Study was conducted to determine the prevalence of Candida albicans in raw chicken and mutton meat samples sold in open meat markets of Kolkata city of West Bengal. A total of 200 meat samples, chicken 100 and mutton 100 were collected randomly from 5 different zones of Kolkata- Central, East, West, North and South. In the current study, prevalence of Candida albicans was 80%. Out of 200 samples examined, Candida albicans was isolated from 160 samples, of which 83 chicken samples and 77 mutton samples were found positive for Candida albicans infection. The result of the study indicates that load of Candida albicans in meat samples of Kolkata city is on higher side due to improper and faulty storage of raw meat, and consumption of under-processed/undercooked meat possess a possible health risk for consumers.
Chicken and mutton meats are amongst most consumed meat in Kolkata city of West Bengal as compared to other conventional meat. Raw meat is an important and probably the major source of human food borne infection. Food-borne diseases are responsible for majority of illness and death around the world particularly in developing countries (Guerrant et al., 1990). Foods including those of animal origin are most important vehicle that helps in transmitting pathogenic micro-organisms to human (Varnam, 1991). WHO state that illness due to contaminated food is perhaps the most widespread health problem and an important cause of reduced economic productivity (Käferstein, 2003). Candida albicans is the most common species causing human infections (Vazquez et al., 2002). Candida Species have been often considered but infrequently documented as a credible source of diarrhoea. Candida albicans is one of the most prevalent fungal infection (Martins et al., 2014). Candida albicans is an ovoid or spherical budding cell which produces pseudo mycelia both in tissues and in cultures. It is diploid fungus that grows both as yeast and filamentous cells and a causal agent of opportunistic oral and genital infections in humans (Ryan and Ray, 2004; d’Enfert and Hube, 2007) and also associated with food borne diarrhoea. Candida spp. has been involved in the causation of chronic diarrhea in HIV infected patient (Theresa et al., 2002). High prevalent of Candida species, especially Candida albicans in the environment has been reported (Answar et al., 2012). Meat is generally eaten cooked, but in some traditional recipes of India meat is eaten raw or is partially cooked. Meat tissues get contamination during the various stages of slaughter and transportation (Ercolini et al., 2006). Contaminated raw meat is one of the main sources of food borne illness (Bhandare et al., 2007; Podpecan et al., 2007). It is estimated that, hardly 5 per cent of the poultry meat produced in India is from organized processing units whereas; the rest is from unorganized sector (retail shops) where due to poor hygiene there is ample scope for contamination (Kumar et al., 2001). The present study provides a comprehensive report on the prevalence of Candida albicans in raw chicken and mutton meat samples of Kolkata city.
Materials and Methods
A total of 200 samples, 100 each of raw chicken meat and raw mutton meat were collected from five different zones of Kolkata city of West Bengal. The samples were collected in the morning hours and in cool conditions. Samples were collected in sterile container and transported in ice-packed thermocol bag at a temperature of about 4 to 8°C. Samples were processed on the same day under aseptic conditions. Samples were cut into smaller pieces using sterile knife and mixed properly with normal saline. To ensure proper mixing of meat with Normal saline, vortex machine was used and mixing was carried out for 5-10 minutes.
Isolation of Candida albicans
After uniform mixing, a loopful of inoculum streaked onto Sabouraud agar aseptically. Sabouraud agar contains peptones, ideal to cultivate dermatophytes and other types of fungi. The 5.6 pH of traditional Sabouraud agar formulation inhibits bacterial growth and allows only fungal growth.
Sabouraud Dextrose Agar (SDA) is a modification of dextrose agar. The prepared inoculum was inoculated onto SDA slant aseptically and incubated at 30°C for 7-10 days. Confirmation was done based on colony characteristics, as yeasts grow creamy to white colonies whereas molds grew as filamentous colonies of various colors.
Fig.1: Sabouraud Dextrose Agar (SDA) slant media showing growth of Candida albicans
Germ test is a screening test and was done to differentiate Candida albicans from other yeasts. Small colony of yeasts was collected from culture media and putted into small tube containing sheep serum and incubated it for 2-4 hours, and examined for germ tubes under microscope. Germ tubes appear as short, tube-like structures with no constriction at the junction with the yeast cell wall indicates Candida albicans.
Results and Discussion
In the present study, out of a total of 200 meat samples examined, 160 (80%) were found positive for Candida albicans. Candida albicans was detected from 83% of raw chicken & 77% of mutton meat samples examined. The prevalence of Candida albicans isolated from examined raw meat samples were summarized in Table 1.
Table 1: Prevalence of Candida albicans among chicken and mutton meat samples
|Nature of Samples||Total Positive Cases||Central Kolkata||East Kolkata||West Kolkata||North Kolkata||South Kolkata|
|Mutton ( n=100)||77||15||19||16||13||14|
|Total = 200||160||32||35||33||32||28|
Candida albicans were isolated from all five zones of Kolkata city under study namely East, West, North, South, and Central Kolkata. Prevalence of Candida albicans was higher in North Kolkata in chicken samples, while in mutton samples East Kolkata seemed highly contaminated. Candida albicans contamination was on higher side in chicken samples and the same depicted Table 1 and 2.
Table 2: Percentage of Candida albicans according to zones of Kolkata, %
|Nature of Samples||Positive cases||Central||East||West||North||South|
|Mutton ( n=100)||38.5||7.5||9.5||8||6.5||7|
|TOTAL = 200||80||16||17.5||16.5||16||14|
Probable reason of higher prevalence may be due to unhygienic handling of raw meat samples and higher roadside meat shops having less access to pure water to wash carcass properly. A month wise study on overall prevalence of Candida albicans in raw meat samples were summarized in Table 3, 4. July month (85%) had higher prevalence of overall contamination of meat followed by December (82.5%), and lower prevalence was seen in the month of September. Different meat cuts/parts were considered in the study. Parts of chicken meat like thigh, breast and wings were tested for the presence of Candida albicans, while thigh, groin and neck cuts of mutton were considered for the study.
Table 3: Prevalence of Candida albicans according to months of sample collection
|Month||Total Samples Examined||No. of Samples Positive||% of Positive Samples|
Table 4: Month wise prevalence of Candida albicans in chicken and mutton meat samples
|Collection Month||No. of Sample Tested||Chicken Sample Tested||Mutton Sample Tested|
|No. of samples||Positive||No. of Samples||Positive|
In both the meat samples, thigh portion of meat were more contaminated than other parts. Wings portion of chicken meat and neck cuts of mutton meat were comparatively less contaminated than rest of the examined parts and presented in Table 5.
Table 5: Distribution of Candida albicans among different meat cuts/parts of chicken and mutton
|Meat Cuts/Parts of Chicken||No. of Samples Examined||No. of Samples Positive (%)|
|Meat Cuts/Parts of Mutton|
The higher prevalence in the present study might be due to cross contamination during manual skinning, evisceration and processing in the butcher shops. Candida species were also readily isolated from the tables where meat carcasses are displayed (Olorode and Okpokwasli, 2012). The present study evaluates that most of the retail shops do not operate in a safe and sanitized environment.
Candida albicans is opportunistic pathogen of humans. In the present study, Candida albicans showed overall prevalence of 80%, including chicken 83%, and mutton 77%. The result of current study was supported by some earlier findings. One such study (Viljoen et al., 1998), reported that the prevalence of Candida albicans in chicken meat was 80%. Another study which was conducted at north eastern states of India, (Joshi and Saikia, 2010) found 80% prevalence in chicken meat samples. Thanigaivel and Anandhan (2015) reported isolation of Candida albicans from 5% of raw chicken and mutton meat examined from different market places in and around Chennai. There were limited works on isolation of Candida albicans from meat samples. The open meat markets from where the meat collected were mostly unhygienic. No proper drainage systems were present in most of the areas. Most of the markets were open markets with no proper pucca shops. A high contamination was observed in meat shops as the same cutting blocks and knives were used (Satin, 2002). These conditions provide favorable environment for cross-contamination, growth and multiplication of different microorganisms considering the suitable temperature, humidity and supply of nutrients from the meat samples themselves. This has a definite implication from the public health point of view. Promotion of awareness and importance of hygienic practices among animal handlers, butchers, public, etc., is recommended. Although a very few modern poultry processing plants have been established, majority of the consumers purchase meat from the roadside shops or small retailers where chickens are being slaughtered and dressed in unhygienic condition in their presence (Das and Biswas, 2003). It is observed that daily unsold raw meat was not stored properly by the butchers for further marketing by next day, which is responsible of growth of Candida albicans in raw chicken and mutton meat. It is concluded that contamination of raw chicken and mutton meat should be prevented during handling, slaughter and processing to protect the public from infections and diseases.
The present study concludes that raw chicken and mutton meat sold in open meat market of Kolkata city harbors Candida albicans and those humans consuming contaminated meats are at a risk of contracting Candida albicans infections, especially immunocompromised individuals and children, where dearth of proper sanitation in the market places prevails. The possible causes of this higher prevalence are improper and faulty storage of unsold raw meat for longer period of time and use of contaminated water for washing meat. This suggest suitable control measures like hygienic practice of handling and storage of raw meat and awareness campaign related to lack of proper scientific knowledge and health education amongst meat handlers and butchers.