| Mohammad Mehdi Soltan Dallal | 2 Articles |
<sec><b>Objectives</b><p>The genus <italic>Shigella</italic> comprises the most infectious and diarrheagenic bacteria causing severe diseases, mostly in children under five years of age. This study aimed to detect nine virulence genes (<italic>ipaBCD</italic>, <italic>VirA</italic>, <italic>sen</italic>, <italic>set1A</italic>, <italic>set1B</italic>, <italic>ial</italic>, <italic>ipaH</italic>, <italic>stx</italic>, and <italic>sat</italic>) in <italic>Shigella</italic> species (spp.) using multiplex polymerase chain reaction (MPCR) and to determine the relation of <italic>Shigella</italic> spp. from pediatric diarrheal samples with hospitalization and bloody diarrhea in Tehran, Iran.</p></sec><sec><b>Methods</b><p><italic>Shigella</italic> spp. were isolated and identified using standard microbiological and serological methods. The virulence genes were detected using MPCR.</p></sec><sec><b>Results</b><p>Seventy-five <italic>Shigella</italic> spp. (40 <italic>S. sonnei</italic>, 33 <italic>S. flexneri</italic>, 1 <italic>S. dysenteriae</italic>, and 1 <italic>S. boydii</italic>) were isolated in this study. The prevalence of <italic>ial</italic>, <italic>sen</italic>, <italic>sat</italic>, <italic>set1A</italic>, and <italic>set1B</italic> was 74.7%, 45.4%, 28%, 24%, and 24%, respectively. All <italic>S. flexneri</italic> isolates, while no <italic>S. sonnei</italic>, <italic>S. dysenteriae</italic>, or <italic>S. boydii</italic> isolates, contained <italic>sat</italic>, <italic>set1A</italic>, and <italic>set1B</italic>. All isolates were positive for <italic>ipaH</italic>, <italic>ipaBCD</italic>, and <italic>virA</italic>, while one (1.4%) of the isolates contained <italic>stx</italic>. The highest prevalence of virulence determinants was found in <italic>S. flexneri</italic> serotype IIa. Nineteen (57.6%) of 33 <italic>S. flexneri</italic> isolates were positive for <italic>ipaBCD</italic>, <italic>ipaH</italic>, <italic>virA</italic>, <italic>ial</italic>, and <italic>sat</italic>. The <italic>sen</italic> determinants were found to be statistically significantly associated with hospitalization and bloody diarrhea (<italic>p</italic> = 0.001).</p></sec><sec><b>Conclusion</b><p>This study revealed a high prevalence of enterotoxin genes in <italic>S. flexneri</italic>, especially in serotype 2a, and has presented relations between a few clinical features of shigellosis and numerous virulence determinants of clinical isolates of <italic>Shigella</italic> spp.</p></sec>
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<sec><b>Objectives</b><p>Gastrointestinal disorders caused by <italic>Salmonella enterica</italic> serovar Enteritidis (<italic>Se</italic>sE) are a significant health problem around the globe. Probiotic bacteria have been shown to have positive effects on the immune responses. <italic>Lactobacillus acidophilus</italic> was examined for its capability to influence the innate immune response of HT29 intestinal epithelial cells towards <italic>Se</italic>sE. The purpose of this work was to assess the effect of <italic>L. acidophilus</italic> PTCC 1643 on cultured intestinal epithelial cells infected with <italic>Se</italic>sE.</p></sec><sec><b>Methods</b><p>HT29 cells were cultured in Roswell Park Memorial Institute medium supplemented with 10% fetal bovine serum and 1% penicillin/streptomycin. The cells were treated with <italic>L. acidophilus</italic> PTCC 1643 after or before challenge with <italic>Se</italic>sE. At 2 and 4 hours post-infection, we measured changes in the expression levels of <italic>TLR2</italic> and <italic>TLR4</italic> via real-time polymerase chain reaction.</p></sec><sec><b>Results</b><p>Treatment with <italic>L. acidophilus</italic> inhibited <italic>Se</italic>sE-induced increases in <italic>TLR2</italic> and <italic>TLR4</italic> expression in the infected HT29 cells. Moreover, the expression of <italic>TLR2</italic> and <italic>TLR4</italic> in cells that were pretreated with <italic>L. acidophilus</italic> and then infected with <italic>Se</italic>sE was significantly higher than that in cells infected with <italic>Se</italic>sE without pretreatment. Taken together, the results indicated that <italic>L. acidophilus</italic> had an anti-inflammatory effect and modulated the innate immune response to <italic>Se</italic>sE by influencing <italic>TLR2</italic> and <italic>TLR4</italic> expression.</p></sec><sec><b>Conclusion</b><p>Our findings suggested that <italic>L. acidophilus</italic> PTCC 1643 was able to suppress inflammation caused by <italic>Se</italic>sE infection in HT29 cells and reduce <italic>TLR2</italic> and <italic>TLR4</italic> expression. Additional in vivo and in vitro studies are required to further elucidate the mechanisms underlying this anti-inflammatory effect.</p></sec>
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| Mohammad Mehdi Soltan Dallal | 1 Article |
<b>Objectives</b><br/>
Production of carbapenemase, especially <i>Klebsiella pneumoniae</i> carbapenemases (KPC), is one of the antibiotic resistance mechanisms of Enterobacteriaceae such as <i>Klebsiella oxytoca</i>. This study aimed to investigate and identify KPC-producing <i>K. oxytoca</i> isolates using molecular and phenotypic methods.<br/><b>Methods</b><br/>
A total of 75 isolates of <i>K. oxytoca</i> were isolated from various clinical samples, and were verified as <i>K. oxytoca</i> after performing standard microbiological tests and using a polymerase chain reaction (PCR) method. An antibiotic susceptibility test was performed using a disc diffusion method according to the Clinical and Laboratory Standards Institute guidelines. CHROMagar KPC chromogenic culture media was used to examine and confirm the production of the carbapenemase enzyme in <i>K. oxytoca</i> isolates; in addition, PCR was used to evaluate the presence of <i>bla</i><sub>KPC</sub> gene in <i>K. oxytoca</i> strains.<br/><b>Results</b><br/>
Of a total of 75 <i>K. oxytoca</i> isolates, one multidrug resistant strain was isolated from the urine of a hospitalized woman. This strain was examined to assess its ability to produce carbapenemase enzyme; it produced a colony with a blue metallic color on the CHROMagar KPC chromogenic culture media. In addition, the <i>bla</i><sub>KPC</sub> gene was confirmed by PCR. After sequencing, it was confirmed and deposited in GenBank.<br/><b>Conclusion</b><br/>
To date, many cases of KPC-producing Enterobacteriaceae, in particular <i>K. pneumoniae</i>, have been reported in different countries; there are also some reports on the identification of KPC-producing <i>K. oxytoca</i>. Therefore, to prevent the outbreak of nosocomial infections, the early detection, control, and prevention of the spread of these strains are of great importance.
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