A review on major bacterial causes of calf diarrhea and its diagnostic method

Abstract

Calf diarrheic diseases result from complex interactions of the environment. Infectious agents and the calf itself are the major constraints for raising replacement stock. Calf diarrhea is a multi factorial disease entity that can have serious financial and animal welfare implications in both dairy and beef sucker herds and is one of the most common diseases reported in calves up to 3 months old. Among the bacterial causes of diarrhea in neonatal food animals, Escherichia coli and Salmonella species are the most common and economically important ones. Clostridium perfringens and Campylobacter species have also been identified as causes of enteric diseases in calf diarrhea other, Non-infectious factors, such as insufficient uptake of colostrum, poor sanitation, stress, overcrowding in the calf pens and cold weather, could cause neonatal calf diarrhea. The most prominent virulence factors identified in bacterial diarrhea are expression of fimbrial (pili) antigens that enables the bacteria to adhere and to colonize the luminal surface of the small bowel and elaboration of one or more enterotoxins that influence intestinal secretion of fluids. Various laboratory methods have been applied for the detection of infectious agents of calf diarrhea in fecal sample such as, bacterial culture, electron microscopy, molecular based techniques (PCR, DNA microarray) and serological techniques (enzyme-linked immunosorbent assay, latex agglutination test). Accurate and rapid early confirmation of the etiology in the disease outbreak as well as improving the various management factors are advised, for effective control and prevention of enteric disease in newborn calves. Treatment with rehydration solutions and provision of dry and warm conditions are vital in the treatment of calf diarrhoea.

Comparison of Diagnostic Tests for Detection of Bovine Rotavirus a in Calf Feces

“…Rapid test would be a very effective cow side diagnostic test because of its simple application and quick result. Rapid test has a number of advantages, including its simple format, rapidity, low-cost, and it can be performed without trained personnel or specialized laboratory equipment (24). Moreover, it can be interpreted without using equipment, thus making it easily usable for any laboratory or farm.…”

“…However, specificity was 100% for both. Since, nucleic acid-based assays are generally much more sensitive than antibody-based assays for antigens (24), the observed result of RT-qPCR for the detection of BRVA in feces may be more acceptable as diagnostic tool. But it should be noted that RT-qPCR needs laboratory equipment, skilled personnel as well as highly costly materials; whereas rapid test can be implemented on the spot.…”

Pathotyping and antimicrobial susceptibility testing of Escherichia coli isolates from neonatal calves

“…Infectious causes lead to neonatal diarrhoea or calf scour, septicaemia and pneumonia (Kochewad et al 2013). Acute diarrhoea is the main reason behind 75% neonatal calf mortality during pre-weaning period (Muktar et al 2015).…”

“…Along with these, poor hygienic condition of shed and nearby surrounding, overcrowding in calving shed and neonate's calf shed and close association with adult cows and housing of various age groups together contribute towards risk factors associated with NCD. Along with the stated non-infectious factors, other factors like low temperature and/or contaminated incoming air and inadequate ventilation also play role in lowering the defence mechanism in early age of calf (Lance et al 1992;Tewari 2012;Muktar et al 2015).…”

Genotypic analysis of virulence genes and antimicrobial profile of diarrheagenic Escherichia coli isolated from diseased lambs in Iran

“…have also been linked to this disease. Among these pathogenic agents, E. coli is the most common and important once (Muktar et al 2015).…”