MICROBIOLOGICAL CONTAMINATION OF LAMB CARCASSES AT ABATTOIRS OF ISTANBUL

A total of a hundred lamb carcasses were sampled over a 12 month period at abattoirs in Istanbul, Turkey. Each sample examined for total aerobic mesophilic counts (TMC), Enterobacteriaceae count (EC), Salmonella spp., Escherichia coli O157:H7 and Listeria monocytogenes was obtained from 100 cm2 areas on four sides of lamb carcasses using the wet and dry cotton swab technique. The study revealed that total aerobic mesophilic counts in all carcasses ranged between 4.18 and 5.95 log/cm2; Enterobacteriaceae counts between 1.60 and 2.30 CFU/cm2. All samples were negative for Escherichia coli O157:H7 and Listeria monocytogenes. Furthermore Salmonella spp. was detected on four carcasses. The data confirms bacteriological monitoring of lamb carcasses as a useful criteria for the verification of slaughter hygiene.

tions associated with infection include septicemia or reactive arthritis Š18¹.Approximately 31% of all food-related deaths are caused by Salmonella spp.infections in the United States every year.
Listeria monocytogenes is a pathogen that causes severe illnesses, listeriosis, in populations at risk Š9¹.Listeriosis, a fatal infection (up to 30%) in human and animal species, has severe consequences such as abortion, septicemia, meningitis and encephalitis Š12¹.It has been isolated from raw and pasteurized milk, soft cheese, ice cream, raw meat, poultry, raw fish, read to eat products, fermented sausages, vegetables, food processing plants and soil Š16¹.In the United States, listeriosis is responsible for 3.8% of foodborne illness -related hospitalization and 27.6% of foodborne disease -related deaths Š13¹.
Escherichia coli O157:H7 is one of the most important neurotoxin producing enterohemorrhagic E. coli.It rarely produces clinical disease in animals but is associated with hemolytic uremic syndrome, thrombocytic thrombocytopenic purpura and hemorrhagic colitis in human Š14¹.E. coli O157:H7 bacteria is believed to mostly live in the intestines of cattle Š5¹ but has also been found in the intestines of sheep, pigs, deer and goats Š4¹.An estimated 73.000 cases of infection and 61 deaths occur in the United States each year.
Contamination of these microorganism from the hide to the carcass is unavoidable due to the nature of hide removal.Contamination can occur by direct contact between the hide and the carcass, or by contact between the carcass and operatives' hands, clothes, tools or factory equipment that had previously been in contact with the hide.
At the same time, 2001/471/EC, which was introduced by the EU, relies on the use of total viable counts and Enterobacteriaceae as indicators of carcass hygiene and feacal contamination Š2¹.
With the implementation of Hazard Analysis Critical Control Point (HACCP) and Quality Management (QM) systems at abattoirs there are increasing requirements for the microbiological sampling of carcasses.Carcass contamination during the slaughter process results in hygiene deficiencies which cannot be compensated for even by the most rigorous hygiene measures during latter processing states of the raw material.This underlines the great significance of slaughter hygiene.Therefore, verification of the efficiency of slaughter hygiene by microbiological examination of carcasses is desirable Š20¹.This study examined the microbial contamination of lamb carcasses surfaces after slaughter to determine the acceptability of carcass hygiene levels and prevalence of the foodborne pathogens Salmonella spp., E. coli O157:H7 and Listeria monocytogenes.

Plant Process / Proces u klanici
Twenty-eight visits were made to two different abattoirs in Istanbul.These abattoirs were established with goverment collaboration.Each of the abattoirs consist of a lairage, slaughter floor, dressing cradle, chilling room, cutting room and veterinary service office.One of these slaughterhouses has a capacity of 2000-2500 sheep/day, 200-250 cattle/day and the other's capacity is 200-250 sheep/day, 30-35 cattle/day.All required equipment such as rail system, stunning devices, restraining equipment, stainless steel holding bins and tables were provided.In this survey, a hundred carcasses were sampled.No more than four carcasses were sampled at each abattoir per visit.The carcasses were randomly selected from a batch of four consecutive lambs to avoid any large differences in carcass contamination.

Carcass Sampling / Uzorkovanje trupova
The sampling was performed within 2 hours at postmortem.All samples were taken from the left halves of the carcasses at four parts; the brisket, the breast, the neck and the flank using double swab technique.A 100 cm 2 sampling area was delineated using a sterile stainless steel template and using a wet swab, moistened in 0.1% peptone + 0.85% NaCl diluent and a dry swab.The handles of the swabs were broken off, leaving the swab tips in the tubes, containing 10 ml of maximum recovery diluent (MRD).The swabs were transported to the laboratory at 4 o C.

Microbiological Analysis / Mikrobiolo{ka analiza
After the samples were delivered to the laboratory, each tube containing the swabs was homogenized for 2 minutes in 100 ml of MRD.Samples were examined within 6 hours after sampling.

Total Mesophilic Aerobic Count (TMC) / Ukupan broj aerobnih mezofila (TMC)
Diluted samples were plated in duplicate onto plate count agar (Merck 1.05463).Plate count agar plates were incubated at 37 o C. The colonies grown in plate count agar (PCA) were determined as TMC and the observed colonies were enumerated after 48 h from incubation.

Enterobacteriaceae Count (EC) / Broj Enterobacteriacea (EC)
For detection of Enterobacteriaceae, ISO 5552 was used.Diluted samples plated in duplicate on to violet red bile dextrose agar (VRBDA, Merck 1.10275).VRBDA plates were incubated at 37 o C at 24 h.Enterobacteriaceae colonies were enumerated on VRBDA agar, and they were observed as dark red colo-Materials and methods / Materijal i metode rada nies that are 1-2 mm or larger in diameter and surrounded by a zone of precipitated bile acids.
Detection of Escherichia coli O157:H7 / Nalaz Escherichia coli O157:H7 For detection of E. coli O157:H7, the FDA method was used Š1¹.Each MRD tube that contains a sample swab was added into bottles made of borosilicate glass containing Modified EC broth (Oxoid CM 990) with novobiocin supplement (Oxoid SR0181E), and the bottles were incubated for 24 hours at 37 o C.This part was the enrichment step of the inoculation procedure for E. coli O157:H7.
The inoculum was vortexed and was inoculated with loop to the Sorbitol Mac Conkey Agar (Merck 1.09207.0500)with Cefixime Tellurite supplement (Merck 1.09202) After the incubation period at 35 o C for 18 hours, the colourless or smoggy grey colonies were determined as suspicious bacteria.Typical colonies that are growth were taken and inoculated to the Triptic Soy Agar (Merck 1.05458.0500)with 0.6% yeast extract (Merck 1.03753.0500).After the incubation of the colonies at 37 o C for 12 hours, E. coli O157 the latex agglutination test (Oxoid DR 0120) was applied to the grown colonies for recovery.

Detection of Listeria monocytogenes / Nalaz Listeria monocytogenes
For detection of Listeria monocytogenes, the FDA method was used Š1¹.Each pepton water tube that contained a sample swab was added into the bottles containing Fraser broth (Merck 1.10398) with Half Fraser Listeria Supplement (Merck 1.10399) and was added into the bottles containing Fraser broth (Merck 1.10398) with Fraser Listeria Supplement (Merck 1.10399).Half Fraser Broth bottles were incubated for 24 hours at 30 o C. Fraser Broth bottles were incubated for 24-48 hours at 35-37 o C.This part was the enrichment step of the inoculation procedure for Listeria monocytogenes.
The inoculum was vortexed and was inoculated with loop to the OXA (Merck 1.07004) and PALCAM agar (Merck 1.11755).After the incubation period at 35 o C for 24-48 hours, black-brown colonies on the OXA and grey-brown green colonies with a black halo on the PALCAM agar were determined as suspicious bacteria.
Five or more typical colonies that are growth on the OXA and PALCAM agar were taken and inoculated to the Triptic Soy Agar (Merck 1.05458.0500)with 0,6% yeast extract (Merck 1.03753.0500).TSAYE plates were incubated at 30 o C for 24-48 hours for recovery.For identification procedure, the FDA methods was used.
For serology, the CAMP test was used.To perform the test, streak a beta-hemolytic Staphylococcus aureus and a Rhodococcus equi culture in parallel and diametrically opposite each other on a sheep blood agar plate.Streak several test cultures parallel to one another, but at right angles to and between the S. aureus and R. equi streaks.After incubation at 35 o C for 24-48 h, examine the plates for hemolysis.
Detection of Salmonella spp./ Nalaz Salmonella spp.After enrichment of the buffered peptone water for 24 h at 37 o C, 0,1 ml was transferred to 10 ml Rappaport Vassiliadis broth (RV, Oxoid) and 10 ml transferred to 100 ml selenite cysteine broth (Merck 1.07709).The broths were incubated at 42 o C and 37 o C, respectively, for 24 h.Aliquots from each broth were spread, in duplicate, onto salmonella-shigella agar (SS, Merck 1.07667) and brilliant green phenol red lactose agar (BGPRA, Merck 1.07236) plates, and incubated at 37 o C for 24 h.After plating, the selenite cysteine broths were returned to the incubator for a further 24 h, and plated out as described above.Suspicious colonies on either SS or BGPRA were confirmed using Gram staining, catalase, oxidase, urease, indole, simmons citrate, the Voges-Proskauer test, methyl red test, glucose (TSI), lysine decarboxylase and semi indole motility tests, poly O and H antisera (Prolab) and Api 20E kits (Biomerieux).
Slaughtering is an open process with many opportunities for the contamination of the carcass with potentially pathogenic bacteria.Microbial contamination results in reduced shelf life of meat, spoilage of meat and public health hazards.The aim of this study was to examine the microbial contamination of lamb carcass surfaces after slaughter, to determine the acceptability of carcass hygiene levels and prevalence foodborne pathogens at the abattoirs in Istanbul.
A total of a hundred lamb carcasses were sampled over a 12 month period.Each sample was analysed for Total Mesophilic Aerobic Count, Enterobacteriaceae Count, Escherichia coli O157:H7, Salmonella spp.and Listeria monocytogenes.All samples were negative for Listeria monocytogenes and Escherichia coli O157:H7.Furthermore Salmonella spp. was detected on four carcasses.Table 1 shows the EU bacterial performance criteria for lamb carcass surfaces.On the other hand, Table 2 shows the result of TMCs and ECs which are indicators of carcass surface hygiene.EU 2001/471/EC requires for microbiological data to be obtained from the carcasses before chilling using an excision or swabbing method, with a view to determine the hygiene status within HACCP.According to the decision performance criteria, the TMCs and the ECs should be performed Š15¹.But no pathogen performance standards.However red meat is a significant source of bacteria which frequently cause foodborne illnesses in human.
A major survey for E. coli O157:H7, Listeria monocytogenes and Salmonella spp. on beef carcasses in Northern Ireland was studied.Only Salmonella spp. was isolated from three carcasses of 780, compared with the present survey, four carcasses of 100 but in a British survey of cattle carcasses (n=29), Listeria monocytogenes was found 7% positive Š10¹.In another study in the UK, 1500 carcasses were analysed and E. coli O157:H7 was isolated from 21 (1.4%) carcasses Š3¹.In France, E. coli O157:H7 was present in 1 (0.4%) of 225 carcasses Š7¹.E. coli O157:H7 was not isolated from carcasses in the Netherlands Š8¹, in Germany, in the USA, and in Turkey Š6¹.
At the same time, studies for determining the acceptability of carcass hygiene have been conducted some time ago.In New Zealand, 772 lamb carcasses were analysed and had a mean TMC of 3.35/cm 2 , while in Canada, another study found that sheep carcasses had log 10 TMC/cm 2 at the shoulder, loin and leg of 2.81; 2.80 and 2.56 respectively Š19¹.In South Australian, Phillips et al.Š7¹, sampled 917 carcasses and had a mean TMC of 3.54/cm 2 , EC of 0.16/cm 2 , compared with the present survey of 4.18-5.95and 1.60-2.30CFU/cm 2 respectively.
In conclusion, the main sources of the contamination for the red meat are microorganism on the hides.During the evisceration and dressing processes, they are transfered to the carcass surfaces directly and indirectly.Also, the contamination can be spread from the contaminated carcasses to other carcasses on