Bacteria Isolated from urinary tract infection among patients and determination of the antibiotic susceptibility patterns of the gram negative bacteria in Iran

Background: Escherichia coli [E. coli] is the most frequent infecting organism in acute infection. So, knowledge about the frequency and distribution of urinary tract infection [UTI] is important to improve infection control measures. The aim of this research was to determine the prevalence of bacteria isolated from urinary tract infection [UTI] in patients and determination of the antibiotic susceptibility patterns of the gram negative bacteria

Materials and Methods: This descriptive study was performed in Imam Reza hospital, Tabriz [northwest of Iran] during March 2012 to February 2013. We surveyed 8153 patients, who had clinical manifestations of UTI. 5093 [62.47%] of them were female and 3060 [37.53%] of them male. Urine specimens were cultured for isolation of the microbial agents of UTI. The isolated bacteria were identified using biochemical tests. Disk diffusion susceptibility test was used to determine antimicrobial susceptibility

Results: E. coli [55.38%] was the most common isolated pathogen, followed by Enterobacter spp. [29.61%], Pseudomonas spp. [4.9%], S. aureus [3.21%], Enterococcus spp. [2.3%], fungi [1.5%] and Klebsiella [0.48%]. The sensitivity rates of isolated gram negative bacteria were for Amikacin [95.7%], Nitrofurantoin [91.5%], Gentamicin [64.1%], Ceftizoxim [56.8%], Ciprofloxacin [37.6%], Cotrimoxazole [31.4%] and Nalidixic acid [23.5%]

Conclusion: This study showed that the frequency of E. coli and Enterobacter spp. increases the probability of urinary tract infection. Also this survey indicates the emergence of antibiotic resistant infections in the studied hospital. So, there is a need to improve the effectiveness of integrated infection control programs to control and manage nosocomial infections caused by highly resistant organisms

ELISA cut-off point for the diagnosis of human brucellosis; a comparison with serum agglutination test

Brucellosis is a world-wide disease, which has a diverse clinical manifestation, and its diagnosis has to be proven by laboratory data. Serum agglutination test [SAT] is the most-widely used test for diagnosing brucellosis. The enzyme linked immunosorbent assay [ELISA] can also determine specific antibody classes against brucella. It is a sensitive, simple and rapid test, which could be an acceptable alternative to SAT with fewer limitations, however, like any other new test it should be further evaluated and standardized for various populations. This study was planned to determine an optimal cut-off point, for ELISA which would offer maximum sensitivity and specificity for the test when compared to SAT. Four hundred and seven patients with fever and other compatible symptoms of brucellosis were enrolled in the study. Serum agglutination test, 2-Mercaptoethanol test, and ELISA were performed on their sera. The cut-off point of 53 IU/ml of ELISA-IgG yielded the maximal sensitivity and specificity comparing to the other levels of ELISA-IgG, and was considered the best cut offpoint of ELISA-IgG to diagnose acute brucellosis. At this cutoff, the sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were 84.09%, 85.38%, 62.20, 94.90, 5.75, 0.18, respectively. The best cut-off point of ELISA-IgG is 53 IU/ml, which yields the maximal sensitivity and specificity to diagnose acute brucellosis