DISTRIBUTION OF DIARRHEAGENIC ESCHERICHIA COLI FROM FOOD SAMPLES IN MALAYSIA Zulhainan Hamzah, Farah Wahida Zainal Abidin, Abd. Aziz Yahaya, Nuri Farita Abu Shahar, [email protected]
Yusoff, Punithavathi R.S. Maniam, Noor Afidah Abd. Majid and Mohamed Naim Abdul Kadir Ipoh Public Health Laboratory (IPHL), Ministry of Health Malaysia, Jalan Jelapang, 30020 Ipoh, Perak Darul Ridzuan, Malaysia ABSTRACT In this report, we have sucessfully serotyped a total of 252 Diarrheagenic Escherichia coli isolates from variety of food samples from 2005 through 2010. Among the Diarrheagenic E. coli isolates, Enterotoxigenic E. coli was identified as the most common (71.83%), followed by Enteropathogenic E. coli (13.5%), Enterohaemorrhagic E. coli (11.9%) and Enteroinvasive E. coli (2.8%). This study indicate that Enterotoxigenic E. coli was the most common Diarrheagenic E. coli strains isolated from food samples. INTRODUCTION Escherichia coli (E. coli) can be subdivided into pathological groups according to the main features of the induced disease. One of these pathogroups, commonly referred to as Diarrheagenic E. coli (DEC) includes E. coli strains which cause gastroenteritis in humans and animals. Diarrheagenic E. coli (DEC) pathotypes, in particular some strains of Verocytotoxic E. coli (VTEC), are pathogens of significant public health concern and have been the subject of epidemiological studies for some time. While there is significant data available on the VTEC pathotype such as Enterohaemorrhagic E. coli (EHEC), there remains a gap in knowledge surrounding the remaining pathotypes; such as Enteropathogenic E. coli (EPEC), Enterotoxinogenic E. coli (ETEC), Enteroinvasive E. coli (EIEC), Enteroaggregative E. coli (EAggEC) and Diffusely adherent E. coli (DAEC). In this report, we demonstrate the distribution for Diarrheagenic E. coli which includes ETEC, EPEC, EIEC and EHEC from food samples including foodstuffs associated with E. coli outbreaks, from January 2005 through December 2010.
Chart 1: E coli Serotyping 2005-2010 others 351 8.1%
Diarrheagenic E. coli 252 5.8%
Non Diarrheagenic E. coli 3740 86.1%
METHODS A total of 4,343 E. coli isolates were received from Makmal Kualiti dan Keselamatan Makanan (MKKM) throughout Malaysia from year 2005 to December 2010. All isolates were first sub-cultured and further tested with biochemical test for confirmation of E. coli. Serotyping were carried out according to the modified Kauffman serotyping scheme. All serotyping activities were carried out at Ipoh Public Health Laboratory (IPHL), as part of National Lab-Based Surveillance System for Infectious Diseases, Ministry of Health Malaysia.
Graf 1: The percentages of Diarrheagenic E coli (DEC) according to food sources
A total of 5.8% or 252 Diarrheagenic E. coli (DEC) isolates were successfully serotyped among the 4,343 E. coli isolates received from food samples at IPHL, while Non Diarrheagenic E. coli and contaminated isolates were 86.1% (3,740) and 8.1% (351), respectively (Chart 1). Diarrheagenic E. coli (DEC) strains were found higher in prepared food (e.g fried rice) followed by water related sources (e.g air perigi), beverages and processed food (Graf 1). Results also showed among the Diarrheagenic E. coli strains, Enterotoxigenic E. coli (ETEC) was identified as the most common strain (71.83%) found in food samples, followed by EPEC (13.5%), EHEC (11.9%) and EIEC (2.8%), as shown in Chart 2.
60 40 5%
0 prepared food
DISCUSSION Despite the large number of E. coli isolates received, the percentages of Diarrheagenic E. coli (DEC) strains isolated were still very low compared to Non Diarrheagenic E. Coli. This observation may indicates that most of food samples analysed were actually contaminated with harmless strains of E. coli. Nevertheless, the presence of DEC in food samples, have strongly highlighted the importance for people to be more cautious and selective with variety of foods available in the market or in restaurants in order to avoid any possible infections by DEC strains. In general, our analysis showed that distribution of DEC strains in Malaysia differs from those reported in other countries and seems to be related to different type of food products and reservoirs. In this report ETEC was the most common Diarrheagenic E. coli (DEC) strains isolated from food samples. Whereas, in European countries, VTEC (E. coli 0157) was found to be the most common followed by other strains that may occasionally present as a secondary contamination (Bolton et al., 2009). In relation to the recent outbreaks of E. coli 0104:H4 (EHEC) in Germany, Ipoh Public Health Laboratory recently, has been given the responsibility by Ministry of Health Malaysia (MOH) to perform the E. coli serotyping for all E. coli isolates related to the outbreaks, if any. Thus, Ipoh Public Health Laboratory (IPHL) has been recognized as the Centre of Excellence for E. coli in Malaysia.
Chart 2: Total distribution of ETEC, EPEC, EHEC and EIEC in food samples
Acknowledgement Makmal Kualiti dan Keselamatan Makanan (MKKM), KKM
EIEC 2.8% EPEC 13.5%