Multidrug-resistant Salmonella strains from food animals as a potential source for human infection in Iran.

This study aimed to determine the frequency and characterization of Salmonella isolates from food-producing animals and human diarrheal samples in Shiraz, Iran. Overall, 105 Salmonella isolates were obtained from chicken meat (70/100, 70.0%), beef (19/100, 19.0%), lamb (11/100, 11.0%), and human stool (5/295, 1.7%). S. Infantis (40.9%), S. Enteritidis (29.5%), and S. Paratyphi B (8.6%) were the most prevalent serotypes. Totally 59.1% of the isolates were multidrug-resistant. High resistance to nalidixic acid (67.6%), tetracycline (62.9%), and trimethoprim-sulfamethoxazole (42.3%) were observed. Mutations in the gyrA and parC genes were detected in nalidixic acid-resistant isolates from chicken meat and human stool. No qnrA, qnrB or qnrS genes were detected. The blaTEM and blaCMY-2 genes were detected in ß-lactam-resistant isolates from beef and lamb. Despite the high genetic diversity of PFGE patterns, some isolates from different sources and times showed identical PFGE patterns suggesting specific Salmonella species circulate between various sources over time.

Survey of Salmonella in commercial broiler farms in Shiraz, southern Iran.

Salmonella is one of the major causes of food-borne diseases, worldwide. The aim of the present study was to describe the prevalence of Salmonella and to employ a polymerase chain reaction (PCR) assay to confirm the presence of Salmonella Enteritidis and Salmonella Typhimurium in the broiler chicken farms in Shiraz, southern Iran. In addition, risk factors for the presence of Salmonella spp. at farm and flock levels were investigated. Fecal samples were collected from 22 broiler farms, including 35 broiler flocks. Conventional culture methods were used for Salmonella isolation, and the suspected isolates were confirmed by PCR with Salmonella specific primer (invA). Subsequently, PCR was performed to identify S. Enteritidis and S. Typhimurium, using IE-1 and Flic-C primers, respectively. Information for farms and flocks was collected using a questionnaire. Twelve poultry flocks from eight farms were positive for Salmonella. The estimated prevalence of Salmonella was 36.4% at farm level and 34.3% at flock level. Based on the results of PCR, four farms were infected with S. Enteritidis, two farms with S. Typhimurium and one farm with both serovars, concurrently. Statistical analysis using generalized estimating equations showed that at flock level, odds of Salmonella presence increased when the number of chickens was more than 15000 (OR = 13.2, P = 0.023), and an increased odds of Salmonella was found for flocks in which antibiotics were used at sub-therapeutic or therapeutic doses during the rearing period (OR = 19.6, P = 0.003). At the farm level, there was a marginal association between Salmonella and using nipple drinker (OR = 0.08, P = 0.07) and keeping dogs on the farm (OR = 8.9, P = 0.06) by logistic regression analysis. In conclusion, Salmonella spp. including S. Enteritidis and S. Typhimurium are prevalent in the poultry flocks in the region. Considering the results and the fact that the flock size and its surrogate marker, stocking density are among the most consistently identified risk factors for Salmonella in the literature, production cycles with the appropriate number of chicks and proper stocking density are recommended. In addition, careful monitoring and prudent use of antibiotics in poultry farms could be practiced to control this human pathogen in preharvest poultry operations.

Preparation of Immunotoxin Herceptin-Botulinum and Killing Effects on Two Breast Cancer Cell Lines.

BACKGROUND: Worldwide, breast cancer is the most common cancer diagnosed among women and a leading cause of cancer deaths. The age of onset in Iran has become reduced by a decade for unknown reasons. Herceptin, a humanized monoclonal antibody, is a target therapy for breast cancer cells with over expression of HER2- neu receptors, but it is an expensive drug with only 20% beneficial rate of survival. This study introduces a novel approach to enhance the efficacy of this drug through immunoconjugation of the antibody to botulinum toxin. Decreasing the cost and adverse effects of the antibody were secondary goals of this study. MATERIALS AND METHODS: Botulinum toxin was conjugated with Herceptin using heterobifunctional cross linkers, succinimidyl acetylthiopropionate (SATP) and sulfo-succinimidyl-4-(N-maleimidomethyl) cyclohexane-1-carboxylate (SMCC) according to the supplier's guidelines and tested on two breast cancer cell lines: SK-BR-3 and BT-474. Toxin and Herceptin were also used separately as controls. The cytotoxicity assay was also performed using the new bioconjugate on cultured cells with Alamar blue and a fluorescence plate reader. RESULTS: Herceptin-Toxin bioconjugation significantly improved Herceptin efficacy on both breast cancer cell lines when compared to the control group. CONCLUSIONS: Toxin-Herceptin bioconjugation can be a potential candidate with increased efficiency for treating breast cancer patients with over expression of the HER2 receptor.