ABSTRACT
Metronidazole is a main stay of modern multidrug therapies for Helicobacter pylori [H. pylori] infection. Metronidazole resistance reduces the effectiveness of these combination therapies. Various methods have been used for the determination of the sensitivity of H. pylori to metronidazole, that have shown conflicting results. The aims of this study are: 1] Comaring E-Test and disk diffusion methods for determining the susceptibility of H. pylori to metronidazole; and 2] As metronidazole resistance in H. pylori has been found to be associated with mutations in rdxA, the role of this gene in metronidazole resistance in H. pylori has been examined in this study. A total of 46 H. pylori strains from 223 consecutive patients were examined. The E-Test was performed according to the manufacturer's guidelines, and the disk diffusion test, according to standard procedure, using 5 micro g metronidazole disks. Extraction of DNA was done from all H. pylori isolates by boiling and the use of phenol-chloroform methods, and afterwards Polymerase Chain Reaction [PCR] was performed. Metronidazole resistance as determined by E-test and disk diffusion methods, was 64.3% and 47.6% respectively. None of the resistant or sensitive samples possessed rdxA gene deletion. Disk diffusion method is not reliable in determining metronidazole resistance in H. pylori. An intact rdxA gene has also been reported in metronidazole-resistant H. pylori, suggesting that additional metronidazole resistance mechanisms exist in H. pylori and even molecular methods are not reliable for the detection of this resistance
ABSTRACT
Background and Aim: The emergence of nonfermenter bacteria that are resistant to multidrug resistant ESBL are nowadays a principal problem for hospitalized patients. The present study aimed at surveying the emergence of nonfermenter bacteria resistant to multi-drug ESBL producing isolated from patients blood samples using BACTEC 9240 automatic system in Shiraz
Materials and Methods: In this cross-sectional study, 4825 blood specimens were collected from hospitalized patients in Shiraz [Iran], and positive samples were detected by means of BACTEC 9240 automatic system. The isolates containing nonfermenter bacteria were identified based on biochemical tests embedded in the API-20E system. Antibiotic sensitivity test was performed and identification of ESBL producing strains were done using phenotypic detection of extended spectrum beta-lactamase producing isolates [DDST] according to CLSI [2013]guidelines
Results: Out of 4825 blood samples, 1145 [24%] specimen were gram-positive using BACTEC system
Among all isolated microorganisms, 206 isolates were non-fermenting gram- negative bacteria
The most common non-fermenter isolates were Pseudomonas spp. [48%], Acinetobacter spp. [41.7%] ,and Stenotrophomonas spp. [8.2%]. Seventy of them [81.4%] were Acinetobacter spp. which were ESBL positive. Among beta-lactam antibiotics, Pseudomonas spp. showed the best sensitivity to piperacillintazobactam [46.5%]
Conclusion: It was found that ?-lactam antibiotics are not effective against more than 40% of Pseudomonas spp. infections and 78% Acinetobacter infections. Emergence of multi-drug resistant strains that are resistant to most antibiotic classes is a major public health problem in Iran. To resolve this problem using of practical guidelines is critical
ABSTRACT
Background: Appropriate diagnosis and treatment of latent tuberculosis infection [LTBI] play the most important role in the control of tuberculosis. This study aimed to determine the prevalence of LTBI among healthy tuberculosis unexposed children vaccinated with BCG using the tuberculin skin test [TST] and QuantiFERON TB Gold In-Tube [QFT-GIT] and comparing the agreement between the two tests
Methods: Across-sectional study was carried out between October 2009 and March 2010 in 24 schools and 11 daycare centers. A total of 967 children were divided into 15 age groups, with a minimum of 64 children per group
Results: The prevalence rates of LTBI with TST were 3.8%, and 2.2% with QFT-GIT. One case was positive in TST and QFT-GIT, 20 cases were QFT-GIT positive, but TST negative and 36 cases were TST positive, but QFT-GIT negative, and finally, 910 cases were negative in both. There was poor agreement between TST and QFT-GIT [1.8%, 95%, CI: 0%-5.3%, k-0.007]. The specificity of QFT-GIT in the BCG vaccinated, children aged 1-15 years old, was 97.8% [97.8%, 95% CI: 96.8%-98.8%]. After three months, 2/17[11.8%] of those initially QFT-GIT negative converted, and 10/15 [66%] of those initially QFT-GIT positive reverted
Conclusion: It seems that TST and QFT-GIT are not appropriate tests for the diagnosis of LTBI among healthy tuberculosis unexposed BCG vaccinated children. There was a low reproducibility rate of QFT-GIT. The cause of the the poor agreement requires further studies
ABSTRACT
Tuberculin skin test [TST] is a readily available test for the diagnosis of latent tuberculosis infection [LTBI]. This study was designed to evaluate LTBI in low-risk children aged 1-15 years. This cross-sectional study was performed in Shiraz, Iran, over six months during 2009. Totally, 1289 boys and girls were selected by stratified multistage random sampling from four municipality areas before allocating them to 15 groups. Inclusion criteria included age 1-15 years, documented history of BCG vaccination at birth, Iranian nationality and a healthy state of being. Children with acute febrile diseases, immunosuppression, on medication and immigrants were excluded. We considered a TST >/= 10 mm of induration as positive. The prevalence of LTBI in 1-15 years old children was 4.5%. The percentage was 3.5% in 1-5 year old, 4.1% in 6-10 year old and 5.7% in 11-15 year old children. The highest rate of infection was 9.8% in 15 year olds and the lowest was 2.2% in 3-year old children. Gender had no effect on LTBI rate. There is no significant difference of LTBI prevalence between four municipality areas. The prevalence of LTBI in this study was lower in comparison with other studies performed in Iran. Positive predictive value of TST decreases in low endemic areas for tuberculosis, especially in low-risk groups; therefore, most positive results are false-positive created by nonspecific reactions and infection with environmental mycobacteria. Hence, there is a need for new diagnostic tools that are easy and cost-effective
ABSTRACT
Nosocomial infection caused by methicillin-resistant staphylococci poses a serious problem in many countries. The aim of this study was to rapidly and reliably detect methicillin-resistant-staphylococci in order to suggest appropriate therapy. The presence or absence of the methicillin-resistance gene in 115 clinical isolates of Staphylococcus aureus and 50 isolates of Coagulase Negative Staphylococci [CNS] was examined by normal PCR. DNA extraction for PCR performance was then modified by omission of achromopeptadiase and proteinase K digestion, phenol/chloroform extraction and ethanol precipitation. All isolates with MIC>8 micri g/ml showed positive PCR. No differences in PCR detection have been observed when normal and modified DNA extractions have been performed. Our modified DNA extraction can quickly detect methicillin-resistant staphylococci by PCR. The advantage of rapid DNA extraction extends to both reduction of time and cost of PCR performance. This modified DNA extraction is suitable for different PCR detection, when staphylococci are the subject of DNA analysis