Frequency of Listeria monocytogenes Isolated from Diarrhea Samples of Pediatric Patients at Central Iran.

BACKGROUND: Listeria monocytogenes is a primarily foodborne bacterial pathogen that is one of the causative agents of gastroenteritis. However, the prevalence of L. monocytogenes infection in pediatric patients with diarrheal disease is not clearly identified in the Iranian population. This study aimed to investigate the frequency of L. monocytogenes isolates found in infectious diarrhea samples of pediatric patients in an Iranian population. METHODS: A total of 173 infectious diarrhea samples collected from pediatric patients were used in this crosssectional study. Samples were collected from patients referred to the Children's Educational-Therapeutic Center affiliated with the Arak University of Medical Sciences in Arak, Iran from May-September 2015. To identify the presence of L. monocytogenes, the samples were directly inoculated into the Listeria Enrichment Broth Base through cold enrichment, then plated onto isolated exclusive Listeria Selective Agar Base. As an alternative method for identifying L, monocytogenes, Polymerase Chain Reaction (PCR) of the InlA gene was used. RESULTS: Of the 173 infectious diarrhea samples, eight (4.6%) with L. monocytogenes were identified using exclusive culture media, while nine (5.2%) were identified using PCR. The majority of L. monocytogenes infections (seven cases (77.7%)) were observed in children under the age of five. CONCLUSION: Our results show L. monocytogenes infections to have a low prevalence for causing diarrhea in children in the central region of Iran. This should be taken into consideration by pediatricians when treating intestinal diseases.

Serum Proteomic Profiling of Obsessive-Compulsive Disorder, Washing Subtype: A Preliminary Study.

INTRODUCTION: Obsessive-Compulsive Disorder (OCD) is a disabling mental condition that its proteomic profiling is not yet investigated. Proteomics is a valuable tool to discover biomarker approaches. It can be helpful to detect protein expression changes in complex disorders such as OCD. METHODS: Here, by the application of 2D gel electrophoresis (2DE), a pilot study of serum proteome profile of females with washing subtype of OCD was performed. Serum samples were obtained from females with washing subtype of OCD. Following the protein extraction from the serum with acetone perception, the samples were subjected to 2DE for separation based on pI and molecular weight (MW) with triple replications. Finally, the protein spots were visualized using Coomassie blue staining method and analyzed by Progenesis SameSpots software. Furthermore, protein-protein interaction (PPI) network analysis was handled by the application of Cytoscape software. RESULTS: The results suggested that 41 matched spots demonstrated significant expression alterations among which 5 proteins including immunoglobulin heavy constant alpha-1 (IGHA1), apolipoprotein A-4 (APOA4), haptoglobin (HP), protein α-1-antitrypsin (SERPINA1), and component 3 (C3) were identified by database query. Additionally, PPI network analysis indicated the central role of SERPINA1 and C3 in the network integrity. However, albumin (ALB), amyloid precursor protein (APP), and protein α-1-antitrypsin (APOA1) proteins were important in OCD PPI network as well. The identified proteins were related to 3 processes: acute-phase response, hydrogen peroxide catabolic process, and regulation of triglyceride metabolic process. CONCLUSION: It was concluded that these proteins may have a fundamental role in OCD pathogenesis. Moreover, the dysregulation of inflammatory and antioxidant systems in OCD risk was suggested by the current study. However, evaluation of bigger sample sizes and application of mass spectrometry are essential requirements to confirm this preliminary evaluation.

Frequency of Antiseptic Resistance Among Staphylococcus aureus and Coagulase-Negative Staphylococci Isolated From a University Hospital in Central Iran.

OBJECTIVES: Reduced biocide susceptibility in Staphylococci is associated with various antiseptic resistance genes encoding efflux systems. Our aim was to determine the susceptibility to three disinfectant agents, including benzalkonium chloride (BAC), benzethonium chloride (BZT), and chlorhexidine digluconate (CHDG) among clinical isolates of Staphylococcus aureus and coagulase-negative Staphylococci (CoNS). METHODS: The minimum inhibitory concentration (MIC) of 60 methicillin-resistant S. aureus (MRSA), 54 methicillin-sensitive S. aureus (MSSA) and 51 CoNS isolates from a single hospital to three biocidal agents (BAC, BZT, and CHDG) was determined. Biocide resistance genes (qacA/B, smr, qacG, qacH, qacJ, and norA) were analyzed by the polymerase chain reaction assay. RESULTS: All isolates had MICs for BAC and BZT from 0.25 to 8 µg/mL, and for CHDG from 0.5 to 64 µg/mL. qacA/B was the most common biocide resistance gene among all 165 Staphylococcus isolates (76; 46%), which comprised 38 (63.3%) MRSA, 14 (25.9%) MSSA, and 24 (47%) CoNS. Eleven (6.7%) and 24 (14.5%) isolates among the 165 Staphylococci carried smr and norA genes, respectively. In contrast, other resistance genes such as qacG, qacH, and qacJ were absent in all Staphylococci studied. The qacA/B and smr genes were detected concomitantly in 3% of isolates, and 23.6% strains of the total 165 Staphylococcus isolates were negative for each studied gene. CONCLUSIONS: The carriage of several biocide resistance genes, including qacA/B, smr, and norA, alone or concurrently, is associated with reduced susceptibility. Use of antiseptics may select for antibiotic-resistant strains and assist their survival in the healthcare environment.

The Dynamic of Staphylococcus aureus Nasal Carriage in Central Iran.

BACKGROUND: Nasal carriage of Staphylococcus aureus plays an important role in the pathogenesis of staphylococcal infections. Anterior nasal region is a primary origin of S. aureus. In longitudinal studies, three types of S. aureus nasal carriers can be distinguished: persistent carriers, intermittent or transient carriers, and noncarriers. OBJECTIVES: This study was designed to determine the dynamic of S. aureus nasal carriage in healthy carriers of central Iran. PATIENTS AND METHODS: A total of 813 healthy adults were subjected to this cross-sectional study from November 2011 to January 2012 in Arak University of Medical Sciences. Two anterior nasal swabs were taken with a week interval from each participant. All the isolates were identified as S. aureus phenotypically by standard laboratory methods. The isolates were reconfirmed by amplification of sa442 gene as the identification marker. All the isolates were screened for the presence of the PVL (Panton-Valentine leukocidin) virulence genes and arginine catabolic mobile element (ACME-arc). RESULTS: Among the 813 subjects screened, 83 (10.2%) were persistent carriers, 86 (10.6%) were transient carriers and 644 (79.2%) cases were found as noncarriers. A total of 169 (20.8%) participants had colonized S. aureus. The frequency of ACME-arc A and PVL genes in S. aureus strains were 17% and 20%, respectively. CONCLUSIONS: Carriage of PVL-positive S. aureus is common in this region, even in the low frequency of MRSA colonization. The detection of ACME-arcA gene in S. aureus isolates is a public-health concern and demands continued surveillance and close monitoring.

Is CD19 an immunological diagnostic marker for acute appendicitis?

BACKGROUND: The appendix is considered as part of the gut-associated lymphoid tissue; however, lymphocyte subsets in this tissue are not fully defined. OBJECTIVE: To investigate and compare the function and phenotype of lymphocyte subsets in peripheral blood and appendix of patients with normal and inflamed appendix tissues. METHODS: Peripheral blood samples and appendiceal mononuclear cells were obtained from 81 patients (mean age; 23 ± 10.5 years), clinically suspected of having appendicitis. The phenotypic characteristics of lymphocyte subsets in peripheral blood (before and 48-72 hrs after appendectomy) and in appendix tissue were analyzed by three color-flow cytometry. The proliferative response of mononuclear cells was assessed by MTT method. RESULTS: The frequency of CD19+DR+, HLA-DR+ and CD19+ cells in the appendix tissue were significantly higher than that of the peripheral blood in all the groups (p<0.001). The percentage of CD19+ cells and HLA-DR+CD19+ cells significantly decreased after appendectomy in the peripheral blood of the patients with acute appendicitis (p=0.047 and p=0.03, respectively). CD19 and HLA-DR plus CD19 had better diagnostic efficiency compared with T cell markers (area under the ROC curve [AUC]= 0.76 and 0.73, respectively). CONCLUSION: These results indicate a significant difference in CD19+ and HLA-DR+ lymphocytes between peripheral blood and the appendix tissue.

Short repeats in the spa gene of Staphylococcus aureus are prone to nonsense mutations: stop codons can be found in strains isolated from patients with generalized infection.

Fifteen sequences with stop codons have been obtained in the course of standard methicillin-resistant Staphylococcus aureus (MRSA) spa typing. In nine of those sequences, stop codons occurred due to nonsense G-T and A-T transversions. G-T transversions would appear to be frequent in the spa gene, mostly due to symmetric mutational AT-pressure in the whole S. aureus genome and due to replication-associated mutational pressure characteristic of lagging strands of the "chromosome". A-T transversions would appear to be frequent in the spa gene mostly due to transcription-associated mutational pressure. Relative to other S. aureus genes, short repeats in spa are enriched by nonsense sites for G-T and A-T transversions; the probability of being nonsense for A-T transversion is high in that part of spa coding region. 13 out of 15 (87%) of the sequences with stop codons were obtained from strains isolated from patients with generalized S. aureus infection. Truncation of spa at its C-terminus is predicted to result in a protein that possesses functional IgG binding domains unable to be linked to the cell wall. This is discussed in light of the known fact that extracellular spa is a strong virulence factor involved in immune evasion.