN. RESULTS: Most of the isolates were resistant to 3 or more antibiotics tested. More than half of the ciprofloxacin resistant isolates exhibited synergy between ciprofloxacin and CCCP, indicating the efflux pump activity contributed to the ciprofloxacin resistance. Also increased susceptibility of random ciprofloxacin resistant isolates of P. aeruginosa to other selected antibiotics, in presence of CCCP, implied multidrug extrusion by different active efflux pump in fluoroquinolones resistant strains. All of Ciprofloxacin resistant isolates were positive for MexA, MexC and MexE genes simultaneously. CONCLUSION: In this burn hospital, where multidrug resistant P. aeruginosa isolates were prevalent, ciprofloxacin resistance and multidrug resistance due to the overexpression of fluoroquinolones mediated efflux pumps has also now emerged. Early recognition of this resistance mechanism should allow the use of alternative antibiotics and use an efflux pumps inhibitor in combination with antibiotic therapy.

[Risk factors and antimicrobial susceptibility in ventilator associated pneumonia: a brief report]

Ventilator associated pneumonia [VAP] is one of the serious complications of ventilatory support, occurring in ICUs. The aim of this study was to determine various risk factors associated with the acquisition of Acinetobacter infection and its antimicrobial susceptibility pattern. This cross-sectional study was performed in the ICUs of Rasoul-e-Akram Hospital in Tehran, Iran during the year 2011. A total of 51 endobronchial aspirates from intubated patients who had been clinically diagnosed to have VAP were studied bacteriologically. The in vitro susceptibility was determined by disk-diffusion and broth microdilution MIC methods. Out of 51 patients with VAP, 35 [66.66%] had positive cultures for Acinetobacter species. In vitro susceptibility test revealed that a high percentage of isolates were resistant to imipenem, piperacillin-tazobactam, third generation cephalosporines, and aminoglycosides. The antimicrobial resistance of gram negative bacteria, particularly Acinetobacter species, is increasing and preventive measures need to be taken as a matter of urgency.

Investigation of class I, II and III integrons among acinetobacter strains isolated from ventilator-associated pneumonia patients in intensive care unit of Rasoul Akram Hospital in Tehran, Iran

Multi-drug resistant strains of Acinetobacter spp. have created therapeutic problems worldwide. The objective of this study was to detect integrons in Acinetobacter spp. isolates from Ventilator-Associated Pneumonia patients using PCR method. A total 51 Bronchoalveolar lavage samples were obtained from patients in ICU and examined for Acinetobacter spp. infection by biochemical and PCR methods using blaOXA51-like primers. Antimicrobial susceptibility testing was performed using disk diffusion and MIC methods. Among 51 patients with VAP [62.7% males, 35.2% females, mean age 53 year], 50 [98%] were positive, with a high prevalence of gram-negative bacteria, mainly Acinetobacter spp. [70%], from which A. baumani was detected in 34 [68%] and A. lwoffii in 1 [2%] of isolates. More than 90% of isolates were resistant to imipenem, piperacillin+tazobactam, third generation cephalosporins and gentamicin, while the most effective antibiotic was colistin [100%]. The correlation coefficient between disk diffusion and MIC was 0.808 [p = 0.001]. Three Acinetobacter isolates [8%] harbored integrase /gene but none of isolates contained Class II or III integrons. The results showed that colistin was an effective antibiotic and can be used for treatment of patients in ICU. Due to the high number of MDR isolates lacking Integrons it can be concluded that although class I integrons are important among clinical isolates of A. baumannii, they have no significant role in dissemination of antibiotic resistance genes in Rasoul Akram Hospital in Tehran, Iran. The presence of IntI in A. Iwoffii may be related to transfer of integron to A. baumannii which can be considered as an important threat for hospitalized patients