Microbial cross-contamination by airborne dispersion and contagion during defeathering of poultry

Abstract

1. A readily identifiable strain of Escherichia coli K12 was used as a 'marker' organism to determine the sources, routes and patterns of microbial cross-contamination during mechanical defeathering of broiler chicken carcases. 2. Inoculation of scald water with the marker organism led to a relatively even pattern of carcase contamination during subsequent defeathering. Microbial cross-contamination was greater by this route of inoculation than by either surface inoculation of a 'seeder' carcase or oral inoculation of a live bird one day before slaughter. 3. Dispersal of the marker organism was strongly influenced by the mechanical action of the defeathering machines. Forward transmission of the marker occurred by aerosol or large airborne droplets and particulates such as feathers. Moving carcases through the defeathering machines when these were non-operational clearly reduced backward transmission of the marker. 4. Although microbial dispersal was unaffected by increasing the spacing between individual carcases or installing a water curtain at the entry and exit of the defeathering machines, shielding of carcases with aluminium baffles reduced counts of the marker organism from contaminated carcases by > 90%. 5. The results imply that microbial cross-contamination of broiler chicken carcases during defeathering occurs mainly via the airborne route, which could be contained by physical means.

Transmission ofCampylobacterspp. in a poultry slaughterhouse and genetic characterisation of the isolates by pulsed-field gel electrophoresis

“…During slaughter mechanical evisceration often leads to intestinal rupture or leakage, followed by discharge of gut contents. Subsequently direct contact between carcases and contact of carcases with contaminated equipment surfaces can lead to horizontal transmission of faecal bacteria (Berndtson et al, 1996;Ono and Yamamoto, 1999;Berrang et al, 2001;Allen et al, 2003;Olsen et al, 2003). Our investigation showed that 8 out of 10 (80%) equipment samples were Campylobacter-positive (Table 3).…”

“…Our findings agree with those reported by Rhakio and Korkeala (1997) who concluded that airborne bacteria play an important role in carcase contamination. Allen et al (2003) also implied that the major route of cross-contamination is by airborne dissemination and that direct contamination with the components of the machine played a minor role. By taking into consideration the low infective dose of Campylobacter spp., of about 500 cells (Black et al, 1988), these appreciable concentrations of airborne bacteria have relevance for product safety as well as for the workers' health.…”

“…Although it has been shown that crosscontamination of meat products happens during the slaughter process including scalding defeathering, evisceration and chilling processes (Berndtson et al, 1996;Ono and Yamamoto, 1999;Berrang et al, 2001), there is still a lack of knowledge concerning possible transmission routes, and to what extent they are responsible for transferring Campylobacter to the surface of retail products. In addition to contamination via direct contact, cross-contamination of poultry meat products through the air has been reported in several investigations (Rhakio and Korkeala, 1997;Fries and Graw, 1999;Allen et al, 2003;Wilson, 2004). Oosterom et al (1983), Hagmar et al (1990), Berndtson et al (1996) and White et al (2001) demonstrated the existence of airborne Campylobacter spp.…”

Mechanically Ventilated Broiler Sheds: a Possible Source of AerosolizedSalmonella,Campylobacter, andEscherichia coli

“…However, analogies can be drawn from the survival patterns of these organisms in other aerosols environments such as processing plants or hatcheries. E. coli K-12 was able to survive in aerosols or large droplet particulates during defeathering of poultry (2). The levels of E. coli in processing plant air have been reported to range from log 10 1.18 to 1.67 CFU/15 cubic feet (defeathering areas) (45).…”

Identification of Bioaerosols Released from an Egg Production Facility in the Southeast United States

“…In animal production facilities, air often contains high concentrations of particulate matter (PM; organic and/or inorganic particles) and airborne microorganisms and other biologically active substances that are also known as bioaerosols (Thedell et al, 1980;Clark et al, 1983;Heber et al, 1988a, b;Donham, 1990;Maghirang et al, 1997;Donham and Comro, 1999;Bilic et al, 2000;Chang et al, 2001;Predicala et al, 2001;Allen et al, 2003;Ko et al, 2008Ko et al, , 2010. The main sources of bioaerosols are animal skin, feed, bedding materials, and fecal materials.…”