A Study of Common Pathogens in Poultry Industries in Ifite-Ogwari, Anyamelum Local Government Area of Anambra State, Nigeria

The poultry industry is susceptible to a wide range of bacterial, viral, fungal, and parasitic pathogens. Bacterial pathogens, including Salmonella spp., Escherichia coli, Campylobacter spp., and Staphylococcus aureus are among the most common culprits responsible for disease outbreaks in poultry. They cause high mortality and productivity losses in poultry (Tamer et al., 2020).

Salmonella enterica causes foodborne enteric disease worldwide, representing the second most commonly reported zoonotic pathogen in the world (Lorenzo-Rebenaqu et al., 2022). It is responsible for disease outbreaks associated with significant morbidity and mortality (Ricke et al., 2021). And up to 25% of human Salmonella outbreaks, illnesses and hospitalizations are related to poultry sources (Chai et al., 2017). Salmonella are gram-negative, facultative anaerobic bacteria belonging to the Enterobacteriaceae family, and are considered commensals of the gut microbiota of mammals, birds, reptiles, amphibians, fish and shellfish (Cosby et al., 2015). S. enterica includes more than 2650 serovars (Issenhuth-Jeanjean et al., 2014), and many are implicated as contaminants of poultry meat and eggs, representing a serious concern for public health (Antunes et al., 2016). In poultry, diseases due to S. enterica may be grouped into three namely fowl typhoid, pullorum disease and avian paratyphoid. Young poultry are particularly susceptible to gastrointestinal tract (GIT) colonization by S. enterica. Its excretion in feces may result in the contamination of the environment and the infection of nearby birds (Cosby et al., 2015). Moreover, poultry meat contaminated with digesta during slaughter is a major risk to public health (Alali et al., 2018).

Campylobacter spp. are ubiquitous bacteria that can be found in various environments, including soil and water, and as commensals of the GIT of poultry. Despite this, they can cause disease in animals and humans and constitute an important cause of foodborne diseases worldwide (Silva et al., 2011). This bacterial genus can be responsible for acute bacterial diarrhea, which is mainly caused by C. jejuni and C. coli. Although other sources can be responsible for human infection, poultry products are considered the predominant source of human campylobacteriosis (Rickie et al., 2021). Campylobacter spp. can be introduced in the production farms by wild animals, pests or humans. When infecting poultry, it colonizes the GIT osanimals, invades the intestinal epithelium and multiplies rapidly in the intestinal mucus, avoiding clearance and persisting in the animal’s GIT (Van Deun et al., 2008). In this way, avian hosts constitute a natural reservoir for Campylobacter spp., namely C. jejuni and C. coli (Sahin et al., 2015). According to the European Food Safety Authority (EFSA) and European Centre for Disease Prevention and Control (ECDC), the highest prevalence of Campylobacter is observed in fresh meat from broilers (37.5%). Although carriers of Campylobacter spp. chickens generally do not exhibit clinical signs. Antibiotics have a limited role in the elimination of Campylobacter spp. by these animals due to its high occurrence and commensal character in avian species, and can promote the emergence of resistant strains; therefore, biosecurity practices are the most important method for reducing Campylobacter infection at the production level (Hermans et al ., 2012).

Human infections are usually associated with the handling, preparation and consumption of contaminated poultry products, and occupational transmission has also been observed. In humans, these pathogens cause gastroenteritis associated with diarrhea, abdominal pain, fever, nausea and vomiting, which usually occur between two and five days after infection. Symptoms are often mild and self-limiting. Antibiotic treatment is not usually required, but severe cases may be treated with macrolides, such as clarithromycin, azithromycin and erythromycin. Ciprofloxacin is not currently used, as resistance to quinolones is now considered to be too high for these antibiotics to be used as an empirical treatment (Sahin et al., 2015). Studies on the antimicrobial drug resistance profile of Campylobacter spp. Isolated from broilers, laying hens, chicken carcasses and Chicken meat revealed high frequencies of resistance to nalidixic acid, ampicillin, cephalexin, ciprofloxacin, erythromycin, Gentamicin and tetracycline (de Saraiva et al., 2022).

E.coli is a gram-negative bacillus belonging to the Enterobacteriaceae family (Daneshmand et al., 2019). It is an important bacterial species in the Human–animal–environment triad, since it is a commensal inhabitant of the digestive tract of animals, including birds, being widely spread via fecal material (Islam et al., 2021). This species is often studied as a marker of antimicrobial drug resistance, mainly Due to its widespread distribution and capacity to harbor several genes in mobile genetic elements, serving as a source of Antimicrobial drug resistance determinants to other bacteria (Bass et al., 1999). Most E. coli are nonpathogenic; however, certain pathogenic serotypes may induce disease. There are several E. coli Pathotypes, which can be divided into extra intestinal E. coli (ExPEC) and diarrhoeagenic E. coli (DEC). Avian pathogenic E. Coli (APEC), an ExPEC, may induce colibacillosis in domestic birds, a disease characterized as a local or systemic syndrome That can be transmitted by oral or vertical routes or through inhalation. E. coli-associated infections are widely distributed among poultry of all ages. Birds can be asymptomatic until sudden death or present various forms of disease, such as Septicemia, coligranuloma (Hjarre’sdisease), air sac disease (chronic respiratory disease), swollen-headsyndrome, venerea lColibacillosiscellulitis, peritonitis, salpingitisorchitis, osteomyelitis/synovitis, panophthalmitis, omphalitis/yolk sac infection and enteritis (Nolan et al., 2013). Colibacillosis constitutes the most frequent infectious bacterial disease found in poultry, being responsible for significant economic losses due to the loss of productivity, increased mortality and condemnations of carcasses (Żbikowska et al., 2020).

Enterococcus species are ubiquitous and are commensals of the gastrointestinal microbiota of both humans and animals. Some enterococcal strains have been used as probiotics (Kabir et al., 2009), while others are known to be pathogenic, including in birds (Souillard et al., 2022). The transmission of enterococci can occur via vertical and horizontal routes. E. cecorum and E. faecalis are the most Important species associated with avian disease. Pathogenic strains of E. cecorum have been associated with free thoracic Vertebra (FTV) osteomyelitis in broilers (Devriese et al., 2002), resulting in the paralysis of the posterior limbs, and with septicemia related to Pericarditis or hepatitis, which can lead to death. In turn, E. faecalis can cause omphalitis and yolk sacculitis, which can lead To sepsis and the death of chicks in the first week of life. Surviving animals may develop chronic diseases, such as valve endocarditis, which can also lead to death (de Saraiva et al., 2022). Enterococcus spp. can easily acquire resistance determinants and, therefore, playa central role in AMR dissemination. Vancomycin-resistant Enterococcus (VRE) has been associated with economic losses in animal production and healthcare And associated with infections in humans (Khan et al., 2015). Humans are exposed to enterococci from a variety of sources, including other Humans, the environment and foods contaminated with animal’sintestinal microbiota. Certain species, such as E. faecalis and E. faecium, are a prominent cause of opportunistic infections in hospitalized humans, causing mild to fatal diseases, such as Endocarditis, urinary tract infections or septicemia (Dea et al., 2019). Studies previously performed have identified high levels of Resistance against aminoglycosides (streptomycin), tetracyclines (doxycycline and tetracycline) and quinolones (ciprofloxacin and enrofloxacin) in enterococci isolated from poultry (de Saraiva et al., 2022). Vancomycin resistance, which is reported as infrequent, can be higher in isolates from chickens affected with FTV. In view of these havocs emanating from these bacterial pathogens, this study was designed to isolate and characterize the major pathogens associated with poultry production in Ifite-ogwari of Ayamelum local government area of Anambra State, Nigeria.