As the result of the highest count was observed in evisceration and final washing stage,which was decreased during in final washing after evisceration, the number of total mesophilic bacterial count by more than 1 log cycle which is compatible with a report reported by Goksoy et al. (2004) (James et al., 2000). Nevertheless, the rate of decrease in total coliform count, total faecal coliform count and total Staphylococci count were less compatible which may be due to the strong attachment of these microorganism in chicken and less effective of washing process applied in the plant (Althaus et al., 2017).
A significant changes in bacterial count occurred at freezing steps which reduced the number of total bacterial count by 1 log cycle. Cooling and freezing of poultry meat has great influence on poultry meat microflora as cold condition has reduced microorganisms (James et al., 2006). During freezing of poultry the destruction of microorganisms occurs but this destruction is never absolute and is only interested in a limited number of microorganisms, which may be higher or lower depending on type of microorganisms (Mbata, 2005).
The total aerobic plate count 4.45 log CFU/g in market meat of this study is consistent with previous studies conducted by Chaudhey et al. (2011) (5.07 log CFU/g) (Chaudhrya et al., 2011). Sengupta et al. (2012), Omorodion and Odu (2014), and Bhandari et al. (2013) have reported higher counts of total aerobic bacteria 6.39 log CFU/g, 5.96 log CFU/g and 7.24 log CFU/g respectively in market chicken meat (Ibrahim et al., 2015; Omorodion & Odu, 2014; Bhandari et al., 2013). On the other hand, lower counts were reported by Rindhe et al. (2008) (3.67 log CFU/g) (Rindhe et al., 2008), and Al-jasser et al. (2012) (4.03 log CFU/g) (Al-Jasser, 2012). Total viable count in raw poultry indicates hygienic conditions of processing plants under which the food are processed and high load increases the risk of microbial spoilage (Cohen et al., 2007; Javadi & Safarmashaei, 2011). Studies have shown the correlation of food spoilage with the total bacterial count on the surface part of carcass: off-odor and sour are the noticeable evident when the bacterial count on carcass reached about 107 CFU/g and visible slime formation can be observed when the count reached approximately 108 CFU/g threshold (Wabeck, 2002).
In this study, total coliform count 2.19 log CFU/g of market meat was similar with results reported by Capita et al. (2002) (2.7 log CFU/g) and Northcutt et al. (2003) (2.6 log CFU/g) (Capita et al., 2002; Northcutt et al., 2003). In contrast, less coliform counts were reported by Joshi et al. (1.03 log CFU/g) and Selvan et al. (2007) (1.13 log CFU/g) (Joshi & Joshi, 2010; Selvan et al., 2007) while higher coliform counts were found in studies conducted by Kumar et al. (2012) (4.97 log CFU/g), Sengupta et al. (2012) (32.2 log CFU/g), and Bhandari et al. (2013) (6.5 log CFU/g) (Ibrahim et al., 2015; Bhandari et al., 2013; Selvan et al., 2007). In this study, total faecal coliform count was absent in market meat. E. coli was used as an indicator organism of sanitary quality and potential faecal contamination of meat which can originate even from workers or environment of the processing plant (Wabeck, 2002). E. coli count in poultry products can be minimized by controlling cross contamination, maintaining sanitary practices, and temperature of carcass. It is necessary to ensure hygienic food production for the safeguard of public health (Althaus et al., 2017).
The count of total Staphylococci 1.99 log CFU/g in market meat was lower than the studies carried by Sengupta et al. (2012) (3.7 log CFU/g), Joshi et al. (2010) (4.07 log CFU/g) (Joshi & Joshi, 2010; Sengupta et al., 2012). Presence of Staphylococci in meat reflects insanitary condition, cross contamination between processing phase, and surrounding environment, processing temperature and personal contact. Staphylococcus aureus is a commensal organism of human skin and also a common pathogen, which causes minor to severe infections including food poisoning (Carroll et al., 2015). In a study conducted by Hotee et al. (2011) at the Central Health Laboratory in Mauritius have isolated S. aureus as the second common pathogen from analyzed food samples (Heetun et al., 2015). The presence of 17.1% S. aureus in market meat of this study is in agreement with the study conducted Kozacins et al. (2012) where prevalence was 17.9% (Kozačinski et al., 2012). In contrast, Joshi and Joshi (2010) had reported higher prevalence of S. aureus (100%) in meat (Joshi & Joshi, 2010). Generally chicken meat becomes contaminated with S. aureus when an infected person does coughing, sneezing, talking or breathing inside the plant (Wabeck, 2002). The microbial load were found in initial processing step, comprising the receiving-killing and defeathering areas, whereas count towards the evisceration, air chilling, packaging and dispatch area decreased (James et al., 2000; Hinton Jr et al., 2004).
Another important pathogen of meat contamination is Salmonella which habitats in the intestinal tract of animals and shed along with feces of the animals that makes its presence in surrounding environment (Wabeck, 2002). In this study, Salmonella spp. was not detected in market chicken meat. As we applied plating culture technique for the isolation of Salmonella spp. so we can’t claim that Salmonella spp. were completely absent. There could be viable but non-culturable cells of the strain. Similar findings have been reported by Vaidya et al. (2005), and Lindblad et al. (2006) (Vaidya et al., 2005; Lindblad et al., 2006). In contrast, in another study carried by Joshi and Joshi (2010) had reported Salmonella spp. in all the examined chicken carcasses (100%) (Joshi & Joshi, 2010). On the other hand, lower percentage of Salmonella spp. was reported by Cohen et al. (2007) (1.6%); Abdellah et al. (2008) (2.08%); Colmegna et al. (2009) (1.1%) (Cohen et al., 2007; Abdellah et al., 2008; Colmegna et al., 2009). Presence of Salmonella spp. in market meat of chicken suggests poor hygienic status of meat processing plant during slaughtering, cross contamination between machines, scalding tanks, defeathering machines, and workers. During the slaughtering and manual evisceration process of intestinal contents may spill and contaminate the muscle and organs of the chicken which is an important source of Salmonella spp. contamination in meat and water chilling tanks (Colmegna et al., 2009).
Clostridium perfringens is an obligate anaerobe which is found in the alimentary tract of poultry. C. perfringens was not isolated in chicken meat samples of this study which complies with the study carried by Shaltout et al. (2009) in Egypt (Shaltout, 2009). On the other hand, C. perfringens were isolated by Chhetri and Karki (2014) (80.8%) in raw poultry meat of Kathmandu; Nowell et al. (2010) (66%) in Canada; Cohel et al. (2007) (7.2%) in Casablanca (Morocco) and Thangamani and Subramanin (2012) (3.81%) in Tamilnadu, India (Cohen et al., 2007; Nowell et al., 2010; Thangamani & Subramanian, 2012; Chhetri & Karki, 2014). If the raw meat originally contains C. perfringens, it is almost impossible to make final product free from this contamination since heat treatment only destroys vegetative cells of this bacterium activating spores for further germination (Van Immerseel et al., 2004).
Listeria spp. do spread either by inhalation or direct contact. Listeriosis typically occur after consumption of contaminated foods. For humans contaminated sources include raw meat (Reiter et al., 2005). In this study, Listeria spp. was not isolated from the chicken meat samples during the slaughter process which was similar with another study reported by Svobodova et al. (2012) (Svobodová et al., 2012). Prevalence of L. monocytogenes was reported by Colmegna et al. (2009) (3%) in Milano, Italy; Kozacins et al. (2012) (4.5%) in Croatia; Molla et al. (2004) (1.9%) in Addis Ababa, Ethiopia and Cohen et al. (2007) (0.5%) in Casablanca (Morocco) (Cohen et al., 2007; Kozačinski et al., 2012; Colmegna et al., 2009; Molla et al., 2004). Loura et al. (2004) have reported frequent findings of L. monocytogenes on poultry cuts and especially, on the hands of poultry processing plant staffs, poultry processing plant desks and equipment (Gottlieb et al., 2006). L. monocytogenes is well documented as a major foodborne pathogen in the different parts of the world which is habitat event in natural environments like mud, soil, water, sewage, gut of poultry and feces (Yeh, 2004).
The tank water is present with high load of total viable count 3.2 log CFU/ml and coliform 1.2 log CFU/ml. After water treatment in water treatment plant and chlorine dosing, processing water (Pipeline water) is nearly free of contamination showing acceptable microbiological water quality with total viable count of 2.5 log CFU/ml, nil coliform and faecal coliform. The total plate count is an indirect indicator or index for pathogens of concern in water, which helps in assessing the efficacy and proper functioning of water treatment and supply process and is related to the acceptability of water (Figueras & Borrego, 2010).
Air microflora in abattoir changes with rate of movement of people from one place to another, hygienic condition, humidity and room temperature (Haagsma et al., 2012). So, in order to monitor air quality, the plate exposure method was applied in this study for total mesophilic bacterial count and total yeast and mold count which showed that lairage was most contaminated whereas packaging, grading, and spin chilling section showed least contamination.. The presence of fungi in abattoir air may be due to migration from outdoor environment as well as presence in ceilings and walls of production area (Update, E. H. E. D. G, 2006). In poultry processing plants, the reception of birds is the major source of air pollution with pathogenic microorganisms. Along the processing phase of poultry processing plant air microflora tends to decrease reaching the lowest values in the freezing (Whyte et al., 2001). Findings of this stay are in agreement with the data reported by Whyte et al. (2001), they have reported that microbial contamination of the air was widespread and varied considerably between different processing locations of a poultry processing plant (Whyte et al., 2001).
The presence of high load of bacteria on the floor poultry processing plant may be due to cross- contamination of litter as chicken faeces are rich in microorganisms (Svobodová et al., 2012). During this study, the cleanliness of table, equipment, machine, buckets used in the poultry processing were assessed to check the standards of hygiene and efficiency of cleaning procedures. In this study, there was high load of total mesophilic bacterial count indicating lack of good cleaning practices which ultimately played a great role in cross-contamination of poultry meat. Contaminating bacteria on the equipment would soon be found on meat in various parts of the carcasses by increasing their microbial load and reducing their storage quality and safety (Bhaisare et al., 2014). Implementation of HACCP system in the food industry and even in home can maintain food safety by eliminating or reducing food-borne hazards (Wallace, 2014). Many researches have shown that application of HACCP systems in food industry leads to more efficient prevention of food-borne diseases (Scoti & Stevenson, 2006; Pal et al., 2016).