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Background and purpose: Giardia cyst and trophozoite have invariant morphologies, therefore, investigating aspects such as host specificity, transmission patterns and clinical behavior of the parasite in hosts requires molecular characterization of the parasites isolated from clinical samples. The aim of this study was to characterize giardiasis isolated from human fecal samples with symptomatic (with a history of chronic diarrhea) and asymptomatic giardiasis and investigating the correlation of parasite's assemblage with diarrhea. Materials and methods: Thirty one fecal samples containing Giardia cysts from individuals with symptomatic and asymptomatic giardiasis were used to characterize the parasites' genotype. Triose Phosphate Isomerase (TPI) gene was amplified by polymerase chain Reaction (PCR). Demographic information was recorded using a questionnaire and SPSS ver.16 and Fisher’s exact test were applied to analyse the data. Results: PCR showed a higher frequency of Giardia duodenalis assemblage B compared with assemblage A (51.6% vs. 35.5%). However, the frequency of Giardia duodenalis assemblage A in symptomatic giardiasis was significantly higher than that of the asymptomatic giardiasis (62.5% vs. 18.75%). The Fisher's exact test revealed a significant correlation between Giardia doudenalis assemblage A and diarrhea (p<0.005). Conclusion: Usually, duodenalis assemblage A is accompanied by clinical symptoms such as diarrhea. However, duodenalis assemblage B is more prevalent among those with diarrhea.

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Background and purpose: Clostridium difficile is an obligate anaerobic, gram positive bacillus. The purpose of this study was to develop and optimize Loop-mediated Isothermal Amplification (LAMP) technique for assessing the prevalence of Clostridium difficile infection in the samples of watery diarrhea. Material and methods: This cross-sectional qualitative study was performed in 48 samples of watery diarrhea (fecal samples were obtained from 24 patients with nosocomial diarrhea and 24 patients with antibiotic-associated diarrhea). All samples were cultured in the specialized CDMN Agar medium. Six specific primers were applied for the LAMP Assay and the LAMP reaction was conducted under optimal conditions. Furthermore, sensitivity and specificity of LAMP were determined to detect Clostridium difficile. Results: In this study, the optimized LAMP technique was determined to be 10 bacterium. In addition, LAMP technique showed a high specificity for detecting the bacteria. Among the patients with nosocomial diarrhea and antibiotic-associated diarrhea, 18.2% and11.5% were reported to be positive, respectively. Conclusion: LAMP was found as an applicable, sensitive, and quick technique for detection of Clostridium difficile.

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Background and purpose: Oral Rehydration Therapy (ORT) is recommended in cases of mild to moderate dehydration for better treatment of acute diarrhea in children. This study aimed at assessing the knowledge and attitudes of physicians working in health centers and emergency departments in Mazandaran province about ORT in children with acute diarrhea.

Materials and methods: In a cross-sectional study, in 2014-2015, 258 physicians were randomly selected from Mazandaran province. Relevant information were collected including the method/s for evaluation of patients, management of complications, and adherence to national protocol and the protocol of World Health Organization (WHO).

Results: In our study 27.6% of the participants had attended courses on ORT and their information about treatment of diarrhea was significantly higher than that of other doctors who did not pass similar courses (P= 0.009). More than 50% of physicians had appropriate information about ORT and administration of ORS, antibiotic therapy, and home treatment of dehydration. But more than 50% of physicians did not have enough information about the new protocol of ORT. The most common reasons for not using ORT was faster response to IV therapy and lack of acceptance of ORT by families.

Conclusion: In this study, only about one-third of the physicians attended courses on ORS, therefore, more attention and planning is needed for participation of physicians in this courses.

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Background and purpose: The medlar (Mespilus germanica L., Rosaceae) is an edible fruit and modern medicine has recognized its healing properties in treatment of some diseases. There is no scientific data in literature about its activity against some bacteria. In this study, antibacterial activity of hydro-acetonic extract of medlar¢s leaf was evaluated against some bacteria.

Materials and methods: In this experimental study, the leaves were collected from Sari, Iran. Materials were dried at room temperature and coarsely ground before extraction. The extraction was performed at room temperature by maceration method using acetone (70%) as solvent. Total phenols and tannins were determined by Folin-ciocalteu method and antibacterial effects were studied. Minimal Inhibitory Concentration (MIC) and Minimal Bactricidal Concentration (MBC) were calculated by Broth Dilution Test.

Results: The yield of extraction was 20%. Total phenolic and tannins contents were 90±10 GAE (based on standard curve) and 10±4 /g extract, respectively. The extract showed best inhibitory and bactericidal activities against Klebsiella pneumoniae (MIC= 3.333 ± 0.0233 and MBC= 5.833 ± 0.065). The lowest MIC was observed against Vibrio Cholera (6.667±0.048) and the lowest MBC was seen against E. coli and Shigella dysentiea (9.167±0.042).

Conclusion: M. germanica leaf extract showed good antibacterial activities. So, this plant is potentially effective in controlling dysentery.

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Background: Diarrhea with salmonella and shigella infections is one of the main causes of mortality in children less than 5 years. Determining the antibiotic resistance of these bacteria is one of the most important methods in the treatment of diarrhea. This study was performed to evaluate antibiotic resistance of Salmonella and Shigella pathogenic bacteria in children with acute diarrhea referred to Amirkola Childrenchr('39')s Hospital.
Methods: This cross-sectional study was performed on 252 stool samples collected from children aged 6 months to 5 years with acute diarrhea referred to Amirkola Hospital in 2018. Samples were cultured and the bacteria were isolated by routine methods and the identified strains were evaluated for antibiotic resistance and abundance of class I, II and III integron genes.
Results: Out of 252 samples, 15(5.9%) were positive for Shigella spp and 13 (5.1%) were positive for Salmonella. Antibiotic resistance of Shigella and Salmonella for nalidixic acid(100%) and(54%),trimethoprim sulfamethoxazole(93%) and (0%), azithromycin (87%) and (23%), ampicillin, respectively. Ampicillin(73%) and (8%), cefotaxime (60%) and (46.1%) were observed.
Of the 15 Shigella strains, all were ESBL positive (beta-lactamase positive). In Salmonella, 7 strains (53.9%) were ESBL positive. PCR results showed that 11 (73.3%), 14 (93%) and 10 (66.7%) of Shigella isolates carried intl I,II and both intlI/intlII genes. Class III integron not detected. PCR results revealed that 23% (3/13) of Salmonella isolates carried intl I, no class II,III integrons were detected.
Conclusion: The results showed that the frequency of Shigella infection and also their antibiotic resistance is higher than Salmonella.