Establishment of a pathogenicity index in Salmonella Enteritidis and Salmonella Typhimurium strains inoculated in one-day-old broiler chicks

Abstract

Salmonella Enteritidis and Salmonella Typhimurium are responsible for causing huge economic loses in aviculture, as they lead young broiler chicks to develop clinical disease and thus increase mortality. Salmonella's pathogenicity is considered complex and multifactorial, demanding more studies that could elucidate the interaction between host and pathogen. The present study aims to evaluate the virulence of 130S. Enteritidis isolates and 70S. Typhimurium inoculated in one-day-old chicks through the establishment of a pathogenicity index. For each strain, 10 commercial chicks from the Cobb lineage were used. Then, 200µL of a solution containing 2x10 8 CFU of S. Enteritidis or S. Typhimurium were inoculated in the birds by intraperitoneal via. Mortality and presence of lesions such as aerosaculitis (A), perihepatitis (Ph), pericarditis (Pc), peritonitis (Pt), onfalitis (O) and cellulitis (C) were registered daily for seven days. From the second to the seventh day there was a proportional decrease in the punctuation of the time of death (TD) for each day that the bird had survived. The pathogenicity index was calculated using the following formula: PI = (TD x 5) + A + Ph + Pc + Pt + O + C. The obtainment of the PI of each bacterial sample was achieved by calculating the rate of the ten inoculated birds. Based on the obtained results, it was possible to attribute the pathogenicity value for each strain, which enabled us to classify them in groups of low (27/200), intermediate (95/200) and high (78/200) pathogenicity. The utilization of standards like time of death and presence of septicemic lesions made it possible to determine the pathogenicity rate for each strain. Besides that, the proposed model has presented dramatic differences between the high, intermediate and low pathogenicity groups, which makes this mechanism useful for further classification of strains isolated in poultry farms.

Pharmacokinetic and pharmacodynamic integration of enrofloxacin against Salmonella Enteritidis after administering to broiler chicken by per-oral and intravenous routes

“…The incidence of this infection is the greatest in children, the elderly, and immunosuppressed individuals [2]. A significant proportion of all cases of human salmonellosis is known to be caused by the consumption of contaminated raw or improperly cooked poultry products (both eggs and meat) [3]. Salmonella enterica ssp.…”

Pathogenicity of Salmonella enterica subspecies enterica serovar Enteritidis phage type 1 in one-day-old specific pathogen free chicks

“…There were 2 (6%) dead chicks. However, in a study conducted by Lima et al (2016) , it was found that the mortality rate, in one-day-old chicks experimentally infected with different strains of SE, was 69.5%. Also, in an outbreak of Salmonella in many poultry farms in four states in Nigeria, the mortality rate was ranging from 40% to 80% ( Mshelbwala et al , 2017 ).…”

Bacteriophages and their derivatives for the treatment and control of food-producing animal infections

“…Bacterial genera and virus families that cause disease in food-producing animals (Bradley et al, 2015;FAO, 2015;Merck, 2015;Persson & Bojesen 2015;VetBac, 2015). tuberculosis, staphylococcosis, streptococcosis, infectious coryza, necrotic enteritis, avian chlamydiosis, colibacillosis and mycoplasmosis (Hao et al, 2014;Lima et al, 2016;Masdooq et al, 2008;Merck, 2015).…”

“…In poultry, promising results were obtained for phage therapy against Salmonella enterica serotypes Typhimurium and Enteritidis, which may cause disease especially in young chicks (Lima et al, 2016). The importance of using phage cocktails and administering high and multiple doses of phages was also demonstrated (Berchieri et al, 1991;Fiorentin et al, 2005;Sklar & Joerger, 2001).…”