Serogroups, and drug resistance of nontyphoidal Salmonella in symptomatic patients with community-acquired diarrhea and chicken meat samples in Tehran.

BACKGROUND: Salmonella is considered as a main cause of community-acquired diarrhea in humans, however, sources of the multi-drug resistant (MDR) strains and their link with the disease are not well known. AIMS: This study aimed to investigate the frequency, serogroup diversity, and antimicrobial susceptibility patterns of Salmonella strains in poultry meat and stool samples of patients with community acquired diarrhea in Tehran. METHODS: We compared the frequency of non-typhoidal Salmonella serogroups, the similarities of their resistance patterns to 10 antimicrobial compounds, the prevalence of extended spectrum ß-lactamase (ESBL) and ampicillinase C (AmpC) genetic determinants, and class 1 and 2 integrons in 100 chicken meat and 400 stool samples of symptomatic patients in Tehran during June 2018 to March 2019. RESULTS: Salmonella was isolated from 75% and 5.5% of the chicken meats and human stool samples, respectively. The chicken meat isolates mainly belonged to serogroup C (88%, 66/75), while the human stool isolates were mainly related to serogroup D (59.1%, 13/22). The MDR phenotype and the most common rates of resistance to antibiotics, including tetracycline, trimethoprim/sulfamethoxazole (TS) and azithromycin, were detected in 4.5% and 45.3%, 59% and 13.6%, 43% and 9.1%, 42% and 9.1% of the human stool and chicken meat samples, respectively. Carriage of bla CTX, bla SHV, and bla PER genes in the meat isolate with ESBL resistance phenotype and bla ACC, bla FOX, and bla CMY-2 among the 7 meat strains with AmpC resistance phenotype was not confirmed using polymerase chain reaction (PCR). High prevalence of class 1 and 2 integrons was characterized and showed a correlation with resistance to TS and chloramphenicol. CONCLUSION: These findings showed a lack of association between chicken meats and human isolates due to discrepancy between the characterized serogroups and resistance phenotypes.

Importance of Listeria monocytogenes in food safety: a review of its prevalence, detection, and antibiotic resistance.

Listeria monocytogenes, as a foodborne pathogenic bacterium, is considered as major causative agent responsible for serious diseases in both humans and animals. Milk and dairy products are among the main sources of energy supply in the human, therefore contamination of these products with Listeria spp., especially L. monocytogenes, could lead to life threatening infections in a large population of people. Rapid and accurate detection of L. monocytogenes in milk and dairy products, vegetables, meat, poultry, and seafood products is needed to prevent its dissemination through the food chain. Upon contamination of food materials with this pathogen, increase in its antibiotic resistance rate can occur after exposure to preservatives, antibiotics, and stress conditions, which has now become another major public health concern emphasizing the need for special attention on its control along the food chain and management of the disease in the patients. This review provides an overview of researches with respect to the prevalence of Listeria spp., especially L. monocytogenes, in milk and dairy products, methods of their detection and typing, and current status of resistance rates to the antibiotics used for treatment of listeriosis.

Infectious etiology of chronic diarrhea in patients with primary immunodeficiency diseases.

Summary: Background.Primary immunodeficiency diseases (PIDs) are life-threatening disorders, which manifest commonly with gastrointestinal (GI) signs, mainly as chronic diarrhea. Objective. To investigate and compare infectious etiology of chronic diarrhea in different PIDs. Patients and methods. Assessing clinical features, obtaining immunological profiles, as well as characterizing infectious etiology of diarrhea were performed in 38 PID patients with chronic diarrhea. Stool samples and/or biopsy specimens were checked using culture, microscopic examination, RT-PCR, and PCR, as appropriate. The patients were diagnosed to have common variable immunodeficiency (CVID), severe combined immunodeficiency (SCID), X-linked agammaglobulinemia (XLA), and hyper-IgM (HIgM) syndrome. Results. In 32 patients we identified 41 infectious agents including 16 parasitic (39.0%, the most common Giardia lamblia), 11 bacterial (26.8%, the most common salmonella spp), 8 viral (19.5%, the most frequent group A rotavirus), and 6 fungal organisms (14.7%, the most common Candida albicans). From 6 of the patients, no infectious agent was isolated. In CVID bacteria and parasites, in SCID bacteria and viruses, in XLA parasites, and in individuals with HIgM syndrome parasites were the leading causes of chronic diarrhea. Infection with giardia and cryptosporidium were more frequent in XLA and HIgM, respectively. Conclusion. The current study suggests considering both usual and unusual pathogens in laboratory investigation and in the empiric treatment of chronic diarrhea. Opportunistic pathogens should be taken into account when no other pathogen is identified, especially in patients on long-term treatment or prophylaxis with antifungals/antibiotics and in those from geographical locations that favor pathogenicity of these organisms.

Association of diverse bacterial communities in human bile samples with biliary tract disorders: a survey using culture and polymerase chain reaction-denaturing gradient gel electrophoresis methods.

Bacterial infection is considered a predisposing factor for disorders of the biliary tract. This study aimed to determine the diversity of bacterial communities in bile samples and their involvement in the occurrence of biliary tract diseases. A total of 102 bile samples were collected during endoscopic retrograde cholangiopancreatography (ERCP). Characterization of bacteria was done using culture and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) methods. Antimicrobial susceptibility of the isolates was determined based on the Clinical and Laboratory Standards Institute (CLSI) guidelines and identity of the nucleotide sequences of differentiated bands from the DGGE gels was determined based on GenBank data. In total, 41.2 % (42/102) of the patients showed bacterial infection in their bile samples. This infection was detected in 21 % (4/19), 45.4 % (5/11), 53.5 % (15/28), and 54.5 % (24/44) of patients with common bile duct stone, microlithiasis, malignancy, and gallbladder stone, respectively. Escherichia coli showed a significant association with gallstones. Polymicrobial infection was detected in 48 % of the patients. While results of the culture method established coexistence of biofilm-forming bacteria (Pseudomonas aeruginosa, E. coli, Klebsiella pneumoniae, Enterococcus spp., and Acinetobacter spp.) in different combinations, the presence of Capnocytophaga spp., Lactococcus spp., Bacillus spp., Staphylococcus haemolyticus, Enterobacter or Citrobacter spp., Morganella spp., Salmonella spp., and Helicobacter pylori was also characterized in these samples by the PCR-DGGE method. Multidrug resistance phenotypes (87.5 %) and resistance to third- and fourth-generation cephalosporins and quinolones were common in these strains, which could evolve through their selection by bile components. Ability for biofilm formation seems to be a need for polymicrobial infection in this organ.

Association of CagPAI integrity with severeness of Helicobacter pylori infection in patients with gastritis.

BACKGROUND AND AIM: The Helicobacter pylori cag pathogenicity island (cagPAI) is involved in delivery of CagA effector protein and peptidoglycan into host cells and also in IL-8 induction in the human gastric tissue. Diversity of cagPAI may affect disease status and clinical outcome of the infected patients. Our study was aimed to investigate diversity of this island and its intactness in Iranian patients to investigate possible associations between cagPAI integrity and pathological changes of the infected tissue. MATERIAL/PATIENTS AND METHODS: Out of the 75 patients, H. pylori strains were obtained from 30 patients with severe active gastritis (SAG) (n=11), moderate chronic gastritis (CG) (n=14) and intestinal metaplasia/dysplasia (IM) (n=5). Intactness of the cagPAI was determined using 12 sets of primer pairs specific for functionally important loci of cagPAI by polymerase chain reaction (PCR). RESULTS: The cagPAI positive strains were significantly observed in patients with SAG (52.4%) in comparison to those presenting CG (33.3%) and IM (14.3%). In addition, the presence of intact cagPAI was 87.5% in H. pylori strains isolated from patients with SAG, which was higher than those obtained from patients with CG (12.5%) or IM (0%). A significant increase in the frequency of cagα-cagY and cagW-cagT segments, as exterior proteins of the CagPAI, was illustrated in strains from SAG patients compared with those from patients with CG. CONCLUSIONS: Overall, these results strongly proposed an association between the severity of histopathological changes and intactness of cagPAI in the gastric tissue of patients infected with H. pylori.

Gene disruption in Salmonella typhimurim by modified λ Red disruption system.

There are many techniques to knock out directed genes in bacteria, some of which have been described in Salmonella species. In this study, a combination of SOEing PCR method and the λ Red disruption system were used to disrupt phoP gene in wild type and standard strains of Salmonella typhimurium. Three standards PCR and one fusion PCR reactions were performed to construct a linear DNA including upstream and downstream of phoP gene and Kanamycin cassette. As a template plasmid, we used pKD4 which carries kanamycin gene flanked by FRT (FLP recognition target) sites. The resulting construct was electroporated into prepared competent cells of S. typhimurium. The transformants colonies related to the standard strain appeared on the LB-Km-agar plates after incubation, but there was no colony on LB-Km-agar plates corresponding to the wild type strain. The failure in transformation of the wild type strain may be because of inflexibility of the λ Red disruption system in this strain or its unique restriction-modification system. However, by this construct we are able to generate phoP mutant in many of the Salmonella species due to high homology of the phoP gene which exists in different species.

Antimicrobial susceptibility patterns of the gram-negative bacteria isolated from septicemia in Children's Medical Center, Tehran, Iran.

INTRODUCTION: The choice of antimicrobial treatment for septicemia is often empirical and based on the knowledge of local anti-microbial activity patterns of the most common bacteria causing such bloodstream infections. The current study aimed to study the prevalence of bacterial pathogens causing septicemia and their antimicrobial resistant profiles in hospital admitted patients. METHODS: This cross sectional study done at Children's Medical Center, Tehran, Iran. We examined 168 bacterial strains isolated from 186 clinically diagnosed septicemia cases refereed at Children's Medical Center, Tehran, Iran. Over a period of twelve months from July 2010 to 2011 July. 11446 blood samples from patients of clinically suggestive septicemia were evaluated. RESULTS: Bacterial strains were isolated from 910 (7.95%) of blood cultures. Gram-negative bacteria identified were Pseudomonas species (20.5%), Pseudomonas aeruginosa (1.86%), Salmonella spp (1.09%), Acinetobacter naumannii (8.13%), Escherichia coli (4.06%), Klebsiella spp (5.16%). Gram-negative pathogens were more than gram positive in bloodstream infections. Antimicrobial susceptibility testing was done according to Clinical and Laboratory Standards Institute (CLSI, USA) guidelines against: amikacin ampicillin, amoxicillin, amoxiclav, cefuroxime, cefotaxime, ceftazidime, cefoperazone tetracycline, chloramphenicol, ciprofloxacin, gentamicin. Resistanc to different antibiotics in the most important isolated bacteria were: 32.1%, 10.8%, 87.8%, 96%, 39.1%, 35.2, 49.4%, 69%, 80.02%, 22%, 59%, 30.1% respectively, for Pseudomonas spp, 32%, 3.7%, 84.2%, 83.2%, 80.1%, 75.4%, 44.8%, 45.2%, 33.3%, 19%, 34.1, 11.5% respectively for Acinetobacter species. DISCUSSION: Resistant to majority of the antimicrobial agents for several pathogens implicated in bloodstream infections, particularly in Gram-negative bacteria, can make complication in treatment of infection cause by them.

Genetic variability of Blastocystis sp. isolated from symptomatic and asymptomatic individuals in Iran.

Blastocystis is an unusual enteric protozoan parasite of humans and many animals whose pathogenic potential is still controversial. To increase the understanding of the molecular epidemiology of this emerging parasite and due to its potential impact on public health, its subtypes (STs) in Iranian symptomatic and asymptomatic individuals were determined. A total of 100 Blastocystis isolates by microscopy and culture methods were obtained. DNA was extracted from the positive culture isolates, and the Blastocystis subtypes were identified using seven subtype-specific sequenced-tagged site (STS) primers. Four subtypes, ST3 as dominant (53 %), followed by ST1 (48 %), ST5 (33 %), and ST2 (7 %) were identified. In this study, ST1 in gastrointestinal patients compared to asymptomatic individuals was significantly dominant (p = 0.001). From 33 (33 %) mixed subtype infections, ST1, 3 (14 %) was significantly related to GI symptoms (p = 0.045), and eight mixed infections with three different STs, which are under reported, were also identified.

Distribution of class 1 integrons among enteropathogenic Escherichia coli.

The aim of this study was to investigate the incidence of and resistance gene content of class 1 integrons among enteropathogenic Escherichia coli (EPEC) and non-EPEC and to investigate intraspecies genetic diversity of EPEC strains isolated from children with diarrhea in Iran. Twenty-eight EPEC and 16 non-EPEC strains isolated from children with diarrhea were tested for the presence of a class 1 integron associated integrase gene (int1). Sequence analysis was performed to identify the resistance gene content of integrons. Genetic diversity and cluster analysis of EPEC isolates were also investigated using enterobacterial repetitive intergenic concensus-polymerase chain reaction (ERIC-PCR) fingerprinting. Twenty-three (82%) EPEC isolates and 11 (68.7%) non-EPEC isolates harbored the int1 gene specific to the conserved integrase region of class 1 integrons. Sequence analysis revealed the dominance of dfrA and aadA gene cassettes among the isolates of both groups. ERIC-PCR fingerprinting of EPEC isolates revealed a high diversity among these isolates. The widespread distribution of 2 resistance gene families (dfrA and aadA) among both groups of EPEC and non-EPEC isolates indicates the significance of integrons in antibiotic resistance transfer among these bacteria. Furthermore, clonal diversity of EPEC isolates harbouring a class 1 integron also suggests the circulation of these mobile elements among a diverse population of EPEC in this country.

Molecular epidemiology of cryptosporidiosis in Iranian children, tehran, iran.

BACKGROUND: Cryptosporidium is a worldwide protozoan parasite and one of the most common causes of infection and diarrhea in humans and cattle. The aim of the present study was determination of subtypes of Cryptosporidium among children with diarrhea in Tehran by sequence analysis of the highly polymorphic 60-kDa glycoprotein (GP60) gene. METHODS: Fecal samples were collected from 794 diarrheic children. Initial identification of Cryptosporidium was carried out on stool samples by Ziehl-Neelsen acid-fast staining method. DNA was extracted from positive microscopically samples and Cryptosporidium genotypes and subtypes were determined, accordingly. RESULTS: Out of 794 collected samples, 19 (2.40%) were positive for Cryptosporidium oocysts. Sequences analysis of GP60 gene showed that 17 (89.47%) of the positive isolates were Cryptosporidium parvum and 2 (10.52%) were C. hominis. All subtypes of C. parvum isolates belonged to allele families IIa (6/17) and IId (11/17). The most common allele in all 17 isolates belonged to IId A20G1a (41.18%). A22G1 (IF) subtype was detected in two C. hominis isolates of the children. CONCLUSION: The predominancy of C. parvum species (specially, IId A20G1a subtype) in current study underlines the importance of zoonotic Cryptosporidium transmission in Iran.

Fatal sepsis by Bacillus circulans in an immunocompromised patient.

An immunosuppressed man was admitted to hospital with diarrhea and a history of urinary tract infection. He was subjected to treatment with antibiotics. The patient died of putative severe sepsis. The etiological agent was a carbapenemase producing isolate of Bacillus circulans with resistance to all prescribed antimicrobial agents.

Hodgkin lymphoma as second malignancy during continuing chemotherapy for childhood acute lymphoblastic leukemia.

Acute lymphoblastic leukemia (ALL) is the most prevalent childhood malignancy in most parts of the world with a 5-year survival rate above 70%. Long-term survivors are at risk for treatment-related late effects and second malignant neoplasms (SMNs). SMNs occur with a mean latency of 6-6.7 years after ALL diagnosis but are rarely observed during maintenance chemotherapy (CT). Hodgkin lymphoma (HL) as a complication of ALL is very rare. We report two children with ALL who developed HL while receiving maintenance CT. Both received appropriate chemo- and radiotherapy (CT/RT) and have survived for more than10 years.

Bone mineral density in Iranian adolescents and young adults with beta-thalassemia major.

The authors investigated the prevalence of low bone mass in patients from Tehran, Iran, with beta-thalassemia major (n = 203), aged 10-20 years, and the potential risk factors for osteoporosis in this patient population. Prevalence of osteoporosis was 50.7% in lumbar spine, 10.8% in femur, and 7.9% in both regions with no significant difference between the two genders. The following factors were associated with low BMD: height for age and weight for age below 3rd percentile, delayed puberty or hypogonadism, age when Desferal (for iron chelation) was started, duration of Desferal therapy, and serum zinc. Low serum copper and 25(OH)D were not associated with low BMD.

Successful ambulatory treatment of Hodgkin's disease in Iranian children based on German-Austrian DAL-HD 85-90: single institutional results.

BACKGROUND: Hodgkin's disease (HD) accounts for 7.5% of childhood malignancies in Iran. In order to minimize chemotherapy toxicity and avoid eventual hospitalization and psychological and financial burdens we have applied since 1988, for the first time in Iran, a treatment regimen based on subsequently revised DAL-HD 85-90 and later GPOH-HD 95 protocols. PATIENTS AND METHODS: During the period 1988-2004, 40 children with HD received DAL/GPOH-HD-adapted treatment; 25 males (62.5%) and 15 females (37.5%) (male/female ratio 1.7; age 4-14 years, mean 8.8). Clinical evaluation and staging was performed in all patients. Constitutional symptoms: 24 patients were asymptomatic (A; 60%) and 16 had constitutional complaints (B; 40%). Staging was as follows: stage I; seven (17.5%); II, 11 (27.5%); III, 11 (27.5%); and IV, 11 (27.5%). Histopathology: 22 patients had mixed cellularity (MC; 55%), 13 nodular sclerosis (32.5%), four lymphocyte predominance (LP; 10%) and one patient lymphocyte depletion (2.5%). Stage IA and IIA patients (n = 15) received either OPA x2 (vincristine, prednisolone, doxorubicin) or OPPA x2 or OPEA x2 (vincristine, prednisolone, procarbazine and doxorubicin), the latter receiving etoposide instead of procarbazine, and applied to males. Stages IIB, IIIA/B and IV received OPPA x2, followed by CO(P)P x4 (cyclophosphamide, vincristine, prednisolone in alternate courses and procarbazine). Twenty nine patients (72.5%) received radiotherapy (20-25 Gy); four to the involved field (stage I), 25 to the upper mantel (stage II and also III with either residual or mediastinal mass) and three additionally to spleen and para-aortic lymph nodes. Eleven patients received only chemotherapy. RESULTS: All patients achieved complete remission (CR). Relapse occurred in eight patients (20%); seven stage IV (MC) and one stage IA (LP) with progression to IIIB. Salvage chemotherapy consisted of MOPP/ABVD hybrid; six patients achieved a second sustained remission and three patients died: two due to relapse and progressive disease and the third one in CR, owing to thrombocytopenic hemorrhage and foudroyant pneumonia. The achieved overall and event-free survival was 88.1% and 75.4%, respectively. Aside from minor acute toxicities, three patients demonstrated azoospermia at the age of 18 years and one of these patients suffered non-Hodgkin lymphoma as a second malignancy. HD occurred as a second malignancy in two patients with acute lymphoblastic leukemia. Both received appropriate treatment and are over 10 years in CR. CONCLUSIONS: The DAL/GPOH-HD-based treatment approach proved to achieve long-term sustained cure even in children with advanced HD disease. The essentially outpatient diagnosis and treatment modus did not compromise the disease outcome, and was well tolerated and accepted by the patients and their parents. The employed drugs are easily available and affordable. This treatment approach is suitable for ambulatory use in developing countries. However, male infertility remains the major obstacle to procarbazine and cyclophosphamide use.

Involvement of interleukin-1beta in systemic morphine effects on paw oedema in a mouse model of acute inflammation.

Recent studies suggest that peripheral morphine may represent a valuable treatment in acute inflammatory painful diseases through peripheral or central mechanisms. In the present study, anti-inflammatory effects of systemic morphine on carrageenan-induced hind paw oedema were examined in a model of peripheral acute oedema in mice. Carrageenan induced a time-dependent inflammation that was maximal 3 h after administration. While intraperitoneal administration of morphine sulfate at a low dose (1 mg/kg) increased carrageenan-induced hind paw oedema, intraperitoneal injection of morphine sulfate at a high dose (7 mg/kg) resulted in significant anti-inflammatory effects on carrageenan-induced hind paw oedema. These anti-inflammatory effects were blocked by pretreatment with naloxone. Measuring the serum levels of interleukin-1beta revealed that increases in serum levels of this cytokine were involved in morphine anti-inflammatory effects. Pretreatment with naloxone decreased interleukin-1beta serum levels near to those of control group. In conclusion, these data demonstrate that morphine produced pro- or anti-inflammatory effects in a dose-dependent manner through peripheral or central mechanisms. The observed anti-inflammatory effects may be due to an increase in the cytokine production and/or release by host immune systems.

Hydroxyurea in the treatment of major beta-thalassemia and importance of genetic screening.

Efforts have been undertaken to find an alternative approach to packed red cell transfusion (PRCT) in major beta-thalassemia. Augmentation of fetal hemoglobin (HbF) by hydroxyurea (HU) has been reported to be less effective in this condition as compared to sickle cell anemia due to molecular heterogeneity of the former disease. HU efficacy and its relation to Xmn1 polymorphism and IVSII-1 mutation was evaluated in major beta-thalassemics. Forty-five patients, M/F ratio 0.8, aged 6-33 years, received oral HU, 20 mg/kg per day, 4 days per week and daily1 mg folic acid. Thirty-six patients were PRCT dependent (group A) and nine independent (group B). The aim was to stabilize or increase pre-PRCT Hb over 10.0+/-0.5 g/dl and to reduce the need or cease the PRCT in group A and to increase Hb level and curb the ineffective erythropoesis, e.g., splenomegaly, facial bone deformity, in group B. HU was administered for at least 6 months (mean: 9 months) and discontinued in case of response failure. Screening for Xmn1 polymorphism and IVSII-1 mutation was carried out in most patients. In group A, 25 patients have become PRCT independent for a period of 2.5-7.3 years (mean: 4 years). The mean Hb, pre-HU 10.0 and post-HU 10.7 g/dl (range: 8.8-13.7 g/dl), mean serum ferritin pre- and post-HU was1877 and 525 ng/ml. The PRCT requirement was reduced in one patient, and ten patients did not respond. In group B HU has been given over 3.3 years (range: 2.8-4.8 years), Hb increased from 9.3 to 10.4/dl, and there was no tangible progression of ineffective erythropoesis. Responders in both groups expressed more comfort with this regimen. Xmn1 and IVSII-1 (homo- and/or heterozygosis) are relevant markers in most responding patients. Molecular determination of genetic markers in early childhood will help to identify candidates for pharmacological HbF switching by HU.

Hodgkin disease in Iranian children.

The epidemiological pattern of Hodgkin disease (HD) was studied in 139 Iranian children with an age range of 2.5-15 years (mean age 8.3) over a 17-year period (1972-1989). The main features observed were: a high male to female ratio of 3.2:1, a high frequency of HD in toddlers and young school children (73%), the prevalence of mixed cellularity subtype (74.5%) and rare occurrence of lymphocyte depletion subtype (2%) the high occurrence of constitutional symptoms (57%) and the high rate of stage III and IV patients (73.5%). Response to the treatment consisting mainly of chemotherapy and/or radiotherapy was favourable and overall and disease-free survival rates of 91.4% and 74.2% were achieved over a follow up period of 6 months-17 years. According to these findings the epidemiological pattern of Iranian children with HD is similar to that occurring in rural areas of developed countries.

[Partial splenectomy in homozygous beta-thalassemia]. / Partielle Splenektomie bei homozygoter beta-Thalassämie.

Six children, 2 1/2 to 6 years old, with homozygous beta-thalassemia underwent partial splenectomy as indicated by splenomegaly and high blood transfusion requirement. A marked reduction of blood requirement has been achieved in 2 children with an annual blood transfusion volume up to 150 ml per kg body weight. The other four children required total splenectomy as blood requirement remained high and significant splenomegaly developed within few weeks after the partial splenectomy. The immunological function of the spleen residue remains still controversial and needs further evaluation. Partial splenectomy might be indicated therefore only in selected children with homozygous beta-thalassemia.