Source-separated blackwater from low-flush toilets contains plant-available nutrients and can be used as a fertilizer. The aim of the study was to evaluate the impact on pathogen inactivation when treating blackwater with urea and/or lime. Blackwater was spiked with Salmonella typhimurium, Escherichia coli O157, Enterococcus faecalis, and Ascaris suum eggs, and treated with urea and/or lime in concentrations up to 0.1% w/w. The bottles were kept in a storage facility (manure slurry tank) for 102 days while monitoring the pathogen concentrations. The treatment time needed to meet the requirement for Salmonella and E. coli reduction could be reduced at least six-fold. The enterococci were more persistent, and only the highest treatment doses had a significantly higher inactivation than the controls. The Ascaris egg viability was only reduced by around 50%, so higher urea/lime doses and/or longer treatment times are required to fulfill the treatment requirements of 3 log10 reductions of parasite eggs.
Certain pheno- and genotype properties of S. typhimurium and some other representatives of Enterobacteriaceae resistant to antimicrobial drugs were studied. The strains were isolated from children with salmonellosis within 4 months when an infection hospital was subjected to microbiological observation. It was shown that by their antibiotic resistance, phagovars and molecular weights of the plasmid DNas, the strains S. typhimurium were similar to those isolated during hospital infections. The conjugative plasmids responsible for antibiotic resistance in some strains did not differ in their molecular weights and antibiotic resistance markers. The strains S. typhimurium similar in their pheno- and genotype properties were isolated only from 2 patients which allowed one to consider it possible that the patients were infected by the strains of common genesis. Analysis of nonpathogenic representatives of Enterobacteriaceae isolated from the patients along with the S. typhimurium strains confirmed the fact that the patients were infected with the same pathogenic strain.
In February 1976 an outbreak of gastroenteritis occurred among 819 aircraft passengers to and from Gran Canaria. 360 of them had gastroenteritis and 88 were hospitalized. Fecal specimens were collected from 710 of the passengers and 344 of them were positive for Salmonella typhimurium phage type 15. Food served on the flight was the source of infection. The repeated incidences of this kind support the necessity of laying down rules and recommendations for the control of air catering services.
BACKGROUND: Food-borne salmonella infections have become a major problem in industrialized countries. The strain of Salmonella enterica serotype typhimurium known as definitive phage type 104 (DT104) is usually resistant to five drugs: ampicillin, chloramphenicol, streptomycin, sulfonamides, and tetracycline. An increasing proportion of DT104 isolates also have reduced susceptibility to fluoroquinolones. METHODS: The Danish salmonella surveillance program determines the phage types of all typhimurium strains from the food chain, and in the case of suspected outbreaks, five-drug-resistant strains are characterized by molecular methods. All patients infected with five-drug-resistant typhimurium are interviewed to obtain clinical and epidemiologic data. In 1998, an outbreak of salmonella occurred, in which the strain of typhimurium DT104 was new to Denmark. We investigated this outbreak and report here our findings. RESULTS: Until 1997, DT104 infections made up less than 1 percent of all human salmonella infections. The strain isolated from patients in the first community outbreak of DT104 in Denmark, in 1998 was resistant to nalidixic acid and had reduced susceptibility to fluoroquinolones. The outbreak included 25 culture-confirmed cases. Eleven patients were hospitalized, and two died. The molecular epidemiology and data from patients indicated that the primary source was a Danish swine herd. Furthermore, the investigation suggested reduced clinical effectiveness of treatment with fluoroquinolones. CONCLUSIONS: Our investigation of an outbreak of DT104 documented the spread of quinolone-resistant bacteria from food animals to humans; this spread was associated with infections that were difficult to treat. Because of the increase in quinolone resistance in salmonella, the use of fluoroquinolones in food animals should be restricted.
Comment In: N Engl J Med. 2000 Mar 2;342(9):66110702060
In November-December 2008, Norway and Denmark independently identified outbreaks of Salmonella Typhimurium infections characterised in the multiple-locus variable number of tandem repeats analysis (MLVA) by a distinct profile. Outbreak investigations were initiated independently in the two countries. In Denmark, a total of 37 cases were identified, and multiple findings of the outbreak strain in pork and pigs within the same supply chain led to the identification of pork in various forms as the source. In Norway, ten cases were identified, and the outbreak investigation quickly indicated meat bought in Sweden as the probable source and the Swedish authorities were alerted. Investigations in Sweden identified four human cases and two isolates from minced meat with the distinct profile. Subsequent trace-back of the meat showed that it most likely originated from Denmark. Through international alert from Norway on 19 December, it became clear that the Danish and Norwegian outbreak strains were identical and, later on, that the source of the outbreaks in all three countries could be traced back to Danish pork. MLVA was instrumental in linking the outbreaks in the different countries and tracing the source. This outbreak illustrates that good international communication channels, early alerting mechanisms, inter-sectoral collaboration between public health and food safety authorities and harmonised molecular typing tools are important for effective identification and management of cross-border outbreaks. Differences in legal requirements for food safety in neighbouring countries may be a challenge in terms of communication with consumers in areas where cross-border shopping is common.
An outbreak of Salmonella typhimurium infection, affecting 170 people in Funen, Denmark, was detected in late summer 1996. To detect risk factors for S. typhimurium infection and test the hypothesis that pork originating from a local slaughterhouse was the source, a matched case-control study of 47 cases and 89 controls was conducted. No single food item could be associated with S. typhimurium infection. However, of 29 cases, 24 (83%) had consumed pork which could be traced to the slaughterhouse. In comparison, 25 (46%) of 54 controls had consumed pork of the same origin (odds ratio: 6.7; 95% confidence interval: 1.8-23.5; p = 0.003). The results showed that consumption of pork from the concerned slaughterhouse was strongly associated with S. typhimurium infection.
Between April and June 2010, a small national outbreak of Salmonella Typhimurium with a particular multilocus variable-number tandem repeat analysis (MLVA) type was identified in Denmark through laboratory-based surveillance. The outbreak involved twenty cases, primarily living within the greater Copenhagen area. Half of the cases were children aged ten years or younger and 12 were male; three cases were hospitalised.A matched case-control study showed a strong link between illness and eating a particular salami product containing pork and venison, matched odds ratio(mOR):150, confidence interval (CI): 19?1,600. The salami had been produced in Germany. Microbiological confirmation in food samples was sought but not obtained. Danish consumers were notified that they should return or dispose of any packages from the suspected salami batch. Because the salami product had potentially been sold in other European countries, the European Centre for Disease Prevention and Control urgent enquiry and Rapid Alert System for Food and Feed systems were used to highlight the possibility of outbreaks in these countries. Case-control studies area strong tool in some outbreak investigations and evidence from such studies may give sufficient information to recall a food product.