Fresh vegetables have become associated with outbreaks caused by Escherichia coli O157:H7 (EcO157). Between 1995–2006, 22 produce outbreaks were documented in the United States, with nearly half traced to lettuce or spinach grown in California. Outbreaks between 2002 and 2006 induced investigations of possible sources of pre-harvest contamination on implicated farms in the Salinas and San Juan valleys of California, and a survey of the Salinas watershed. EcO157 was isolated at least once from 15 of 22 different watershed sites over a 19 month period. The incidence of EcO157 increased significantly when heavy rain caused an increased flow rate in the rivers. Approximately 1000 EcO157 isolates obtained from cultures of>100 individual samples were typed using Multi-Locus Variable-number-tandem-repeat Analysis (MLVA) to assist in identifying potential fate and transport of EcO157 in this region. A subset of these environmental isolates were typed by Pulse Field Gel Electrophoresis (PFGE) in order to make comparisons with human clinical isolates associated with outbreak and sporadic illness. Recurrence of identical and closely related EcO157 strains from specific locations in the Salinas and San Juan valleys suggests that transport of the pathogen is usually restricted. In a preliminary study, EcO157 was detected in water at multiple locations in a low-flow creek only within 135 meters of a point source. However, possible transport up to 32 km was detected during periods of higher water flow associated with flooding. During the 2006 baby spinach outbreak investigation, transport was also detected where water was unlikely to be involved. These results indicate that contamination of the environment is a dynamic process involving multiple sources and methods of transport. Intensive studies of the sources, incidence, fate and transport of EcO157 near produce production are required to determine the mechanisms of pre-harvest contamination and potential risks for human illness.

/pdf/incidence-and-tracking-of-escherichia-coli-o157-h7-in-a-iz0ppnon32.pdf

Incidence and Tracking of Escherichia coli O157:H7 in a Major Produce Production Region in California

Prevalence and concentration of verocytotoxigenic Escherichia coli, Salmonella enterica and Listeria monocytogenes in the beef production chain: a review.

Infection with Campylobacter jejuni is now considered to be the most common cause of acute bacterial gastroenteritis in humans worldwide. It occurs more frequently than infections caused by Salmonella species, Shigella species, or Escherichia coli O157:H7. Although C. jejuni is also recognized for its association with serious post-infection neurological complications, most patients with C. jejuni infections have a self-limited illness. Nevertheless, a substantial proportion of these infections are treated with antibiotics. These include severe and prolonged cases of enteritis, infections in immune-suppressed patients, septicaemia and other extra-intestinal infections. Under these circumstances, erythromycin is often recommended as the drug of first choice. However, erythromycin-resistant Campylobacter have emerged during therapy with macrolides. Moreover, the widespread use of macrolides, including erythromycin, in veterinary medicine has accelerated this resistance trend. Several countries including Canada, Japan and Finland have reported C. jejuni isolates with low and stable rates of macrolide resistance. In contrast, the increasing level of macrolide resistance in C. jejuni is becoming a major public health concern in other parts of the world such as the United States, Europe and Taiwan. Macrolide resistance in Campylobacter is mainly associated with point mutation(s) occurring in the peptidyl-encoding region in domain V of the 23S rRNA gene, the target of macrolides. Several rapid and practical techniques have recently been developed for the identification of macrolide-resistant isolates of C. jejuni. The aim of this mini-review is to give an overview of the worldwide distribution of macrolide resistance in C. jejuni and Campylobacter coli as well as its possible association with the massive use of these agents in food animals. Mechanisms implicated in macrolide resistance in C. jejuni and also techniques that have been developed for the efficient detection of macrolide-associated mutation(s) will be discussed in detail.

/pdf/macrolide-resistance-in-campylobacter-jejuni-and-1ivf383mr2.pdf

Macrolide resistance in Campylobacter jejuni and Campylobacter coli

Campylobacter jejuni is a major cause of food-borne gastroenteritis worldwide. While mortality is low, morbidity imparted by post-infectious sequelae such as Guillain-Barre syndrome, Reiter syndrome/reactive arthritis and irritable bowel syndrome is significant. In addition, the economic cost is high due to lost productivity. Food animals, particularly poultry, are the main reservoirs of C. jejuni. The over-use of antibiotics in the human population and in animal husbandry has led to an increase in antibiotic-resistant infections, particularly with fluoroquinolones. This is problematic because C. jejuni gastroenteritis is clinically indistinguishable from that caused by other bacterial pathogens, and such illnesses are usually treated empirically with fluoroquinolones. Since C. jejuni is naturally transformable, acquisition of additional genes imparting antibiotic resistance is likely. Therefore, an understanding of the antibiotic resistance mechanisms in C. jejuni is needed to provide proper therapy both to the veterinary and human populations.

https://www.tandfonline.com/doi/pdf/10.4161/viru.23753

Resistance mechanisms in Campylobacter jejuni.

Current trends in sample preparation for growth promoter and veterinary drug residue analysis.

Analysis on residues of estrogens, gestagens and androgens in kidney fat and meat with gas chromatography-tandem mass spectrometry.

Identification of "unknown analytes" in injection sites: a semi-quantitative interpretation

Since 1997, the Belgian zoonosis surveillance program has assessed the contamination with Salmonella in cattle, pig, poultry, rabbit and fish. The number of samples was approximately 120 in 1997, 150 in 1998 and 1999 and 310 in 2000 and 2001 for each matrix. Between 1997 and 1999, the analysed sample amount has been adjusted to obtain semi-quantitative results and determine the appropriate amount to investigate for each matrix. The matrixes investigated and the sample size investigated are shown in table 1. The detection of Salmonella has been carried out with the official method from the Ministry of Public Health (SP-VG M002). Briefly, this method consist of a pre-enrichment into buffered peptone water (16-18h at 37°C) followed by a culture of 100μl onto a semisolid selective enrichment media (Diassalm incubated for 24h at 42°C). From typical migration zones, a loopful was streaked onto xylose lysine desoxycholate agar (XLD incubated for 24h at 37°C). Suspicious-looking colonies were confirmed by biochemical tests. The isolates were serotyped, lysotyped, and the antibiotic resistance assessed (results not shown). Introduction Salmonella is among the most important meat pathogen worldwide. The prevalence and the level of contamination are essential for an efficient risk assessment program but all the different serovars do not have the same virulence potentiality.

exposure Assessment of Salmonella in animal foods in belgium

Escherichia coli O157 prevalence in foods from animal origin in Belgium

Since 1998, the Belgian surveillance program has assessed the contamination with E. coli of meat from beef, pork, layers, broilers, turkeys and fish. The following matrixes were sampled for E. coli: swabs of: beef and calf carcasses (4 zones on a half beef carcass for about 400 cm2 in 1998 and 1600cm2 since 1999), pork carcasses (4 zones on a half pork carcass for about 600 cm2) minced meat of beef, retail cuts and minced meat of pork, skin and boneless breast of broilers, skin of layers and turkeys and, in 2000 meat products (ham, pâté, salami). In 2001, the contamination level of beef and pork carcasses, and meat products with Enterobacteriaceae has been assessed. In 2001, the total plate count was also realised from beef and pork carcasses. The E. coli count (in cfu/g or cm2) has been realised with the AFNOR validated SDP-07/1-07/93 using the chromogenic Rapid E. coli 2 medium (Bio-Rad) with an incubation during 24h at 44°C. The total plate count followed the NF-V-08-051 method (PCA at 30°C during 48-72h) and the enumeration of Enterobacteriaceae was realised using the NF-V-08-054 method (VRBG at 30°C during 24h). Introduction The faecal contamination is likely the main source of potential human pathogens including Salmonella, Campylobacter and enterohemorrhagic Escherichia coli on animal carcasses and in meat. Leakage from the gastrointestinal tract or contact with the animal skin could cause widespread contamination. In warm-blooded animals, the best indication of faecal contamination is Escherichia coli. This microorganism is widely present in the gastrointestinal tract and survives under refrigerated conditions but temperatures below 7°C prevent its growth. The USDA has chosen E. coli as indicator of faecal contamination and the enumeration of E. coli has to be done mandatory for all industries commercialising meat in United States of America. In its Decision of 8 June 2001 (2001/471/EC), the European Commission lays down the Enterobacteriaceae and total viable counts as regular checks on general hygiene in establishments producing and marketing fresh meat. However, after establishing appropriate criteria, E. coli counts may be used instead of Enterobacteriaceae counts. The Belgian meat surveillance between 1998 and 2001 has allowed the evaluation of the sampling method and has proposed criteria for E. coli, Enterobacteriaceae and total plate counts.

/pdf/assessment-of-microbiological-criteria-for-regular-checks-of-dbbp5jia6k.pdf

Assessment of microbiological criteria for regular checks of faecal contamination and general hygiene in Belgian establishments producing meat

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