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Background: Gastrointestinal infections have been proposed to predict subsequent irritable bowel syndrome (IBS) but large-scale infectious events are rare and long-term data are missing., Methods: We identified 576 individuals with a Salmonella or Campylobacter infection between 2000 and 2009 that were followed by a short postal questionnaire asking for the presence of current symptoms in 2010. In case of agreement (n = 90), an extended postinfectious (PI)-IBS questionnaire was mailed including the Hospital Anxiety Depression Scale and the Patient Health Questionnaire., Key Results: A total of 189 patients reported back (36%); 98 had a Salmonella and 91 had a Campylobacter infection, of which 56 reported persistent symptoms (9.7% of the initial sample). Fifty-one patients returned the PI-IBS questionnaire. Of 48 patients with complete data, 15 reported no or mild symptoms of abdominal pain or discomfort while 17 had moderate and 16 severe symptoms. Twenty-two met Rome IBS criteria, 14 (29%) reported GI symptoms before the infection. Patients with moderate and/or severe PI-IBS symptoms were significantly more often females, were more often infected by Salmonella than by Campylobacter, had more severe symptoms during the initial infection, and had more often GI symptoms prior to the infection. They reported higher anxiety, depression, and somatisation scores, but were not different with respect to acute stool habits., Conclusions & Inferences: Nearly 10% of patients with an intestinal bacterial infection report postinfectious symptoms up to 10 years after the infectious event. They represent a clinically important population with high psychiatric comorbidity and somatic symptom burden., (© 2011 Blackwell Publishing Ltd.)

Aim: A species-specific nested polymerase chain reaction (PCR) assay was used to investigate the occurrence of Campylobacter gracilis and C. rectus in primary root canal infections., Methodology: Samples were collected from 57 single-rooted teeth with carious lesions, necrotic pulps and radiographic evidence of periradicular disease. Twenty-eight cases were diagnosed as chronic asymptomatic periradicular lesions, 12 cases as acute apical periodontitis, and 17 cases as acute periradicular abscess. DNA was extracted from the samples and initially amplified using universal 16S rDNA primers. A second round of amplification using the first PCR products was performed to specifically detect C. gracilis or C. rectus in the samples., Results: Campylobacter gracilis and C. rectus were, respectively, detected in 21.4 (6 of 28) and 30% (6 of 20) of the root canals associated with chronic asymptomatic periradicular lesions. Campylobacter gracilis was found in 16.7% (2 of 12) of the cases diagnosed as acute apical periodontitis, whilst C. rectus was found in 33.3% (two of six cases). In the abscessed cases, C. gracilis and C. rectus were detected in 23.5 (4 of 17) and 11.8% (2 of 17) of the cases, respectively. No association of these species with clinical symptoms was observed (P > 0.01) In general, species-specific nPCR allowed the detection of C. gracilis in 21.1% (12 of 57) and C. rectus in 23.3% (10 of 43)of the samples taken from primary endodontic infections., Conclusions: Findings confirmed the assertion that both C. gracilis and C. rectus participate in infections of endodontic origin and suggest a pathogenetic role with regard to periradicular diseases.

The genome analysis of the gastrointestinal pathogens Helicobacter and Campylobacter has stimulated a wealth of new research activities, which are presented every 2 years at the international conferences on Campylobacter, Helicobacter and Related Organisms (CHRO). Both organisms represent excellent models for the identification of new molecular mechanisms involved in pathogenesis, host response and physiological adaptation in course of acute and chronic infectious diseases. The investigation of their global distribution, pronounced genetic and antigenic diversity as well as the molecular mechanisms allowing long-term persistence in hostile and unusual microbial habitats, is a challenge for scientists of many different disciplines world-wide. With a focus on the molecular microbiology aspects, this review summarizes recent trends in Helicobacter and Campylobacter research by highlighting selected presentations at the 11th CHRO conference. The topics include the discovery of new virulence factors, functional analysis of protein secretion systems, host signalling pathways, adaptation to stress conditions, global gene regulation, and genetic variability.

To determine the role of enteric pathogens in acute childhood diarrhoea in Hong Kong, 388 children with diarrhoea and 306 children of similar age without diarrhoea were evaluated in a hospital-based study during a one-year period from August 1994 to July 1995. Of the diarrhoeal cases, 55% were under 1 year and 95% were below 5 years of age. On admission, 22% had some dehydration but none was severely dehydrated. All children were well nourished. Oyer 60% of children with diarrhoea had one or more pathogens in their stool. Rotavirus was the most commonly isolated pathogen (34.6%), followed by Salmonella (23.3%), Campylobacter (4.7%) and Shigella (2.1%). Rotavirus was not assessed in the controls and was detected mainly during the winter months December to February. Bacterial pathogens were identified more commonly in diarrhoea patients (30%) than in controls (5.6%) (P < 0.001). Despite rapid recent socioeconomic development in Hong Kong, non-typhoidal Salmonella diarrhoea remains a significant local problem in infants under 1 year. Further detailed assessment of the transmission and prevention of this infection is required.

Examination of strains of Campylobacter jejuni, Campylobacter coli, and Campylobacter fetus by electron microscopy revealed that they produced peritrichous pilus-like appendages when the bacteria were grown in the presence of bile salts. Various bile-salt supplements were used and it was found that deoxycholate and chenodeoxycholic acid caused a significant enhancement of pilus production and resulted in a highly aggregative phenotype. Morphologically, the pili were between 4 and 7 nm in width and were greater than 1 micron in length. A gene, termed pspA, which encodes a predicted protein resembling protease IV of Escherichia coli, was identified in C. jejuni strain 81-176. A site-specific insertional mutation within this gene resulted in the loss of pilus synthesis as determined by electron microscopy. Insertions upstream and downstream of the gene had no effect on pilus production. The non-piliated mutant of strain 81-176 showed no reduction in adherence to or invasion of INT 407 cells in vitro. However, this mutant, while still possessing the ability to colonize ferrets, caused significantly reduced disease symptoms in this animal model.

Two children with protracted gastrointestinal symptoms were found to be chronically excreting enteropathogenic bacteria in their faeces. Withdrawal of cows' milk protein from their diets resulted in clinical recovery and stool cultures became negative, suggesting that allergy to cows' milk may have contributed to their bacterial carrier state.

The incidence of 'thermophilic' campylobacters in foods and environmental samples has been studied over a two-year period. Of 781 environmental samples, 529 (67%) were found to contain campylobacters, and campylobacters were isolated from 835 (39%) of 2116 food samples. Sewage was almost always contaminated with campylobacters (96.6% of samples) and of the food samples both poultry (55.5%) and offal (47.0%) were commonly contaminated. Determination of the heat-stable serotypes of all strains isolated from these sources and of 921 strains isolated from human faeces showed that there was a wide distribution of serotypes in most types of sample. Serotype Pen 2 was the commonest type found in human faeces (18.9%) and it was also commonest in offal (21.3%), beef (40.0%), sewage (17.7%) and was the third commonest type in poultry. A comparison of culture media and conditions for optimal production of both cytotoxic and cytotonic enterotoxins showed that Brucella Broth incubated under microaerobic conditions for 24 h at 42 degrees C was suitable for both toxins. Detection of cytotoxic activity was most sensitive using HeLa cells. The sensitivities of two ELISA systems and a Chinese Hamster Ovary tissue culture assay for detection of cytotonic enterotoxin were comparable. Not all strains isolated from cases of enteritis in human beings produced toxin; 23.1% produced cytotonic enterotoxin and 17.5% produced cytotoxin. There was no correlation between serotype and toxin production. The wide distribution of campylobacters, indistinguishable from those isolated from cases of enteritis in human beings, leads us to conclude that simplistic statements suggesting that one particular type of food is primarily responsible for cases of human disease should not be made.