Clinical pathology of foodborne diseases: notes on the patient with foodborne gastrointestinal illness

Prevalence and pattern of bacteria and intestinal parasites among food handlers in the Federal Capital Territory of Nigeria

BACKGROUND

In developing countries, biological contaminants largely bacteria and other parasites constitute the major causes of food-borne diseases often transmitted through food, water, nails, and fingers contaminated with faeces. Accordingly, food-handlers with poor personal hygiene could be potential sources of infections by these micro-organisms.

OBJECTIVE

This study was aimed at determining the prevalence and pattern of bacteria and intestinal parasites among food handlers in the Federal Capital Territory.

MATERIALS AND METHODS

The study was a descriptive one in which a multistage sampling technique was employed to select 168 food handlers of various types. Subjects' stool, urine, and fingernail analyses were carried out and the result scientifically scrutinized.

RESULTS

FINGERNAIL BACTERIA ISOLATES INCLUDE: E. Coli (1.8%), coagulase-negative staphylococcus (17.9%), Staphylococcus aureus(7.1%), Klebsiella species (2.4%), Serratia species (1.2%), Citrobacter species (1.2%), and Enterococcus species (1.8%). The subjects' stool samples tested positive: For A. lumbricoides (14.9%), T. trichuria (1.8%), S. starcolaris (3.0%), E. histolytica (10.7%), G. lambilia (1.8%), S. mansoni (1.2%), and Taenia species (4.8%). Furthermore, 42.3% and 15.5% of the stool specimen tested positive for Salmonella and Shigella species, respectively.

CONCLUSION

Food establishments should screen and treat staff with active illness, and regularly train them on good personal and workplace hygiene practices.

Electrochemical immunosensor for multiplexed detection of food-borne pathogens using nanocrystal bioconjugates and MWCNT screen-printed electrode

Bacterial food poisoning is an ever-present threat that can be prevented with proper care and handling of food products. A disposable electrochemical immunosensor for the simultaneous measurements of common food pathogenic bacteria namely Escherichia coli O157:H7 (E. coli), campylobacter and salmonella were developed. The immunosensor was fabricated by immobilizing the mixture of anti-E. coli, anti-campylobacter and anti-salmonella antibodies with a ratio of 1:1:1 on the surface of the multiwall carbon nanotube-polyallylamine modified screen printed electrode (MWCNT-PAH/SPE). Bacteria suspension became attached to the immobilized antibodies when the immunosensor was incubated in liquid samples. The sandwich immunoassay was performed with three antibodies conjugated with specific nanocrystal (α-E. coli-CdS, α-campylobacter-PbS and α-salmonella-CuS) which has releasable metal ions for electrochemical measurements. The square wave anodic stripping voltammetry (SWASV) was employed to measure released metal ions from bound antibody nanocrystal conjugates. The calibration curves for three selected bacteria were found in the range of 1×10(3)-5×10(5) cells mL(-1) with the limit of detection (LOD) 400 cells mL(-1) for salmonella, 400 cells mL(-1) for campylobacter and 800 cells mL(-1) for E. coli. The precision and sensitivity of this method show the feasibility of multiplexed determination of bacteria in milk samples.

Analyses of livestock production, waste storage, and pathogen levels and prevalences in farm manures

Survey results describing the levels and prevalences of zoonotic agents in 1,549 livestock waste samples were analyzed for significance with livestock husbandry and farm waste management practices. Statistical analyses of survey data showed that livestock groups containing calves of <3 months of age, piglets, or lambs had higher prevalences and levels of Campylobacter spp. and Escherichia coli O157 in their wastes. Younger calves that were still receiving milk, however, had significantly lower levels and prevalence of E. coli O157. Furthermore, when wastes contained any form of bedding, they had lowered prevalences and levels of both pathogenic Listeria spp. and Campylobacter spp. Livestock wastes generated by stock consuming a diet composed principally of grass were less likely to harbor E. coli O157 or Salmonella spp. Stocking density did not appear to influence either the levels or prevalences of bacterial pathogens. Significant seasonal differences in prevalences were detected in cattle wastes; Listeria spp. were more likely to be isolated in March to June, and E. coli O157 was more likely to be found in May and June. Factors such as livestock diet and age also had significant influence on the levels and prevalences of some zoonotic agents in livestock wastes. A number of the correlations identified could be used as the basis of a best-practice disposal document for farmers, thereby lowering the microbiological risks associated with applying manures of contaminated livestock to land.

Levels of zoonotic agents in British livestock manures

AIMS

To determine the prevalence and levels of zoonotic agents in livestock wastes.

METHODS AND RESULTS

A proportionally weighted survey was undertaken and livestock waste samples analysed quantitatively for Escherichia coli O157, pathogenic Listeria, Salmonella, Campylobacter, Giardia and Cryptosporidium. A significant proportion of wastes contained at least one zoonotic agent. Relationships were found between dry matter content and the presence and levels of some zoonotic agents.

CONCLUSIONS

British livestock wastes contain measurable levels of the zoonotic agents that cause most cases of gastroenteritis in the UK.

SIGNIFICANCE AND IMPACT OF THE STUDY

Animal wastes are disposed of by spreading to agricultural land used for the production of crops and livestock grazing. As British wastes are contaminated with significant levels of zoonotic agents, the practice may represent a way for pathogens to travel further up the food chain.

Antimicrobial drug delivery in food animals and microbial food safety concerns: an overview of in vitro and in vivo factors potentially affecting the animal gut microflora

This review provides an overview of considerations particular to the delivery of antimicrobial agents to food animals. Antimicrobial drugs are used in food animals for a variety of purposes. These drugs may have therapeutic effects against disease agents, or may cause changes in the structure and/or function of systems within the target animal. Routes of administration, quantity, duration, and potency of an antimicrobial drug are all important factors affecting their action(s) and success. Not only might targeted pathogens be affected, but also bacteria residing in (or on) the treated food animals, especially in the intestines (gastrointestinal tract microflora). Resistance to antimicrobial agents can occur through a number of mechanisms. The extent to which resistance develops is greatly affected by the amount of drug [or its metabolite(s)] a bacterium is exposed to, the duration of exposure, and the interaction between an individual antimicrobial agent and a particular bacterium. The impact of antimicrobial agents on the emergence of resistance in vitro and in vivo may not readily correlate.

From farm to table to brain: foodborne pathogen infection and the potential role of the neuro-immune-endocrine system in neurotoxic sequelae

The American diet is among the safest in the world; however, diseases transmitted by foodborne pathogens (FBPs) still pose a public health hazard. FBPs are the second most frequent cause of all infectious illnesses in the United States. Numerous anecdotal and clinical reports have demonstrated that central nervous system inflammation, infection, and adverse neurological effects occur as complications of foodborne gastroenteritis. Only a few well-controlled clinical or experimental studies, however, have investigated the neuropathogenesis. The full nature and extent of neurological involvement in foodborne illness is therefore unclear. To our knowledge, this review and commentary is the first effort to comprehensively discuss the issue of FBP induced neurotoxicity. We suggest that much of this information supports the role of a theoretical model, the neuro-immune-endocrine system, in organizing and helping to explain the complex pathogenesis of FBP neurotoxicity.