BACTERIOLOGICAL EVALUATION OF FROZEN QUAILS SOLD IN MARKETS

Assiut Vet. Med. J. Vol. 52 No. 111 October 2006

Animal Health Research Institute, Port Said Laboratory for Food Hygiene.

BACTERIOLOGICAL EVALUATION OF FROZEN QUAILS SOLD IN MARKETS

(With 3 Tables)

By ZIENAB I. SOLIMAN and AZZA A. EL-TABIY

(Received at 16/9/2006)

التقييم البکتريولوجي للسمان المجمد المباع في الأسواق

زینب إبراهيم سليمان،عزة على حسين التابعي انتشرت في الآونة الأخيرة مزارع السمان وزاد الإقبال على استهلاک لحومها. ويتميز السمان بطعمه المحبب وطراوته ورخص ثمنه واحتوائه على نسبة قليلة من الکولسترول مما يجعله مصدر صحي ومهم للبروتين يفوق کثيرا من الطيور الأخرى. قد تتعرض لحوم السمان أثناء الذبح والتجهيز للتلوث البکتيري لذلک أجريت هذه الدراسة لتقييم الحالة البکترية للسمان المجمد المطروح في الأسواق في محافظة بورسعيد. تم تجميع مائة وخمسون عينة من السمان المجمد وتم تقيمها من حيث العد الکلى البکتيري Aerobic Colony Count (ACC) والعدد الکلي لکل من الميکروبات المعوية والذهبي العنقودي. کذلک تم فحص العينات لوجود ميکروبات سيدوموناس ایرجينوزا وجنس سيدوموناس، کامبيلوباکتر، الذهبي العنقودي، السالمونيله، الإشريشيا القولونية نوعH7:0157 والإشريشيا القولونية. أسفرت النتائج على أن معظم العينات (۹۳٫۳%) تحتوي على عدد کلى بکتيري اقل من 10 لکل جرام کذلک کان متوسط العدد الکلي للميکروبات المعوي والذهبي العنقودي في الحدود المسموح به (اقل من 10 لکل جرام). کما وجد أن نسبة ۹۱٫۳ % من العينات ملوثة بمیکروب سيدوموناس وتم عزل سيدوموناس ایرجینوزا من ۲۰ % من العينات. کذلک أظهرت النتائج عن وجود کلا من ميکروبات الإشريشيا القولونية، السالمونيله والذهبي العنقودي بنسبة

۲۰,3

% ، ۱۸ % ، ۲۰ % على التوالي ولم يتم عزل أي من ميکروبات کامبيلوباکتر والإشريشيا القولونية نوع H7:0157 من العينات التي تم فحصها. کذلک تم توضيح الأهمية الصحية ومدى خطورة الميکروبات المعزولة على صحة المستهلک وکذلک بعض الاشتراطات الصحية الواجب توافرها.

SUMMARY

One hundred and fifty samples of frozen quails were collected from markets in Port Said Governorate for microbiological analysis to assure their quality and safety. The samples were screened for aerobic colony count (ACC), Enterobacteriaceae and Staphylococcus aureus counts and

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pathogen including Pseudomonas spp., Pseudomonas aeruginosa. E.coli, E. coli O157:H7, Salmonella. S. aureus and Campylobacter. Bacteriological analysis revealed that in 93.3% of the investigated frozen quails samples, the ACC was < 10 cfu/g. The mean values of aerobic plate count, Enterobacteriaceae and S. aureus counts were 5.1x 10'

1.1x102, 1.2x 103 3x 102 and 0.3x 102 cfu/g, respectively. Pseudomonas spp. were detected in 61.3% and Pseudomonas aeruginosa in 20% of samples. E. coli was detected in 25.3% of samples, but none was serotype 0157:H7. Salmonella was detected in 27 (18%). S. aureus was isolated from 30 (20%). Campylobacter was not isolated from any of the investigated samples. The public health aspects for the estimated and isolated criteria were outlined as well as suggested hygienic measures were discussed.

Key words: Quail carcases, Enterobacteriaceae, Campylobacter, S. aureus

INTRODUCTION

In recent years quail meat has been gaining in popularity among consumers. Many quail farms have been established in Egypt both for egg and meat production. Distinct characteristics include rapid growth, marketed for consumption at 5- 6 weeks of age and high disease resistance, enabling quail industries to be accepted in Egypt.

Microbial food safety is an increasing public health concern worldwide. The major cause of foodborne disease is microbiological (Wolf, 1992). It has been estimated that the risk of foodborne disease and malnutrition is a thousand times greater than illness caused by pesticides or additives (Grose, 1988; Wheelock, 1989). Contaminated raw or undercooked poultry and red meats are particularly important in transmitting foodborne pathogens. Poultry meat can be contaminated with a variety of microorganisms, including those capable of spoiling the product during chill storage like Pseudomonas spp. (Arnaut-Rollier et al., 1999). Moreover, poultry are perceived to be responsible for significant amount of human illness because of the relatively high frequency of contamination of poultry with Salmonella spp. (Geornaras et al., 1995, Geilhausen et al., 1996; Uyttendaele et al., 1999 and Kessel et al., 2001), Campylobacter (Rosenquistc, et al., 2003) ,S. aureus (Geornaras et al., 1995; Khalifa and Nassar, 2001) and E.coli (Zhao et al., 2001) .As in case of chicken, quail meat can be contaminated with foodborne pathogens during slaughtering, defeathering, evisceration and other preparation processes.

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Freezing is an excellent way to preserve animal products such as meat, poultry, fish and shellfish. Freezing does not sterilize food, the extreme cold simply retards the growth of microorganisms and slows down the changes that affect quality or cause spoilage in food (Banwart, 1979). The quality and safety of the final product depends on how the product is handled before, during and after freezing. To ensure the continued growth and competitiveness of this industry, it is essential that quails meat quality and safety are maintained during production and processing. Assessment of the quality and safety of foods requires microbiological analysis. The objectives of this investigation were (1) to determine the microbiological quality of frozen quail and (2) to document the presence or absence of some pathogens in frozen quail meat.

MATERIALS and METHODS

Samples

One hundred and fifty samples of frozen quails collected from local retail supermarkets in Port Said Governorate were transferred in an icebox. Each carcass was left to defrost at 4°C for 6 hours. Microbiological quality analysis:

Twenty-five gm muscle meat with skin sampled randomly from different parts of each carcass were blended with 225 ml buffered peptone water (1%). Tenfold serial dilution in 0.1% sterile peptone water was prepared. Aerobic colony count (ACC), Enterobacteriaceae and S. aureus counts were carried out according to APHA (1992). Total plate count was determined using plate count agar, Enterobacteriaceae counts by Violet Red Bile Agar + 1% glucose and S. aureus counts on Baird Parker tellurite egg yolk agar (BPA). The characteristic black colonies of S. aureus with peripheral clearance zone on BPA were counted and typical isolates were tested for coagulase activity. Determination of Pseudomonas organisms:

Presence of Pseudomonas organisms was determined according the technique recommended by Anon (1986). Isolation and identification of Pseudomonas aeruginosa were carried out according to Quinn et al., (1994). Microbiological safety analysis:

Isolation and identification of E. coli, Salmonella, S. aureus and Campylobacter organisms were carried out according to the methods obtained by Food and Drug Administration (FDA, 1998).

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Identification of E. coli O157:H7:

Typical E. coli were identified serologically by slide agglutination test using diagnostic E. coli O antisera and H 7 antisera (Escherichia coli antisera, Denka Seiken Co., Ltd, Tokyo, Japan), following the manufacturer's specification.

RESULTS

Table 1: Statistical analytical results of bacterial counts,

Enterobacteriaceae and S. aureus in frozen quails samples (n= 150).

| Minimum Maximum Mean

SE Aerobic colony count <102 2.3x10C 5.1x103 1.1x102 Enterobacteriaceae

8x10 1.2x103 3x102 S. aureus

<102 1.5x10 0.3x102

1.2 <102= Non detectable level.

<102

Table 2: Frequency distribution of bacterial counts, Enterobacteriaceae

and S. aureus in frozen quails samples(n= 150).

ACC

Enterobacteriaceae

S. aureus

Frequency

range (cfu/g)

No. T

%

No.

%

No.1

%

80

53.3

120

98 18

20

10

12

34

<102 10-<103

30 10-<104

18 104 <10 12

>10

10 1 ACC : Aerobic colony count <102=Non detectable level.

65.3

12 22.6

0 0

20 0 0

80 6.7 13.3

0 0

6.7

0

Table 3: Incidence of the isolated bacteria from the examined frozen

quails samples (n= 150).

Organism

No. of positive samples % of positive samples Pseudomonas spp.

92

61.3 P. aeruginosa

30

20 E. coli

38

25.3 E. coli O157:H7

0 Salmonella spp.

27

18 S. aureus

30 Campylobacter spp.

0

0

20

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DISCUSSION

Quail meat have many advantages and superiority on the other species of poultry due to its low content of cholesterol and are considered as a valuable source of protein and minerals. The microbiological safety and quality of poultry meat are equally important to producers, retailers and consumers.

The total aerobic colony count, the Enterobacteriaceae and Staphylococcus aureus counting results obtained from 150 frozen quails samples collected from markets in Port Said were given in Tables (1 and 2). The achieved results revealed that, minimum, maximum and mean values of aerobic colony counts of frozen quails samples were <104 2.3x10° and 5.1x10*cfu/gm, respectively. Moreover, Table (2) indicated that 93.3% of the examined samples were within the permissible limi (10 cfu/gm) which obtained by the Egyptian Organization for Standardization and Quality Control (EOSQC, 1995). However, only 6.7 % of the examined frozen quails samples had countable numbers of total bacteria, ranged from 2 x10 to 1.2x10 cfu/gm. This may attributed to temperature abuse of the product prior to freezing or from poor sanitation in handling or processing and indicates that if it is subjected to temperature abuse, spoilage may occur in short time. The mean Enterobacteriaceae count of the examined samples was 1.2 x10 # 3x10 cfu/g with a minimum value <10%cfu/g and a maximum value 8x10°. Enterobacteriaceae counts in food samples have been used as indicators of hygiene and contamination after processing, satisfactory <100, acceptable 100-<104 and unsatisfactory >104 (Gilbert, et al., 2000). Accordingly, all examined samples are satisfactory and/or acceptable. With respect to S. aureus; minimum, maximum and mean values were <102,1.5x103 and 0.3x102 the maximum count of S. aureus recorded in investigated quails samples was 1.5 x10 cfu/gm, respectively (Table 1). The data obtained in Table (2) proved that 80% of the examined samples were contain S. aureus below the permissible limit (10'cfu/gm) which suggested by EOSQC, (1995), while only 20% of frozen quails samples were contained S. aureus exceeded the permissible limit.

Poultry meat can be contaminated with a variety of microorganisms, including those capable of spoiling the product during chill storage, and certain foodborne pathogens. When poultry meat is stored aerobically under chill conditions, the organisms that predominate are invariably Pseudomonas spp. (Arnaut- Rollier et al., 1999).

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The results of the present study revealed that Pseudomonas spp. were detected in 92 (61.3%) of the investigated frozen quails samples. The incidence of Pseudomonas aeruginosa was found to be 20% (Table 3). The genus Pseudomonas represents the most psychrotrophic bacteria and can be taken as indicator for keeping quality and a measure for spoilage of meat. These organisms are highly proteolytic and/ or strong lipolytic and lead to biological changes in composition of meat particularly at low temperature (Gill and Newton, 1982). Pseudomonas aeruginosa has the ability to cause spoilage of meat and leads to several outbreaks of food poisoning (Pererra et al., 1977). In this concern, Lukasova and Marz (1986) found that freezing at -18 °C reduced Pseudomonas aeruginosa count but did not results in complete reduction of the organism.

The presence of pathogenic organisms on foods (Salmonella spp, Campylobacter, Staphylococcus aureus and E. coli O157:H7) poses a food poisoning threat and following a number of recent high publicity food-related health scare (Mead, 2004).

Data in Table (3) showed that E. coli, Salmonella , and S. aureus were recovered at rate of 25.3 %, 18 % and 20 % from the examined samples, respectively. Neither Campylobacter nor E. coli O157:H7 were isolated in this study. Several other researchers have investigated the prevalence of many microorganisms that have public health significant in quails (Bottarelli et al., 1994, Mostafa, 1997, Abd- El-Wahab et al., 1998, Mossad et al., 2000 and Medani et al., 2002).

The rate of microbial contamination of retail frozen quails with E. coli in this study was 25.3%. The presence of E. coli and other Enterobacteriaceae in food samples most likely indicates fecal contamination (Aslam et al., 2003). The importance of E. coli as a cause of diarrhoeic disease has been increasingly recognized (Desmarchelier and Grau, 1997). All E. coli isolates identified in this study were negative for the presence of E. coli O157:H7. Several studies have shown that E. coli O157:H7 is present in retail meat products; mostly beef products (Samadpour et al., 1994). Despite the rarity of E. coli 0157 in poultry, an outbreak in the UK that associated with eating turkey roll was reported by Salmon et al. (1989).

In terms of bacteria contamination, Salmonella spp. remains the most important infective agent of foodborne disease. Isolation of Salmonella from 18 % of the examined samples was of concern. Most Salmonellas found on poultry meat are non-host-specific and are considered capable of causing human food poisoning. Salmonella

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a urouri feral spjamination or

WV).

nositive hirds at the time of slaughter have high numbers of organisms in

L their intestines as well as on the external sulas (10 feathers). Cross contamination during processing may also lead 10 increased prevalence of Salmonella in the finished products. Salmonellosis is a leading cause of enteric illness, with symptoms ranging from mild gastroenteritis to systemic illness such as septicemia and other longer-term conditions (Bryan and Doyle, 1995). A wide range of foods has been implicated in food-borne salmonellosis. However, as the disease is primarily zoonotic, foods of animal origin (in particular poultry) have been consistently implicated as the main sources of human salmonellosis (FAO/WHO, 2002).

Staphylococcus aureus is a ubiquitous organism in warm blooded animals and its presence in a low number in raw foods of animal origin is to be expected. The presence of S. aureus may be due to contamination of food, human being normally harbour S. aureus, the main reservoir is the nasal cavity. The organisms find their way to skin, air and dust, which may contaminate meat and may cause staphylococcal food poisoning (Forbes et al., 1998). Illness resulting from consumption of cooked poultry meat contaminated by S. aureus presents a risk due to the inactivation of competing microorganisms during cooking. Time and temperature abuse could allow growth of S. aureus that subsequently produce enterotoxin. (Ray, 2001). The production of enterotoxin (heat stable toxins) by S. aureus in food cause nausea, vomiting, retching, abdominal cramping and diarrhea in human (Gracey et al., 1999).

Campylobacter spp. are recognized as an important cause of foodborne diarrhea in humans. (Brieseman, 1990). Concern has been expressed about the potential for infection of this bacterium via raw poultry (Kramer et al., 2000). However, Campylobacter was not isolated in this study. The failure to isolate Campylobacter spp. may relate to lack of contamination with this organism. In addition Campylobacter spp. do not survive well at freezer temperatures (Moorhead and Dykes, 2002).

For food to be entirely safe from the microbiological viewpoint, it would need to be free from all pathogenic organisms. However, that this is not a realistic goal. There is still no economically viable means of eliminating foodborne pathogens in poultry-meat production because of the technological limitations in the process that can lead to cross contamination of the carcasses being processed. In the processing microbial hazards can be introduced into poultry meat or grow to potentially hazardous levels, through: direct contamination by food

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handlers

VULW

Wiensis, processing operations and the

processing environment. Human illness may follow from handling of raw meat, undercooking or mishandling of the cooked product. Bacterial growth during thawing may be particularly relevant for pathogens such as S. aureus that are likely of minimal concern at low levels but can cause serious disease if allowed to grow and produce toxins. To diminish contamination rates in retail quails, it is critical that risk reduction strategies are used throughout the food chain. These strategies include on-farm practices that reduce pathogen carriage; Controlled slaughter and handling processes may be helpful. Additionally, consumption of undercooked food and cross-contamination during food handling and preparation must be avoided to ensure food safety at home and in the food service industry.

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