Isolation, Molecular Identification, and Antibiotic Resistance Profile of Salmonella Typhimurium Isolated from Calves Fecal Samples Dairy Farms in Hamedan

In order to identify the genetic basis for the attenuation of Salmonella typhimurium LT2 strains, experiments were performed to identify a gene(s) which restores virulence to an avirulent LT2 strain. These and further experiments confirmed that an rpoS mutation is the sole determinant of the attenuation of S. typhimurium LT2.

A chromosomal region present in Salmonella typhimurium but absent from related species was identified by hybridization. A DNA probe originating from 78 min on the S. typhimurium chromosome hybridized with DNA from Salmonella enteritidis, Salmonella heidelberg, and Salmonella dublin but not with DNA from Salmonella typhi, Salmonella arizonae, Escherichia coli, and Shigella serotypes. Cloning and...

Transmission is an essential stage of a pathogen's life cycle and remains poorly understood. We describe here a model in which persistently infected 129X1/SvJ mice provide a natural model of Salmonella enterica serovar Typhimurium transmission. In this model only a subset of the infected mice, termed supershedders, shed high levels (>10(8) CFU/g) of Salmonella serovar Typhimurium in their feces...

The autoinducer-3 (AI-3)/epinephrine (Epi)/norepinephrine (NE) interkingdom signaling system mediates chemical communication between bacteria and their mammalian hosts. The three signals are sensed by the QseC histidine kinase (HK) sensor. Salmonella enterica serovar Typhimurium is a pathogen that uses HKs to sense its environment and regulate virulence. Salmonella serovar Typhimurium invades e...

Foodborne salmonellosis is one of the most important bacterial zoonotic diseases worldwide. Salmonella Typhimurium is the serovar most frequently isolated from slaughter pigs in Europe. Circumvention of the host’s immune system by Salmonella might contribute to persistent infection of pigs. We found that Salmonella Typhimurium strain 112910a, which is able to persist in pigs, was capable of dow...

An fljB-negative, multidrug-resistant Salmonella enterica serovar 4,5,12:i:- phage type DT U302 strain (resistant to ampicillin, chloramphenicol, sulfonamide, gentamicin, streptomycin, tetracycline, and sulfamethoxazole-trimethoprim) emerged and spread in Spain in 1997. Sequences specific for Salmonella serovar Typhimurium and phage type DT 104 and U302 were present in this atypical Salmonella ...

An fljB-negative, multidrug-resistant Salmonella enterica serovar 4,5,12:i:2 phage type DT U302 strain (resistant to ampicillin, chloramphenicol, sulfonamide, gentamicin, streptomycin, tetracycline, and sulfamethoxazole-trimethoprim) emerged and spread in Spain in 1997. Sequences specific for Salmonella serovar Typhimurium and phage type DT 104 and U302 were present in this atypical Salmonella ...

A water snake (Natrix natrix) was referred to the Small Animal Teaching Hospital, Faculty of Veterinary Medicine, University of Tehran. It had two subcutaneous masses. Radiographic and ultrasonographic images revealed the presence of two subcutaneous abscesses. The abscesses were removed surgically and specimens were examined by conventional microbial culture and multiplex PCR. Inv-A universal ...

SCharacterization of an Acid-Inducible Sulfatase in Salmonella enterica serovarTyphimurium LT2.113 ASM General Meeting, Denver, Colorado 2013.OmpR Regulates the Acid Inducible Arylsulfatase AslA in Salmonella enterica serovarTyphimurium LT2, 72 Annual Meeting of the North Central Branch American Societyfor Microbiology, Fargo, North Dakota, 2012.Genetic Regulation of Ary...