Stable Concentrated Emulsions of the 1-Monoglyceride of Capric Acid (Monocaprin) with Microbicidal Activities against the Food-Borne Bacteria Campylobacter jejuni, Salmonella spp., and Escherichia coli

Of 11 fatty acids and monoglycerides tested against Campylobacter jejuni, the 1-monoglyceride of capric acid (monocaprin) was the most active in killing the bacterium. Various monocaprin-in-water emulsions were prepared which were stable after storage at room temperature for many months and which retained their microbicidal activity. A procedure was developed to manufacture up to 500 ml of 200 mM preconcentrated emulsions of monocaprin in tap water. The concentrates were clear and remained stable for at least 12 months. They were active against C. jejuni upon 160- to 200-fold dilution in tap water and caused a >6- to 7-log₁₀ reduction in viable bacterial count in 1 min at room temperature. The addition of 0.8% Tween 40 to the concentrates as an emulsifying agent did not change the microbicidal activity. Emulsions of monocaprin killed a variety of Campylobacter isolates from humans and poultry and also killed strains of Campylobacter coli and Campylobacter lari, indicating a broad anticampylobacter activity. Emulsions of 1.25 mM monocaprin in citrate-lactate buffer at pH 4 to 5 caused a >6- to 7-log₁₀ reduction in viable bacterial counts of Salmonella spp. and Escherichia coli in 10 min. C. jejuni was also more susceptible to monocaprin emulsions at low pH. The addition of 5 and 10 mM monocaprin emulsions to Campylobacter-spiked chicken feed significantly reduced the bacterial contamination. These results are discussed in view of the possible utilization of monocaprin emulsions in controlling the spread of food-borne bacteria from poultry to humans.     

Transfer of Campylobacter jejuni from raw to cooked chicken via wood and plastic cutting boards

Aims: We quantified Campylobacter jejuni transferred from naturally contaminated raw chicken fillets and skins to similar cooked chicken parts via standard rubberwood (RW) and polyethylene cutting boards (PE). Methods and Results: RW and PE cutting boards (2·5 × 2·5 cm²) were constructed. RW surfaces were smooth and even, whereas PE was uneven. Scoring with scalpel blades produced crevices on RW and flaked patches on the PE boards. Raw chicken breast fillets or skin pieces (10 g) naturally contaminated with Camp. jejuni were used to contaminate the cutting boards (6·25 cm²). These were then briefly covered with pieces of cooked chicken. Campylobacter jejuni on raw chicken, the boards, and cooked chicken pieces were counted using a combined most‐probable‐number (MPN)‐PCR method. The type of cutting board (RW, PE; unscored and scored) and temperature of cooked chicken fillets and skins were examined. Unscored PE and RW boards were not significantly different in regards to the mean transfer of Camp. jejuni from raw samples to the boards. The mean transfer of Camp. jejuni from scored RW was significantly higher than from scored PE. When the chicken fillets were held at room temperature, the mean transfer of Camp. jejuni from scored RW and PE was found to be 44·9 and 40·3%, respectively. Conclusions: RW and PE cutting boards are potential vehicles for Camp. jejuni to contaminate cooked chicken. Although cooked chicken maintained at high temperatures reduced cross‐contamination via contaminated boards, a risk was still present. Significance and Impact of the Study: Contamination of cooked chicken by Camp. jejuni from raw chicken via a cutting board is influenced by features of the board (material, changes caused by scoring) and chicken (types of chicken parts and temperature of the cooked chicken).     

Quantification of Campylobacter Species Cross-Contamination during Handling of Contaminated Fresh Chicken Parts in Kitchens

Numerous outbreak investigations and case-control studies for campylobacteriosis have provided evidence that handling Campylobacter-contaminated chicken products is a risk factor for infection and illness. There is currently extremely limited quantitative data on the levels of Campylobacter cross-contamination in the kitchen, hindering risk assessments for the pathogen commodity combination of Campylobacter and chicken meat. An exposure assessment needs to quantify the transfer of the bacteria from chicken to hands and the kitchen environment and from there onto ready-to-eat foods. We simulated some typical situations in kitchens and quantified the Campylobacter transfer from naturally contaminated chicken parts most commonly used in Germany. One scenario simulated the seasoning of five chicken legs and the reuse of the same plate for cooked meat. In another, five chicken breast filets were cut into small slices on a wooden board where, without intermediate cleaning, a cucumber was sliced. We also investigated the transfer of the pathogen from chicken via hands to a bread roll. The numbers of Campylobacter present on the surfaces of the chicken parts, hands, utensils, and ready-to-eat foods were detected by using Preston enrichment and colony counting after surface plating on Karmali agar. The mean transfer rates from legs and filets to hands were 2.9 and 3.8%. The transfer from legs to the plate (0.3%) was significantly smaller (P < 0.01) than the percentage transferred from filets to the cutting board and knife (1.1%). Average transfer rates from hands or kitchen utensils to ready-to-eat foods ranged from 2.9 to 27.5%.     

Stable concentrated emulsions of the 1-monoglyceride of capric acid (monocaprin) with microbicidal activities against the food-borne bacteria Campylobacter jejuni, Salmonella spp., and Escherichia coli

Of 11 fatty acids and monoglycerides tested against Campylobacter jejuni, the 1-monoglyceride of capric acid (monocaprin) was the most active in killing the bacterium. Various monocaprin-in-water emulsions were prepared which were stable after storage at room temperature for many months and which retained their microbicidal activity. A procedure was developed to manufacture up to 500 ml of 200 mM preconcentrated emulsions of monocaprin in tap water. The concentrates were clear and remained stable for at least 12 months. They were active against C. jejuni upon 160- to 200-fold dilution in tap water and caused a >6- to 7-log(10) reduction in viable bacterial count in 1 min at room temperature. The addition of 0.8% Tween 40 to the concentrates as an emulsifying agent did not change the microbicidal activity. Emulsions of monocaprin killed a variety of Campylobacter isolates from humans and poultry and also killed strains of Campylobacter coli and Campylobacter lari, indicating a broad anticampylobacter activity. Emulsions of 1.25 mM monocaprin in citrate-lactate buffer at pH 4 to 5 caused a >6- to 7-log(10) reduction in viable bacterial counts of Salmonella spp. and Escherichia coli in 10 min. C. jejuni was also more susceptible to monocaprin emulsions at low pH. The addition of 5 and 10 mM monocaprin emulsions to Campylobacter-spiked chicken feed significantly reduced the bacterial contamination. These results are discussed in view of the possible utilization of monocaprin emulsions in controlling the spread of food-borne bacteria from poultry to humans.     

A survey of enteric bacteria and protozoans in fresh bovine faeces on New Zealand dairy farms

Aims: To determine the counts and/or prevalence in fresh bovine faeces of Escherichia coli, enterococci, Campylobacter, Salmonella, shiga toxin‐producing E. coli (STEC), Giardia and Cryptosporidium, as inputs to numerical models designed to estimate microbial loadings on pasture grazed by cattle in New Zealand. Methods and Results: In each season over one year, samples of freshly deposited bovine faeces were collected from four New Zealand dairy farms (n = 155), and enumerated for E. coli, enterococci, Campylobacter, Giardia and Cryptosporidium. They were also tested for the presence of Salmonella and STEC. The overall median bacterial counts (g^?1 wet weight) were E. coli– 5·9 × 10⁶; enterococci – 1·3 × 10⁴; Campylobacter– 3·9 × 10⁵. All counts were highly variable within and between samplings, and few seasonal or regional patterns emerged. However, mean Campylobacter counts were consistently higher in spring. No Salmonella spp. was detected, and only two samples were positive for STEC. Cryptosporidium and Giardia were isolated from 5·2% and 4·5% of the samples, respectively, yielding low numbers of (oo)cysts (1–25 g^?1 and 1–17 g^?1, respectively). Conclusions: Fresh bovine faeces are a significant source of E. coli, enterococci and Campylobacter on New Zealand pastures, although numbers are likely to vary markedly between faecal samples. Significance and Impact of the Study: The study provides the first significant set of indicator and pathogen counts for one of the largest sources of faecal contamination of natural waters in New Zealand, and will be used to model these inputs.     

Multi‐locus sequence types of Campylobacter carried by flies and slugs acquired from local ruminant faeces

Aims: To assess whether flies and slugs acquire strains of Campylobacter jejuni and Campylobacter coli present in local ruminant faeces. Methods and Results: Campylobacter was cultured from flies, slugs and ruminant faeces that were collected from a single farm in Scotland over a 19‐week period. The isolates were typed using multi‐locus sequence typing (MLST) and compared with isolates from cattle and sheep faeces. Campylobacter jejuni and Camp. coli were isolated from 5·8% (n = 155, average of 75 flies per pool) and 13·3% (n = 15, average of 8·5 slugs per pool) of pooled fly and slug samples, respectively. The most common sequence type (ST) in flies was Camp. coli ST‐962 (approx. 40%) regardless of the prevalence in local cattle (2·3%) or sheep (25·0%) faeces. Two positive slug pools generated the same ST that has not been reported elsewhere. Conclusions: Despite their low carriage rate, flies are able to acquire Campylobacter STs that are locally present, although the subset carried may be biased when compared to local source. Slugs were shown to carry a previously unreported Campylobacter ST. Significance and Impact of the Study: This study has demonstrated that flies carry viable Campylobacter and may contribute to the transfer of STs within and between groups of animals on farms. Further, they may therefore present a risk to human health via their contact with ready‐to‐eat foods or surfaces.     

Campylobacter genotypes from poultry transportation crates indicate a source of contamination and transmission

Aims: Crates used to transport live poultry can be contaminated with Campylobacter, despite periodic sanitization, and are potential vectors for transmission between flocks. We investigated the microbial contamination of standard and silver ion containing crates in normal use and the genetic structure of associated Campylobacter populations. Methods and Results: Bacteria from crates were enumerated by appropriate culture techniques, and multilocus sequence typing (MLST) was used to determine the genetic structure of Campylobacters isolated from standard and silver ion containing crates. Compared to standard crates, counts of bacteria, including Campylobacter, were consistently lower on silver ion containing crates throughout the decontamination process. In total, 16 different sequence types were identified from 89 Campylobacter jejuni isolates from crates. These were attributed to putative source population (chicken, cattle, sheep, the environment, wild bird) using the population genetic model, structure . Most (89%) were attributed to chicken, with 22% attribution to live chicken and 78% to retail poultry meat. MLST revealed a progressive shift in allele frequencies through the crate decontamination process. Campylobacter on crates survived for at least 3 h after sanitization, a period of time equivalent to the journey from the processing plant to the majority of farms in the catchment, showing the potential for involvement of crates in transmission. Conclusions: Inclusion of a silver ion biocide in poultry transportation crates to levels demonstrating acceptable antibacterial activity in vitro reduces the level of bacterial contamination during normal crate use compared to standard crates. Molecular analysis of Campylobacter isolates indicated a change in genetic structure of the population with respect to the poultry‐processing plant sanitization practice. Significance and Impact of the Study: The application of a sustainable antimicrobial to components of poultry processing may contribute to reducing the levels of Campylobacter circulating in poultry.     

Disinfection of Bacillus subtilis spore-contaminated surface materials with a sodium hypochlorite and a hydrogen peroxide-based sanitizer

Aims: To evaluate a sodium hypochlorite and hydrogen peroxide solution (Ox‐B7) as a potential decontaminant of Bacillus subtilis spore‐contaminated surface materials (porous and nonporous). Methods and Results: Test materials were contaminated with B. subtilis spores to a final concentration in the range of 5·7–6·6 log CFU cm^?2. Ox‐B7 reduced spore counts by 99·999% (5 log) for both porous and nonporous surfaces within a 5‐min contact. Treatment with equivalent concentrations of only sodium hypochlorite reduced spore counts by 99% (2 log) on porous materials and by 99·99% (4 log) on nonporous materials. Hydrogen peroxide treatments reduced spores by less than 90% (<1 log) on both porous and nonporous materials when compared with untreated samples. Conclusions: A combination of sodium hypochlorite and hydrogen peroxide (Ox‐B7) effectively killed B. subtilis spores on both porous and nonporous surface materials. Significance and Impact of the Study: The combination of sodium hypochlorite and hydrogen peroxide can be used as an alternative disinfectant of spore‐contaminated surface materials, as it is more effective than when hydrogen peroxide or sodium hypochlorite are used separately.     

A survey of fluoroquinolone resistance in Escherichia coli and thermophilic Campylobacter spp. on poultry and pig farms in Great Britain

Aims: To estimate the proportions of farms on which broilers, turkeys and pigs were shedding fluoroquinolone (FQ)-resistant Escherichia coli or Campylobacter spp. near to slaughter. Methods and Results: Freshly voided faeces were collected on 89 poultry and 108 pig farms and cultured with media containing 1·0 mg l⁻¹ ciprofloxacin. Studies demonstrated the specificity of this sensitive method, and both poultry and pig sampling yielded FQ-resistant E. coli on 60% of farms. FQ-resistant Campylobacter spp. were found on around 22% of poultry and 75% of pig farms. The majority of resistant isolates of Campylobacter (89%) and E. coli (96%) tested had minimum inhibitory concentrations for ciprofloxacin of ≥8 mg l⁻¹. The proportion of resistant E. coli and Campylobacter organisms within samples varied widely. Conclusions: FQ resistance is commonly present among two enteric bacterial genera prevalent on pig and poultry farms, although the low proportion of resistant organisms in many cases requires a sensitive detection technique. Significance and Impact of the Study: FQ-resistant bacteria with zoonotic potential appear to be present on a high proportion of UK pig and poultry farms. The risk this poses to consumers relative to other causes of FQ-resistant human infections remains to be clarified.     

Occurrence of thermotolerant Campylobacter species in surface waters of a Mediterranean area and in its prevailing pollution sources

Aims: To determine the prevalence of Campylobacter in surface waters of a highly populated Mediterranean area. Methods and Results: Surface water and wastewater samples were collected from an area in the north‐east of Spain during a 2‐year study. All the samples were analysed using the MPN method and Multiplex PCR to quantify and identify Campylobacter. It was detected in 82% of the samples from the Llobregat River with a mean of 1·3 MPN 100 ml^?1. The lowest counts were obtained in summer. Campylobacter coli was the predominant species in this river. The bacteria were isolated from marsh water but not from seawater samples. The highest counts of campylobacters were found in poultry wastewater where Camp. jejuni was the predominant species, as in urban sewage. In pig slurry, Camp. coli was the only species detected. Conclusions: Campylobacter jejuni and Camp. coli are present and widely distributed in the surface water of the studied area. The two species co‐exist, with Camp. coli being predominant. In river water, campylobacter counts presented a seasonal distribution. No relationship with faecal indicators was found. Significance and Impact of the Study: This study provides the first data on the occurrence and concentrations of thermotolerant campylobacter species in surface water in a Mediterranean area.     

Effect of copper hydroxide sprays for citrus canker control on wild-type Escherichia coli

Aims: To show that application of copper hydroxide citrus sprays mixed with field source water (possibly contaminated) will not support Escherichia coli on plant surfaces. Environmental stresses of transient phyllosphere bacteria and presence of copper will eradicate these bacteria before harvest. Methods and Results: Studies were performed in vitro with bacteria grown in broth and then subjected to field spray copper hydroxide concentrations in the broth and on citrus leaves. Escherichia coli exposed to copper hydroxide in vitro were eradicated from the broth within 6–8 h depending on the broth pH. Even with near neutral pH (7·2), cells began to die immediately after exposure to copper. No E. coli survived on leaf surfaces sprayed with copper. Conclusions: Copper field sprays mixed with water that may contain E. coli can help eliminate E. coli from plant surfaces. Significance and Impact of the Study: HACCP mandates are becoming more restrictive because of the increased illness resulting from food pathogens on fresh produce. Use of potable water in fields, a proposed mandate, is not feasible for large grove owners. These data show that copper sprays aimed at reducing citrus canker also affect E. coli and may help to ease water quality mandates.     

The effects of dietary additives on faecal levels of Lactobacillus spp., coliforms,and Escherichia coli,and faecal prevalence of Salmonella spp. and Campylobacter spp. in US production nursery swine1

Aims: In the United States, carbadox and copper sulfate are growth promoters commonly used in combination in nursery swine diets. Our aim was to determine how selected dietary additives affect selected bacterial populations and pathogens in nursery swine, and compare to larch extract, which contains potential antibacterial activities. Methods and Results: Piglets were weaned and sorted into one of the four treatments: (i) basal diet without antimicrobials; (ii) basal diet with carbadox + copper sulfate; (iii) basal diet + 1000 ppm larch extract; or (iv) basal diet + 2000 ppm larch extract. Diets were fed for a 4‐week period after weaning. In both trials, the carbadox + copper sulfate group consumed more feed over the 4‐week period relative to the other three diet groups (P < 0·05), but did not gain significantly more weight. Faecal shedding of Salmonella spp. was not affected by dietary supplement in either trial, but faecal shedding of Campylobacter spp. was the lowest for the carbadox + copper sulfate diet. In faecal samples collected at the end of each trial, Lactobacillus spp. cell counts for the basal and larch extract diets were nearly 1·0 log₁₀ g^?1 faeces greater (P < 0·05) than the carbadox + copper sulfate group, whereas the coliforms and Escherichia coli were nearly 1·0 log₁₀ g^?1 faeces lower (P < 0·05). Conclusions: Compared to basal fed animals, supplementation with carbadox + copper sulfate significantly altered faecal E. coli, coliform bacteria and Lactobacillus spp. Larch extract has no benefit up to 0·2% of diet in regard to pathogen shedding, whereas carbadox + copper sulfate decreased faecal shedding of Campylobacter spp. Significance and Impact of the Study: Current swine management practices in the United States may be beneficial to managing Campylobacter spp. shedding in nursery swine, but also result in significant changes in the resident gastrointestinal microflora.     

Cross-contamination in the kitchen: estimation of transfer rates for cutting boards, hands and knives

Aims: To quantify cross-contamination in the home from chicken to ready-to-eat salad. Methods and Results: Based on laboratory scenarios performed by de Jong et al. (2008) , transfer rates were estimated for Campylobacter jejuni and Lactobacillus casei as a tracer organism. This study showed that transfer characteristics for both micro-organisms were comparable when washing regimes and transfer via items (cutting board, hands and knives) were compared. Furthermore, the study showed that the use of separate transfer rates for transfer from chicken to items and from items to salad will lead to an overestimation of campylobacteriosis risk. Applying good hygienic practices resulted in final levels of bacteria in the salad below the detection limit. Our study showed that it is important to include these data points in model fitting. Conclusions: Results obtained in observational studies with Lact. casei can be translated to Camp. jejuni using the transfer rates obtained in this study. Cross-contamination by hands, cutting boards and knives was equally important. Significance and Impact of the Study: Cross-contamination should be incorporated in microbiological risk assessments. The present study contributes to this by quantifying transfer of Camp. jejuni and Lact. casei from raw chicken via various contact surfaces into the ready-to-eat product.     

A time series analysis of the relationship of ambient temperature and common bacterial enteric infections in two Canadian provinces

The incidence of enteric infections in the Canadian population varies seasonally, and may be expected to be change in response to global climate changes. To better understand any potential impact of warmer temperature on enteric infections in Canada, we investigated the relationship between ambient temperature and weekly reports of confirmed cases of three pathogens in Canada: Salmonella, pathogenic Escherichia coli and Campylobacter, between 1992 and 2000 in two Canadian provinces. We used generalized linear models (GLMs) and generalized additive models (GAMs) to estimate the effect of seasonal adjustments on the estimated models. We found a strong non-linear association between ambient temperature and the occurrence of all three enteric pathogens in Alberta, Canada, and of Campylobacter in Newfoundland-Labrador. Threshold models were used to quantify the relationship of disease and temperature with thresholds chosen from 0 to −10°C depending on the pathogen modeled. For Alberta, the log relative risk of Salmonella weekly case counts increased by 1.2%, Campylobacter weekly case counts increased by 2.2%, and E. coli weekly case counts increased by 6.0% for every degree increase in weekly mean temperature. For Newfoundland-Labrador the log relative risk increased by 4.5% for Campylobacter for every degree increase in weekly mean temperature.     

Assessment of microbiological quality of food preparation process in some restaurants of Makkah city

Microbiological contamination of food processing surfaces and utensils increases considerably the risk of food-borne illnesses via cross-contamination. Hence, the safety of served meals and beverages can be evaluated through the assessment of the microbiological quality of food contact surfaces in food-serving establishments. This study carried out in Makkah city aimed to assess the microbiological contamination levels on food processing surfaces and utensils in 43 restaurants from the 9 main districts in the city. A total of 294 swab preparations were taken from 16 types of food contact surfaces including cutting boards, food containers, knives, serving dishes and other utensils were examined. Ninety samples (31%) showed more than 10 CFU/cm² which were considered positive for microbiological contamination. Meat chopping devices and cutting boards were found as the most contaminated food contact surfaces (60% and 50%), while washed serving dishes and fridge handles were the least contaminated (21% and 18%). Microorganisms detected in the study were Klebsiella spp. (18.7%), Escherichia coli (17,7%), Staphylococcus aureus (4,4%), Pseudomonas spp. (1.7%), Proteus spp. (0.7%), Bacillus cereus (0.7%), and Candida sp. (0.3%). Klebsiella spp. and E. coli were observed in at least one sample from each of the sixteen different food contact surfaces. The incidence of restaurants with contaminated food contact surfaces was significantly variable among the different districts, with a value as high as 57% in the most affected district and 20% in the less affected. No contamination with Salmonella spp. or Listeria spp. was detected, however, the detection of Bacillus cereus, a toxin-forming microorganism, in two different restaurants underlines the need for continuous microbiological assessment to ensure standard sanitation levels in restaurants and catering establishments of Makkah city.     

Comparison of swabbing and destructive methods for microbiological pig carcass sampling

Aims: To compare the Belgian swabbing sampling method for pig carcasses with the reference destructive method with regard to Escherichia coli and aerobic plate counts, Salmonella and Campylobacter prevalence and their relationship. Methods and Results: Recovery was significantly lower for the swabbing method and corresponded to a recovery of 36% for E. coli counts and 81% for aerobic plate counts in comparison with the destructive method. There was no significant difference between the swabbing and destructive sampling methods for the prevalence of Salmonella or Campylobacter. A higher median for E. coli counts was detected for samples where Salmonella or Campylobacter were detected. The same association was also observed between the median for aerobic plate counts and the presence of Campylobacter. Conclusions: The method of swabbing used, covering 600 cm² on each half‐pig carcass, is efficient for the sampling of pig carcasses in comparison with the reference destructive method. Significance and Impact of the Study: This study describes an efficient method for microbiological pig carcass sampling. The Belgian swabbing method should continue to be used to allow the follow up of bacterial contamination in the Belgian meat production chain.     

A longitudinal study of <Emphasis Type="Italic">Campylobacter</Emphasis> distribution in a turkey production chain

Background  

Campylobacter is the most common cause of bacterial enteritis worldwide. Handling and eating of contaminated poultry meat has considered as one of the risk factors for human campylobacteriosis. Campylobacter contamination can occur at all stages of a poultry production cycle. The objective of this study was to determine the occurrence of Campylobacter during a complete turkey production cycle which lasts for 1,5 years of time. For detection of Campylobacter, a conventional culture method was compared with a PCR method. Campylobacter isolates from different types of samples have been identified to the species level by a multiplex PCR assay.     

Restoring the selectivity of Bolton broth during enrichment for Campylobacter spp. from raw chicken

Aims: When isolating Campylobacter spp. from retail raw chicken using BS EN ISO 10272‐1:2006, contaminants frequently cause overgrowth on mCCDA plates. Therefore, these organisms proliferate in the enrichment medium, Bolton broth, indicating a lack of selectivity in this medium. This study sought to characterize the contaminant flora and to devise a modified Bolton broth to inhibit their growth. Methods and results: Contaminants (n = 30) from separate samples were identified and antibiotic resistances determined. Most (93%) were extended spectrum β‐lactamase (ESBL) producing Escherichia coli, able to hydrolyse the cefoperazone present in Bolton broth and mCCDA. To inhibit these organisms, original formulation Bolton broth was supplemented with potassium clavulanate, at three concentrations, and recoveries of campylobacters from raw chicken were determined. Using standard Bolton broth, only 49% of samples (n = 104) yielded campylobacters, but supplementation with 2 mg l^?1 potassium clavulanate increased this significantly (P < 0·05), with 91% of samples positive. Conclusions: Potassium clavulanate can restore the selectivity of Bolton broth when isolating Campylobacter spp. from raw chicken. Significance and Impact of the Study: Raw chicken is often contaminated with the pathogen Campylobacter, but the ISO methodology for its detection is becoming compromised by the increasing presence of antibiotic‐resistant bacteria. A simple modification ensures effective detection of this pathogen.     

Bacterially contaminated oil mists in engineering works: a possible respiratory hazard

Oil-in-water emulsion cutting fluids are used extensively in the engineering industry and may become contaminated by large numbers of microorganisms from dust, debris, and from the workers' skin. During use, the emulsions are recycled from sumps below the machinery, and may be used for long periods of time before sumps are emptied. Aerosols of these emulsions containing all the components of the oil, including contaminating bacteria, are generated at the moving parts of the machinery. When operating machinery, workers may inhale large numbers of these micro-organisms. Bacteria isolated from the emulsions and from air sampled around machinery were mostly Gram-negative, and were predominantly Pseudomonas species. Inhalation of Gram-negative bacteria may potentially cause respiratory allergy or infection, or may lead to long-term deterioration in lung function in otherwise asymptomatic individuals. Preliminary tests have shown an immunological response, in a worker with work-related respiratory symptoms, to extracts of three Pseudomonas species isolated from emulsion.     

Survey of Campylobacter jejuni in stray cats in southern Italy

Aim: To evaluate the presence of thermotolerant Campylobacter spp. in stray cats in southern Italy. Methods and Results: One hundred and thirteen animals were trapped in two different environments (urban area, harbour area) of the city of Naples. From each cat, rectal swabs were collected. The samples were processed in order to detect thermotolerant Campylobacter spp. by culture methods. The positive samples were then confirmed by multiplex polymerase chain reaction. Campylobacter jejuni was isolated from 19/113 (16·8%) stray cats, whereas Campylobacter coli was not isolated. The cat data (age, environment and sex) were analysed by two statistical analyses using the C. jejuni status (positive/negative) as a dependent variable. As regards statistical regression model results, age and environment were risk factors for C. jejuni positivity. In particular, cats older than 1 year had a significantly higher risk of being positive for C. jejuni than cats aged up to 1 year (OR = 10·440; P = 0·000). Moreover, cats living in the harbour area had a significantly higher risk to be a carrier of C. jejuni than cats living in urban area (OR = 17·911; P = 0·008). Conclusion: The findings of the present survey confirm stray cats as potential carriers of C. jejuni. Significance and Impact of the Study: This is the first study on the prevalence of C. jejuni in stray cats in Europe.