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5 . 1 T h e m i c r o b i o l o g i c a l q u a l i t y ( i n t e r m o f E . c o l i ) o f
f r e s h b r o i l e r m e a t i n B o g o r
Recovery rate of E. coli was 87.5% of total samples in this study, resulting in a high number of isolates. In general, concentration of E. coli significantly exceeded the limit as set in the Indonesian National Standard (SNI: 01-6366-2000) (P<0.05). The Indonesian National Standard (SNI: 01-6366-2000), accepted E. coli as an indicator of microbiological quality of poultry meat with a maximum permissible level of presumptive numbers of E. coli as 50 MPN/g in fresh or frozen meats. The recovery rate of E. coli from this study was much higher than recovery rate found in a study conducted by Aryanti et al. (2007), which reported a recovery rate of 75.68% from poulty meat. Difference in choice of samples for bacteriological examination might have resulted into the high recovery rate of E. coli in our study. This can be further affirmed by Mead (2007b) who suggested that skin maceration normally had high recovery rate of microorganisms and was the “gold standard” for detection or enumeration of organisms present in poultry carcass. Concerning antimicrobial resistance of E. coli, Persoons et al. (2010) stated that skin sample can give a better indicator for the resistance risk posed to consumers, but it is not a good predictor for E. coli resistance level in primary production. Many factors during the slaughtering, storage, transport, and processing of meat can contribute to contamination. E. coli can occupy multiple niches (Levy, 1997). E. coli is routinely shed into the environment. The contamination of meats by E. coli occurs most often during slaughter (Bhunia, 2008). These organisms can also be transmitted between humans, animals, the environment, and other food along the processing line (Meng and Schroeder, 2007). In this study, we found that most of the broilers were slaughtered in small scale slaughterhouses. Since these slaughterhouses used unhygienic practices, it is conceivable that there was a higher possibility of cross contamination. Aryanti et al. (2007) reported that the contamination of food of animal origin in Indonesia by E. coli resulted from unhygienic practices along the processing line. In order to reduce the amount of food contamination, the improvement of hygienic practices was highly recommended. 5 . 2 A n t i m i c r o b i a l r e s i s t a n c e o f E . c o l i i s o l a t e d f r o m
s e c t o r 3 f r e s h b r o i l e r m e a t i n B o g o r
In total 402 isolates E. coli were analyzed, and variety of combinations of antimicrobial resistance pattern among isolates from the same sample has been found. There are many possible reasons for the variation in antimicrobial resistance pattern found in the E. coli samples. It is possible that some isolates of E. coli originated from sources outside of farms. The transfer of resistant bacteria due to ecological factors such as the presence of other farm animals, rodents, pets, or personnel/workers/sellers is also a possible cause of the variation in antimicrobial resistance pattern (Smith et The highest prevalence of resistance in E. coli was found for the most commonly used poultry antimicrobials, which are tetracycline, erythromycin, ampicillin, nalidixid acid, enrofloxacin, and trimethoprim-sulfamethoxazole. A similar result was also reported by Poernomo et al. (1992), who found a high prevalence of resistance to tetracycline, erythromycin, ampicilin, and trimethoprim- sulfamethoxazole in E. coli isolated from poultry farms in the area of West Java. High accessibility to antimicrobial drugs without the need for prescription, which is common in West Java, may lead to an increase amount of antimicrobial resistance (Murdiati and Bahri, 1991). The cheap cost of tetracycline ascompared to other permitted antimicrobial feed additives (Appendix 4) directs the choice of tetracycline as feed additives in poultry in Indonesia. This high selection pressure can be the reason behind the high prevalence of resistance to tetracycline in E. coli (Murdiati and Bahri, 1991). Commercially available feed containing multiple antimicrobials can also contribute to the increasing amount of resistance (Furtula et al., 2010). Brady and Katz (1992) stated that about 80% of commercial poultry animals have been fed by at least one antimicrobial substance during their life time. Routine use of antimicrobials in food animals for growth promotion constitutes a serious public health concern, especially in the case where the same classes of antimicrobials are being used in humans (Wegener, 2003). Many studies have mentioned that the use of antimicrobial feed additives in farms is major factor driving the emergence of antimicrobial resistance (Cohen, 1992; Silbergeld et al., 2009). Based on economic analysis point of view Silbergeld et al. (2009) had concluded that, there is only little economic benefit from using antimicrobials as feed additives, and that equivalent improvements in growth and feed consumption can be achieved by improved hygiene. In comparison to another study, the frequency of E. coli resistance against chloramphenicol was much lower in our study. Poernomo et al. (1992) reported that 26.6% of E. coli isolated from colibacillosis (colisepticaemia) cases in poultry from West Java were resistant to chloramphenicol. Resistant against chloramphenicol and cephalothin was not expected as both antimicrobials are prohibited for use in poultry. The illegal use of these antimicrobials in poultry may be one of the factors causing the persistence of resistance in poultry isolates of E. coli. It might also be possible due to contamination of the meats by E. coli from other sources having selection pressure of chloramphenicol and cephalothin. Smith et al. (2007) on contrary reported that antimicrobial resistance pattern in E. coli isolated from broiler under experimental condition were not correlated with pattern of antimicrobial usage. Moreover, they also stated that, majority of multi-resistant phenotypes are obtained by the acquisition of mobile genetic materials, and it may provide resistance to an entire class of antimicrobials, such phenomena called as co-selection. These events have been detected frequently in resistant E. coli isolated from consumer meat products in Norway by Sunde & Norstrom (2006). The Australian Joint Expert Advisory Committee on Antibiotic Resistance (JETACAR) mentioned in their reports in 1999 that, a single mutation in some bacteria can cause resistance to multiple antibiotics such as tetracycline, chloramphenicol, trimethoprim, and some penicillin groups. The resistance appears to be due to a complex set of changes that alters the permeability of the cells, in particular, pumping these antibiotics out of the cell (efflux system). A similar study in Vietnam has been reported by Van et al. (2008). The results demonstrated that high single and multiple resistances to antimicrobials in E. coli isolated from fresh chicken meats were found. Comparing to our study, their results were much higher with regard to resistance of antimicrobials in E. coli isolates against tetracycline (84.2%), ampicillin (84.2%), gentamycine (47.4%), enrofloxacin (63.2%), nalidixic acid (64.4%), and chloramphenicol (57.9%). Higher multiple resistances of antimicrobial in E. coli were also found which amount to 89.5% of isolates resistant to at least three different antimicrobials. Other studies of antimicrobial resistances in E. coli isolated from broiler poultry in Asian region have been reported. In Malaysia, Apun et al. (2008) has reported a high degree of resistance of antimicrobials in E. coli isolated from broiler chicken. E. coli isolates were found much more resistance against chloramphenicol (46.43%), tetracycline (95.86%), cephalotin (14.29%), nalidixic acid (64.29%), and sulphamethoxazole-trimetrhoprim (82.14%). High multiple resistances in E. coli isolates were also mentioned, 85.72% resistance was found against more than three antimicrobial agents in broiler chicken. In India, Sharada et al. (2010) reported high resistant of E. coli isolates against chloramphenicol (16.92%), tetracycline (83.08%), erythromycin (94.19%), and gentamycin (40.00%). However, the prevalence of antimicrobial resistance differs widely among countries. These differences might be explained by differences in the degree of antimicrobial use, geographical differences, and variations in poultry production systems (Bywater et al., 2004). In the last decade, the frequency and spectrum of antimicrobial resistant bacteria infections has increased in both hospital and community (Byarugaba, 2004). Some reports mentioned that antimicrobial resistance among commensal E. coli isolated from community and hospitalized patients has emerged in Indonesia (Lestari et al., 2008; Refdanita et al., 2004). A high prevalence of resistance for chloramphenicol, trimethoprim-sulfamethoxazole, ampicillin, and tetracycline was observed among E. coli isolated from hospitalized patients. Lestari et al. (2008) also mentioned that the E. coli resistance rate in healthy persons discharged from the hospital were significantly higher than patients being admitted in the hospital. Silbergeld et al. (2009) mentioned that because of large size of the animal reservoir of resistance which includes consumer meats in poultry, the antimicrobials used in agricultural may generated a greater range of resistance, and it may result in a larger reservoir of non-hospitalized populations carrying antimicrobial resistance in term of pathogen and non pathogen bacteria, as well as transposable resistance genes. Concerning antimicrobial resistance, commensal E. coli has capacity to be a major threat for human consumers significantly. Commensal E. coli may serve as a reservoir of potential antimicrobial resistance genes in the environment, where the resistance may be transferred to other commensal or pathogenic bacteria (Angulo et al., 2004). Food contaminated with resistant commensal E. coli, which possibly carry resistance genes, may transfer the genes to other pathogenic bacteria of human clinical significance (Bester & Essack, 2010). Bacteria of animal origin possibly spread to food products during slaughter and further processing, which has been extensively documented for conventional foodborne pathogens, such as Salmonella, Campylobacter, and E. coli (Wegener, 2003; Bester & Essack, 2010). However, the treatment of pathogenic organism on farms may increase the likelihood of selective pressure in commensal E. coli (Bester & Essack, 2010). Intensification and commercialization of poultry production can be associated with the widespread use of antimicrobial substances in poultry (Soeripto, 1996) which can lead to high prevalence of resistance in gut commensal in poultry. The high number of multi drug resistant E. coli isolates raises questions about the control of antimicrobials use, management practices in the slaughter house and farm, and ultimately the safety of food. The indication of multiple antimicrobial substances used in the farms must not be economically efficient. Practically, the minimal biosecurity measures would be compensated by using antimicrobial substances to control bacterial infection. Thus, prudent use of antimicrobials should no way result in antimicrobials used on farms with poor management practices. The intervention strategies used for controlling antimicrobials use on farms with low to minimal biosecurity level should be reconsidered. It is required to set up a monitoring and surveillance program, and improve farming practices in order to reduce the transmission of antimicrobial resistance genes and thereby minimize the likelihood of horizontal gene transfers of these antimicrobial resistance genes to other microbes in the food chain. Training of consumers and food handlers on safe food handling and proper cooking are therefore important to reduce or eliminate the risk of antimicrobial resistance and pathogenic bacteria originating from raw foods. Additionally, it is recommended that antimicrobial usage regulations in animal feed must be strongly enforced. Further studies are also required to get more information as commensal E. coli can serve as a reservoir of resistance genes, determining genotypic patterns in E. coli may help us to illustrate the potential risks posed to

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