ABSTRACT
Salmonella enterica serovar Dublin (S. Dublin) is a bacterium host-adapted to cattle with increasing prevalence in dairy facilities. It can severely affect cattle health, producing high morbidity and mortality in young calves and reducing the performance of mature animals. Salmonella Dublin is difficult to control and eradicate from herds, as it can be shed from clinically normal animals. In addition, S. Dublin is a zoonotic bacterium that can be lethal for humans and pose a risk for human and animal health due to its multi-drug resistant characteristics. This review provides an overview of S. Dublin as a pathogen in dairy facilities, the risk factors associated with infection, and current strategies for preventing and controlling this disease. Furthermore, current gaps in knowledge are also discussed.
ABSTRACT
Aquaporins (AQPs) are proteins with various functions related to proper cell function and early development in mammals. The aim of this study was to evaluate the presence of AQPs and determine their mRNA levels in the cumulus oocyte complex (COC) of four bovine breeds and in blastocysts of five bovine crosses. Grade I, II and III COCs were collected by ovum pick up from non-lactating heifers of the Brahaman, Holstein, Gir and Romosinuano breeds. Embryos were produced in vitro up to the blastocyst stage of the bovine âGir × âHolstein, âHolstein × âGir, âBrahman × âHolstein, âHolstein × âBrahman, and âRomosinuano × âHolstein crosses. mRNA expression of AQP1-AQP12b was estimated in COC and embryos by real-time-PCR. The presence of the twelve AQPs in the COCs and bovine embryos was established. Additionally, significant differences were determined in the expression of AQP6 and AQP12b in COCs, as well as in transcripts levels of AQP4, AQP8 and AQP9 from bovine embryos. Gene expression of AQPs in COCs and bovine embryos is consistent with the previously described biological functions. This is the first report of AQPs in COC of Gir, Brahman, Holstein and Romosinuano and embryos of five crossbreeds between Bos indicus and B. taurus.
ABSTRACT
BACKGROUND AND AIM: Salmonella is one of the most common foodborne pathogens, the emergence of antibiotic-resistant strains of which is increasing. The aim of this study was to phenotypically and genotypically characterize the fluoroquinolone resistance of Salmonella isolates from broiler and humans in two regions of Colombia. MATERIALS AND METHODS: Salmonella strains (n=49) were evaluated. The phenotype of antibiotic resistance was assessed by an automated method and agar diffusion method, as well as the presence of the quinolone resistance genes qnrA, qnrB, qnrC, qnrD, qnrS, and aac(6')-Ib as determined by polymerase chain reaction. RESULTS: Strains were resistant to ciprofloxacin (75%), levofloxacin (57.1%), and enrofloxacin (38.8%). Molecular identification showed that 24 out of 49 strains possessed the qnrB gene (48.9%), while only one isolate from the Santander region possessed the aac(6')-Ib gene. Regarding Class 1 integron, it was present in 11 out of the 49 strains (22.44%). CONCLUSION: This study reports the presence of the gene qnrB as well the presence of Class 1 integrons in broiler Salmonella isolates, which may contribute to the resistance to fluoroquinolones.
ABSTRACT
Salmonella enterica is the most important foodborne pathogen, and it is often associated with the contamination of poultry products. Annually, Salmonella causes around 93 million cases of gastroenteritis and 155,000 deaths worldwide. Antimicrobial therapy is the first choice of treatment for this bacterial infection; however, antimicrobial resistance has become a problem due to the misuse of antibiotics both in human medicine and animal production. It has been predicted that by 2050, antibiotic-resistant pathogens will cause around 10 million deaths worldwide, and the WHO has suggested the need to usher in the post-antibiotic era. The purpose of this review is to discuss and update the status of Salmonella antibiotic resistance, in particular, its prevalence, serotypes, and antibiotic resistance patterns in response to critical antimicrobials used in human medicine and the poultry industry. Based on our review, the median prevalence values of Salmonella in broiler chickens, raw chicken meat, and in eggs and egg-laying hens were 40.5% ( interquartile range [IQR] 11.5-58.2%), 30% (IQR 20-43.5%), and 40% (IQR 14.2-51.5%), respectively. The most common serotype was Salmonella Enteritidis, followed by Salmonella Typhimurium. The highest antibiotic resistance levels within the poultry production chain were found for nalidixic acid and ampicillin. These findings highlight the need for government entities, poultry researchers, and producers to find ways to reduce the impact of antibiotic use in poultry, focusing especially on active surveillance and finding alternatives to antibiotics.
