Iranian Journal of Microbiology
Volume:1 Issue: 1, Mar 2009

Crimean- Congo Hemorrhagic Fever (CCHF) is a viral zoonotic tick-born disease with a mortality rate of up to 50% in humans. After a short incubation period, the disease is characterized by sudden fever, chills, severe headache, dizziness, back, and abdominal pain. Additional symptoms can include nausea, vomiting, diarrhea, neuropsychiatric, and cardiovascular changes. In severe cases, hemorrhagic manifestations, ranging from petechiae to large areas of ecchymosis develop. The CCHF Virus (CCHFV) is from the genus Nairovirus and family Bunyaviridae. CCHFV is transmitted to humans by the bite of infected tick and by direct contact with blood or tissue from infected humans and livestock. In addition to zoonotic transmission, CCHFV can be spread from person to person and is one of the rare hemorrhagic fever viruses able to cause nosocomial outbreaks in hospitals. CCHF is a public health problem in many regions of the world e.g Eastern Europe, Asia, Middle East, and Africa. The history of CCHF in Iran shows that the disease has been detected in Iran since 1970. From 1970 to 1978 some scientists worked on serology and epidemiology of this disease in humans and livestock in Iran. Since 1999, establishment of a surveillance and laboratory detection system on viral hemorrhagic fevers particularly on CCHF has had benefits. One of which is the fact that a mortality rate approaching 20% in the year 2000 remarkably dropped to 6% in the year 2007.

The aim of this study was to investigate the significance of multiple-mutations in the katG gene, predominant nucleotide changes and its correlation with high level of resistance to isoniazid in Mycobacterium tuberculosis isolates that were randomly collected from sputa of 42 patients with primary and secondary active pulmonary tuberculosis from different geographic regions of Belarus. Drug susceptibility testing was determined using the CDC standard conventional proportional method. DNA extraction, katG amplification, and DNA sequencing analysis were performed. Thirty four (80%) isolates were found to have multiple-mutations (composed of 2-5 mutations) in the katG. Increased number of predominant mutations and nucleotide changes were demonstrated in codons 315 (AGC→ACC), 316 (GGC→AGC), 309 (GGT→GTT) with a higher frequency among patients bearing secondary tuberculosis infection with elevated levels of resistance to isoniazid (MIC μg/ml ≥ 5-10). Furthermore it was demonstrated that the combination of mutations with their predominant nucleotide changes were also observed in codons 315, 316, and 309 indicating higher frequencies of mutations among patients with secondary infection respectively. In this study 62% (n=21) of multi-mutated isolates found to have combination of mutations with predominant nucleotide changes in codons 315 (AGC→ACC), 316 (GGC→GTT), 309 (GGT→GGT), and also demonstrated to be more frequent in isolates of patients with secondary infections, bearing higher level of resistance to isoniazid (≥ 5 -10μg/ml).

Helicobacter pylori causes chronic gastritis, peptic ulceration, and is a risk factor for gastric cancer. More than half of the world`s population is infected with this pathogen, however the disease outcome varies. Among the virulence factors of H. pylori, specific adhesions to gastric epithelium may be an important step in the induction of active inflammation. H. pylori displays considerable genetic diversity attributed to genetic drift during long-term colonization. Heterogeneity of clinical-isolates has considerably impacted in understanding the role of each factor in infection outcome. However, genetic change may be more limited in the stomach of children in the short period after infection. This work evaluates differences in adherence potential of strains isolated from children with various chronic- inflammation status. A total of 157 children admitted to Medical Center of Tehran for upper gastrointestinal problems underwent endoscopy for H. pylori infection. Histological examination of their biopsies was performed after H& E and Giemsa staining. Gastritis and inflammation were graded according to the updated Sydney system. 70 culture-positive children, 20 were selected according to their histopathological status. Adherence of their H. pylori isolates to HEp- 2 cells was evaluated by viable count of bacteria associated with host cells in an optimized procedure developed in this study. Correlation was seen between inflammation severity score and efficiency of adhesion to HEp-2 cells. This correlation was not observed in the KB cell line as an epithelial cell-model. Specific interaction of H. pylori with host gastric epithelium may be associated with disease outcome

Chlamydiae are obligate intracellular bacterial pathogens that share a unique developmental cycle. The cycle alternates between infectious extracellular elementary bodies (EBs) and metabolically active reticulate bodies (RBs), which multiply within intracellular vacuoles known as inclusions. Recent evidence has demonstrated that C. pneumoniae is present and persistent at active sites of infection and thus contributes to coronary artery and respiratory diseases, the leading causes of death in the developed world. To understand the process of Chlamydia infection, it is important to investigate the morphology of both normal and infected Hep-2 cells. Hep-2 cell lines (ATCC CCL23) were obtained from the Virology Laboratory, King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Cells were grown on cover-slip in shell vial at 37oC in 5% CO2 humidified atmosphere. Later C. pneumoniae were inoculated in the cell lines. The infected cells were scanned using transmission electron microscopy (TEM). TEM showed round shaped cells with a smooth surface. Some holdings were observed on the edges which are believed to be due to the fluidity of the cytoplasm membrane. The TEM micrograph revealed smooth membrane and typical eukaryotic undisturbed organelles. The morphology of C. pneumoniae, the reticulate bodies (RBs), the elementary bodies (EBs), and their diameter with loug axis were determined. Despite the presence of inclusion bodies within the cytoplasm of the majority of the infected cells, an alternating period of host cell destruction and host cell proliferation was observed. We termed this phenomenon as unsuccessful infection (USI).

Sub inhibitory concentrations (sub-MICs) of antibiotics, although unable to kill bacteria, can modify their physiologic and biochemical integrity and may to some extent interfere with some bacterial functions. In this study the effect of penicillin, vancomycin, and ceftazidime were evaluated on two pathogenic and commonly encountered bacterial species in clinical practice. The test bacterial strains included Staphylococcus aureus ATCC 29213 and Pseudomonas aeruginosa ATCC 2783. In this study, coagulase and DNase activity, mannitol fermentation and morphologic change of S. aureus and oxidase activity, pigment production and morphologic change of P. aeruginosa were evaluated. Except for some changes in the morphology being apparent as enlarged and undivided cocci in 1/2 to 1/8 sub MIC of all above-mentioned antibiotics, S. aureus showed no change in any of its properties, like coagulase and DNase production and mannitol fermentation. In P.aeuginosa, except for some morphologic changes, i.e. elongation and filamentation, in 1/2 to 1/8 dilution of ceftazidime, no further changes were observed. Exposure of bacteria to sub MICs of antibiotic can produce some detectable morphologic changes without any alteration in other biochemical properties.

β-lactamase production is the predominant mechanism for resistance to β-lactams in Enterobacteriaceae. The producing isolates are often multidrug resistant and are major hosts for extended spectrum β-lactamases. This study was designed to determine the prevalence of extended-spectrum β-lactamase producing isolates of Escherichia coli and Klebsiella pneumoniae and their antibiotic resistance patterns in Semnan, Iran. 275 Escherichia coli and 107 K. pneumoniae isolates from clinical specimens were investigated. Combined disk test was used as a screening test for ESBL production. Disk diffusion test was performed for antibiotic susceptibility testing. The greatest resistance was observed against ampicillin (96.3%) and the least resistance was against ceftazidime (16.5%). Using combined disks as phenotypic confirmatory test, ESBL were detected among 69 (18.1%) of all isolates. Frequency of ESBL production was 17.45% and 19.6% for E. coli and K. pneumoniae respectively. High levels of resistance and ESBL production found in the E. coli and K. pneumoniae in this study make the choice of empirical antibiotic regimens difficult. Antimicrobial susceptibility testing and ESBL production monitoring are recommended in patients

A six month old male hamster living in a colony of Hamster in the animal house of Urmia University, Urmia, Iran, was found with restlessness and circling signs. The clinical examination revealed symptoms and signs of encephalitis. Therefore microbiological and histopathologic studies were conducted after euthanizing the animal. Finally, the results of laboratory tests demonstrated Listeria monocytogenes infection in the Hamster.