Journal of Medical Microbiology and Infectious Diseases
Volume:2 Issue: 4, Autumn 2014

There is not much data on parasitic infections of laboratory animals that are kept in conventional conditions in Iran. The present study was designed to investigate intestinal helminths infections in laboratory colonies of rats and mice.
Droppings from 110 mice and 110 rats (each animal one dropping) belonging to experimental and breeding groups in four animal houses were collected. Experimental groups were being used in biomedical researches and breeding groups were not under any experiment. The droppings were preserved in formaldehyde 10% individually and examined by microscopy with 10x magnification.
Out of 220 droppings examined, 96 (43.6%) harbored helminths eggs; 53 (48.1%) belonged to mice and 43 (39.09%) to rats. Four helminthes species including, Syphacia obvelata, Syphasia muris, Hymenolepis nana, and Hetrakis spumosa were identified in the both animals, while Aspicularis tetraptera was merely seen in mice. H. nana was the most frequent helminth infection in mice and rats and infection with H. spumosa and A. tetraptera, showed the lowest rates in droppings of mice and rats, respectively. Mixed infections with ≥ two species was observed in 21 (9.5%) of 220 droppings, 14 (12.7%) belonged to mice and 7 (6.3%) to rats.
The present results emphasizes more careful monitoring in laboratory animal houses, such as improving the cleaning and ventilating systems as well as adopting therapeutic measures, when required.

During the past few years, an increasing body of evidence has suggested a possible role for human herpes virus 6 (HHV-6) in Multiple Sclerosis (MS) pathogenesis. Despite the many reports supporting the relationship between HHV-6 and MS, this association has not been definitely proved or refuted, and the matter remains unresolved. The current study was aimed to investigate any relation between HHV-6 viremia and classic MS in patients in Guilan province, Northern Iran.
HHV-6 viremia was certified by molecular detection in study group (n=46) and control group (n=46) using nested-PCR. Data were analyzed by using three statistical tests (Chi square, odd ratio, and Relative Risk).
HHV-6 genomic sequences were found totally in 28 out of 46 (60.8%) plasma DNA samples of patients with MS, but were not found in rest of them. It was also found in 13 out of 46 (28.2%) control group. The difference in prevalence of HHV-6 DNA in blood between patients with MS and control group was statistically significant (P=0.0027 and odd ratio=0.277).
The data of our study showed that HHV-6 can be implicated in the development of MS. We strongly support the need for further, objective, evidence-based examination of the relationship between HHV-6 infection and MS.

In this study, the chemical composition and antimicrobial activity of essential oil of Ziziphora clinopodiodes and its potential application as a natural preservative in reducing the indigenous microbial population of hamburger were investigated.
Essential oil of Ziziphora clinopodiodes cultivated in Iran was obtained by Hydro-distillation method (HDM). Chemical composition of the oil was determined by gas chromatography/mass spectrometry (GC-MS) analysis. Antimicrobial activity of the essential oil was checked against Staphylococcus aureus, Escherichia coli, Bacillus subtilis, Salmonella typhi, Listeria monocytogenes, Pseudomonas aeruginosa, by using Agar dilution method (ADM). Minimum Inhibitory Concentration (MIC) values of each active oil concentration were determined and its potential application as a natural preservative in reducing the indigenous microbial population of hamburger was investigated.
The major components were carvacrol (54.31%), thymol (12.51%), octadecane (9.51%) and pulegone (4.88%). The results showed a significant activity against the tested strains (gram-positive and gram-negative bacteria). Addition of essential oil in concentration higher than MIC values reduced the microbial population of hamburgers stored at 25°C, 4°C and -12°C. In samples refrigerated at 4°C, differences between the controls and samples treated with essential oil at MIC values (0.20 and 0.4 mg/ml) were not significant during the first 24 h (p> 0.05), but higher concentration of essential oil resulted in about 2 to 3 log reduction in total microorganisms.
This study showed that the Ziziphora clinopodiodes essential oil can be added to the ingredients of foods as the natural antibacterial agent.

This study is aimed to compare phenotypic test methods and determine antibiotic susceptibility pattern of AmpC beta-lactamase producing uropathogenic Escherichia coli and Klebsiella pneumoniae in clinical isolates.
E. coli and K. pneumoniae were identified by standard microbiological procedures. Screening of AmpC beta-lactamase production was done by using cefoxitin disc (30 µg) showing inhibition zone diameter of A total of 120 Gram Negative Rods (GNRs) were included in the study. Amongst them cefoxitin resistant isolates were 68.33% (n=82/120). In these 82 isolates, E. coli were n=57 (69.51%) and K. pneumoniae were n=25 (30.48%). DAT identified 52.43% of AmpC beta-lactamase producing isolates, sensitivity of DAT was found to be 88% with 92% specificity, Positive Predictive Value of 92.68%, Negative Predictive Value of 87.80%, and Diagnostic Accuracy of 90.24%. Antibiotic susceptibility testing by Kirby Bauer Disc diffusion technique showed that carbapenems (meropenem) and tigecycline were of higher therapeutic effects against these resistant pathogens.
Introducing simple tests like DAT in the laboratories can control the spread of AmpC beta-lactamase harboring organisms. Carbapenems (meropenem) and tigecycline are of suitable therapeutic effect against these resistant pathogens.

The major resistance mechanisms of Pseudomonas aeruginosa to fluoroquinolones and carbapenems are associated with the mutations in the genes gyrA and oprD encoding type II topoisomerases (DNA gyrase) and OprD porin, respectively.
In this cross-sectional study, sixty five clinical samples were collected from patients hospitalized in Al-Zahra Hospital of Isfahan, Iran. Susceptibility testing was performed by using disk diffusion and minimum inhibitory concentration (MIC) by E-test methods as recommended by Clinical Laboratory Standards Institute (CLSI). The assay was based on a DNA sequencing method using polymerase chain reaction (PCR).
The disk diffusion and E-test methods showed significant concordance in determining the in-vitro activity of the meropenem and ciprofloxacin against P. aeruginosa isolates. The mutations associated with antibiotic resistance were detected in the codon 83 of the gyrA gene, and various codons of the oprD gene.
Our results showed that the main mechanism of fluoroquinolone resistance in P. aeruginosa is mediated primarily through mutations in gyrA and carbapenem resistance was driven mainly by the mutational inactivation of oprD gene.

Extended spectrum beta-lactamase (ESBL) producing Escherichia coli generate a major problem for clinical therapeutics and epidemiological study. The incidence of ESBL producing strains among clinical isolates has been steadily increasing during the past few years, and remains an important cause of failure of therapy with cephalosporins. The aim of this study was to determine the antimicrobial susceptibility pattern and prevalence of ESBLs in E. coli isolates taken from different clinical specimens by phenotypic and genotypic techniques.
In this descriptive study, a total of 100 E. coli isolates collected from different clinical specimens were used. The antibiotic resistance pattern to twelve antimicrobial agents was determined by disk diffusion method. The ESBLs producing strains were confirmed by double-disk-diffusion test, and the CTX-M, TEM, SHV, and OXA were detected by PCR.
The prevalence of ESBL producing E. coli was 56%. The results show that 95% of ESBL producing E. coli isolates tested were resistant to ceftriaxone and cefotaxime, 93% for ceftazidime, 86% for azithromycin, 79% for cefazolin and 43% to imipenem. Among the ESBL producing E. coli, 48%, 30% and 11% were positive for CTX-M, TEM and SHV genes, respectively. OXA was not found in all isolates.
ESBL producing isolates of E. coli have been increasingly recognized and there is a need to carefully formulate therapeutic strategies to control infections in teaching Hospitals. The high percentage of drug resistance in ESBL producing E. coli suggests that routine detection of ESBL is required by reliable laboratory methods.

This study was intended to determine the presence and distribution of Listeria monocytogenes in various meat and dairy products from Qazvin Province by culture followed by biochemical and morphological assays. The identity of the isolates was further obtained by amplification of prfA gene in bacteria isolates. This gene is a transcriptional activator of virulence gene expression within the pathogenic L. monocytogenes.
In a cross-sectional design, a total of 182 different food samples were collected from different areas in Qazvin, Iran. Bacterial isolates were obtained by the cold enrichment method. DNA extraction from the pelleted cells was conducted and then prfA gene was amplified by conventional PCR.
As many as 37 (20.3%) food samples were positive for Listeria spp. including 21 (56.8%) L. monocytogenes, 7 (18.9%) Listeria innocua, 4 (10.8%) Listeria welshimri, 3 (8.1%), Listeria seligeri, and 2 (5.4%) Listeria grayi. None of the isolated specimen was Listeria ivanovii. The PrfA gene was amplified in all L. monocytogenes specimen. Moreover, PCR assay had high sensitivity and specificity for bacterial identification.
To sum up, presence of L. monocytogenes in food samples was confirmed in this region, it was more frequent in milk specimen. In addition to common culture techniques, PCR assay showed higher sensitivity and specificity for L. monocytogenes detection in contaminated foods.

Acinetobacter baumannii, a known causative agent of nosocomial infections, is one of the highly antibiotic-resistant gram-negative bacilli. Carbapenem-resistant Acinetobacter isolates are increasingly reported worldwide. Carbapenems such as imipenem and meropenem are efficient antimicrobial agents commonly used for the treatment of infections caused by multi- resistant A. baumannii strains. Some reports indicate treatment failure due to antibiotic resistant A. baumannii strains. The aim of this study was to determine antibiotic resistance pattern and prevalence carbapenemase production in A. baumannii isolates.

A total of 100 A. baumannii isolates were identified from clinical specimens by standard chemical tests. The samples were collected from the patients hospitalized in two teaching hospitals of Ahvaz, southwestern of Iran. The susceptibility of isolates to different antibiotics was determined by the disk diffusion method based on Clinical Laboratory Standards Institute (CLSI) direction. The Modified Hodge Test (MHT) was performed for detection of carbapenemase - producing A. baumannii isolates.

The isolates showed the highest resistance to ciprofloxacin (98%). The resistance rate to cefotaxime, ceftazidime, and piperacillin was 97%, gentamicin, amikacin, and meropenem 96%, imipenem 95%, cefepime 93%, and tetracycline 60%. Most of the isolates (99%) were sensitive to colistin. Among the100 A. baumannii isolates, 53 (53%) were positive for carbapenemase production by MHT.

This study emphasizes dissemination of carbapenem resistant A. baumannii strains. Our study also showed that the MHT has an excellent sensitivity for detecting carbapenemase - producing A. baumannii isolates.