Cross‐contamination during the scalding and plucking of broilers

1. Experiments were carried out in two poultry slaughtering plants to estimate cross‐contamination occurring during the scalding and plucking of broilers.

2. To simulate the external (dust and feather) and internal (intestinal) contamination of broilers the carcasses were artificially contaminated with a strain of Escherichia coli K12.

3. Cross‐contamination occurred at both stages in the processing when the carcasses had been contaminated externally; when the broilers had been contaminated internally slight cross‐contamination occurred only during plucking.

4. Broilers which were contaminated externally before scalding resulted in more numerous carcasses that were contaminated after the whole slaughtering procedure than those contaminated internally.

5. In one processing plant there were fewer contaminated carcasses after cooling than after plucking, while in the other plant no differences were found in the number of positive carcasses after these two stages in processing.     

Removing faecal contamination of broilers by spray‐cleaning during evisceration

1. The faecal contamination of broiler carcasses during evisceration results in an increase in contamination with Enterobacteriaceae, including any salmonellas present.

2. This increase can be prevented completely by spray‐cleaning carcasses during the various stages of evisceration.

3. If the carcasses are cleaned only at the end of the evisceration process, the numbers of Enterobacteriaceae are not reduced to initial levels and Salmonella contamination is less efficiently removed.     

Does blood contamination of urine compromise interpretation of the urine protein to creatinine ratio in dogs?

AIMS: To determine the effect of contamination of urine with 0–5% blood, varying in haematocrit and protein concentrations, on the urine protein to creatinine ratio (UPC) in dogs, and to determine whether the colour of urine can be used to aid interpretation of UPC results.

METHODS: Urine samples were collected by free catch from 18 dogs, all of which had UPC?<0.2. Venous blood samples were also collected from each dog, and the blood from each dog was added to its own urine to produce serial concentrations of 0.125–5% blood. The colour of each urine sample was recorded by two observers scoring them as either yellow, peach, orange, orange/red or red. Protein and creatinine concentrations were determined, and dipstick analysis and sediment examination was carried out on each sample. Based on colour and dipstick analysis, samples were categorised as either having microscopic, macroscopic or gross haematuria. A linear mixed model was used to examine the effect of blood contamination on UPC.

RESULTS: The uncontaminated urine of all 18 dogs had a UPC?<0.2. Adding blood to the urine samples resulted in an increase in UPC at all contamination concentrations compared to the non-contaminated urine (p<0.001). None of the 54 samples with microscopic haematuria had UPC?>0.5. For 108 samples with macroscopic haematuria the UPC was >0.5 in 21 samples (19.4 (95% CI=13.1–27.9)%), and for 54 samples with gross haematuria 39 (72 (CI=59.1–82.4)%) had a UPC?>0.5. No samples had a UPC?>2.0 unless the blood contamination was 5% and only 3/18 (17%) samples at this blood contamination concentration had a UPC?>2.0.

CONCLUSIONS AND CLINICAL RELEVANCE: This study showed that while blood contamination of ≥0.125% does increase the UPC, if the urine remains yellow (microscopic haematuria), then there is negligible chance that a UPC?>0.5 will be solely due to the added blood. In that scenario, attributing the proteinuria present to the haematuria in the sample would be inappropriate. However blood contamination that results in discolouration of the urine sample from yellow (indicating macroscopic or gross haematuria) could increase the UPC above the abnormal range and would need to be considered as a differential for the proteinuria. Thus knowledge of urine colour, even if limited to simple colour scores (yellow, discoloured, red) could be utilised to aid interpretation of the UPC in samples with haematuria.     

Bacterial contamination on eggs during incubation and hatching,and of fluffs of newly‐hatched chicks

1. Average numbers of bacteria on clean and dirty eggs produced from a specified‐pathogen‐free chicken flock were 10^3.0 and 10^4.5, respectively. When the eggs were washed with running tap water at about 40°C, the respective bacterial counts were reduced to 10^2.0 and 10^2.7, the latter difference being not significant.

2. After fumigation with formaldehyde from 40 ml formalin (372 g formaldehyde/1) and 20 g potassium permanganate/m³ for 1 h, no bacteria were recovered from clean eggs by agar plate culture, while a small number of bacteria were detected in three out of five dirty eggs.

3. Average numbers of bacteria detected in clean fumigated eggs were 10^0.8 to 10^1.1 during the first 19 d of incubation and 10^1.2 and 10^1.4 were recovered on days 20 and 21 of incubation, respectively. At the end of hatching, eggs containing dead embryos were highly contaminated with 10^3.8 organisms on average.

4. Fluffs of newly‐hatched chicks scattered inside the hatcher were contaminated with bacteria at 10^4.0 to 10^8.4 organisms/g. Water in the basin placed in the hatcher and floating fluffs in water were highly contaminated with bacteria.     

Will the effectiveness of the immunization of chicks with live Salmonella vaccines be affected by maternal antibodies?

In the progeny of breeder birds which had been vaccinated with live Salmonella Typhimurium and inactivated Salmonella Enteritidis vaccines, the caecal and systemic colonisation by a live Salmonella Enteritidis and a live Salmonella Typhimurium vaccine was studied. The efficacy of the oral immunisation of chicks from vaccinated and non-vaccinated breeders with a live Salmonella Enteritidis vaccine on day 1 of age was studied by an experimental challenge with Salmonella Enteritidis on day 30 of age. Antibody production of isotypes IgG, IgA and IgM was determined in sera and jejunum of the birds. Vaccination of parent birds resulted in an increase of the antibody concentration in sera and jejunum of the chicks. Own antibody production after administration of the live Salmonella vaccine to the day-old chicks was not detected until day 21 of life. Compared to controls, the number of vaccine organisms in the caeca of the progeny of vaccinated breeder birds was reduced by 0.5-1.5 log10 units. The reduction of the Salmonella Enteritidis vaccine was more pronounced than that of the Salmonella Typhimurium vaccine. However, the reduced colonisation by the live Salmonella vaccine strain did not impair the efficacy of the immunisation of the chicks. To ensure efficacy of the active oral immunisation of chicks from vaccinated parent birds with attenuated live Salmonella vaccines also in case where amounts of maternally transferred antibodies are even higher, it should be guaranteed that chicks take in via drinking water the recommended dose of the vaccine strain. In this connection, factors like the low intake of drinking water by very young chicks, the concentration of the vaccine organisms in the water and the survival of the vaccine should also be considered.     

Evaluation of bacterial contamination on surgical drapes following use of the Bair Hugger? forced air warming system

This pilot study determined the rate of bacterial contamination on surgical drapes of small animal patients warmed intra-operatively with the Bair Hugger^® forced air warming system compared to a control method. Surgical drapes of 100 patients undergoing clean surgical procedures were swabbed with aerobic culturettes at the beginning and end of surgery. Samples were cultured on Trypticase soy agar. Contamination of the surgical drapes was identified in 6/98 cases (6.1%). There was no significant difference in the number of contaminated surgical drapes between the Bair Hugger^® and control groups (P = 0.47).     

Salmonella Brandenburg — emergence of a variant strain on a sheep farm in the South Island of New Zealand

AIM: To compare the rectal and I/V administration of tramadol in dogs, to assess both its pharmacokinetic properties and absolute bioavailability.

METHODS: After rectal administration via suppositories and I/V injection of tramadol (4 mg/kg), the concentration of tramadol and its main metabolites, O-desmethyl-tramadol (M1), N-desmethyl-tramadol (M2) and N,O-didesmethyl-tramadol (M5), were determined in plasma, using high-performance liquid chromatography (HPLC). A balanced cross-over study was used, involving six male Beagle dogs.

RESULTS: Plasma concentrations after rectal and I/V administration were fitted on the basis of mono- and bi-compartmental models, respectively. Following rectal administration tramadol was detected from 5 minutes up to 10 hours, in lesser amounts than M5 and M2, while M1 was detected in negligible amounts. Following I/V administration tramadol was detected up to 10 hours, M2 and M5 were detected at similar concentrations, and M1 was present at low concentrations. The area under the curve (AUC) of the three metabolites did not differ significantly after either route of administration of tramadol. The absolute bioavailability of tramadol via rectal administration was 10 (SD 4)%.

CONCLUSIONS: After rectal administration of tramadol suppositories, absorption of the active ingredient was rapid, but its metabolism quickly transformed the parent drug to high levels of M2 and M5.

CLINICAL RELEVANCE: In the dog, rectal pharmaceutical formulation of tramadol would have a different pharmacokinetic behaviour than in humans.     

Bacterial contamination of colostrum fed to newborn calves in Québec dairy herds

A convenience sample of 234 colostral specimens, collected directly from the nursing bottle immediately prior to the first feeding, was studied. Samples originated from 6 farms and were collected over 24 months. Routine bacteriologic techniques were used to quantify the bacterial load of the colostrum, as well as to identify the bacteria. Overall, at least 1 microorganism was cultured from 221 colostral samples (94.4%). By using the upper tolerance level of 100,000 bacteria/mL, 84 samples (35.9%) were considered contaminated. Staphylococcus spp. (57.7%), gram-negative rods (47.9%), coliforms (44.0%), and Streptococcus uberis (20.5%) were among the most frequently isolated bacteria. The relative risk (RR) of contamination with more than 100,000 bacteria/mL was significantly greater in warm months [RR = 2.55, 95% confidence interval (CI): 1.63 to 4.02] than in cool months and in colostrum offered to male calves (RR = 1.55, 95% CI: 1.09 to 2.20). Bacterial load was also associated with the farm of origin (P < 0.0001). When assessing colostrum management, one should consider bacterial contamination. Multiple factors are likely associated with the degree of contamination, and farm-specific factors may be important. Further studies are necessary to evaluate the impact of bacterial contamination of colostrum on neonatal health.     

Differential gene expression of antimicrobial peptides β defensins in the gastrointestinal tract of Salmonella serovar Pullorum infected broiler chickens

Salmonella enterica serovar Pullorum causes substantial mortality in chicks as well as results in persistent infection and vertical transmission in layer birds. An effective innate immune response in the early stages of infection could reduce bacterial colonization and mortality in chicks and persistency of infection in later stages. β Defensins (AvBDs) are now considered as one of the key components of innate immunity in avian species. In the present study, we quantified the mRNA expression levels of AvBDs (1–14) by real-time PCR in the gastrointestinal (GI) tissues (duodenum, jejunum, ileum and caecum) of 3-day-old broiler chicks after 24 h of oral infection with Salmonella Pullorum. Quantitative real-time PCR analysis revealed significant (P < 0.05) upregulation of AvBD3, 4, 5, 6 and 12 and a significant (P < 0.05) down regulation in the expressions of AvBD10, 11, 13 and 14 in one or few GI tissues, while no significant changes were observed for AvBD1, 2, 7, 8 and 9 gene expressions in any of the GI tissues investigated upon infection with S. Pullorum. Most substantial change in gene expression was found for AvBD5, being significantly (P < 0.01) upregulated in most of the GI tissues investigated. The differential expression levels of β defensins shed light on tailored innate immune response induced by S. Pullorum during the early stages of infection in chicks.     

Effects of sexual maturation and Salmonella infection on the expression of avian β-defensin genes in the chicken testis

Rooster infertility is a major concern in the poultry industry and protection of the male reproductive organs from pathogens is an essential aspect of reproductive physiology. During the last years, research on antimicrobial protection has elucidated the critical role of the antimicrobial peptides avian β-defensins (AvBDs) in the innate immunity in chickens. AvBDs have been reported to be expressed in the hen reproductive organs, providing protection against microbial pathogens including Salmonella Enteritidis (SE). However, mechanisms of antimicrobial protection of rooster reproductive organs and especially the testis, mediated by AvBDs are poorly understood. The aim of this study was to investigate the expression of the complete family of the 14 AvBD genes, in the rooster testis in vivo, to determine whether sexual maturation affects their testicular mRNA abundance and to investigate whether SE infection alters their expression. Expression analysis revealed that 9 members of the AvBD family, namely AvBD1, 2, 4, 5, 6, 9, 10, 12 and 14 were expressed in the testis. Quantitative real-time PCR analysis revealed that the mRNA abundance of three AvBDs was up regulated and of three AvBDs was down regulated with respect to sexual maturation. In addition, SE infection resulted in a significant induction of AvBD4, 10, 12 and 14 in the testis of sexually mature roosters. These findings provide strong evidence to suggest that an AvBD-mediated immune response mechanism exists in the rooster testis providing protection against bacterial pathogens including Salmonella species.     

Genetic analysis of multi-drug resistance and the clonal dissemination of β-lactam resistance in Salmonella Infantis isolated from broilers

An epidemiologic study was conducted to investigate the incidence and characterize the antimicrobial resistance determinants, analyzing plasmid profiles, and establishing the genetic relationship among β-lactam-resistant isolates of Salmonella Infantis from broilers in Southern Japan. A total of 120 isolates were recovered from 56 flocks belonging to 44 holdings during 2004–2006. The percentages of resistance were as follows: ampicillin (24%), cephalothin (23%), cefoxitin (0%), ceftazidime (11%), cefotaxime (11%), chloramphenicol (0%), kanamycin (7.5%), ofloxacin (20%), oxytetracycline, streptomycin and sulfamethoxazole (100%) and trimethoprim (75%). The incidence of bla_TEM-encoded β-lactam resistance in 2004–2006 was significantly higher than in 1998–2003 (P < 0.001). BlnI-digested PFGE patterns generated two related clusters implicated in the dissemination of β-lactam resistance. Two types of plasmid profiles were observed and two plasmids of ca. 50 and 180-kb size were carried by β-lactam-resistant isolates. Streptomycin resistance was conferred by aadA1 (n = 116), aadA1-aadA2 (n = 1), and aadA1-strA-strB (n = 3). Resistances to kanamycin, oxytetracycline, sulfamethoxazole and trimethoprim were conferred by aphA1 (n = 9, 100%), tetA (n = 120, 100%) sul1 (n = 120, 100%) and dfrA5 (n = 90, 100%), respectively. Two types of class 1 integrons were detected: 1.0 kb (n = 120) and, 1.0/1.5 kb (n = 3). Integrons of 1.0/1.5 kb were found in isolates with the aadA1-strA-strB gene combination. For the first time, all S. Infantis isolates showed resistance to at least three classes of antimicrobial agents; and the intestinal tract of healthy poultry was a reservoir of the extended-spectrum cephalosporin-resistant isolates of serovar Infantis.     

Use of a marker organism in poultry processing to identify sites of cross‐contamination and evaluate possible control measures

1. Nine different sites at a poultry processing plant were selected in the course of a hazard analysis to investigate the degree of microbial cross‐contamination that could occur during processing and the effectiveness of possible control measures.

2. At each site, carcases, equipment or working surfaces were inoculated with a non‐pathogenic strain of nalidixic acid‐resistant Escherichia coli K12; transmission of the organism among carcases being processed was followed qualitatively and, where appropriate, quantitatively.

3. The degree of cross‐contamination and the extent to which it could be controlled by the proposed measures varied from one site to another.     

Antibiotics for uncomplicated Salmonella enteritis: are they useful? A critical consideration of the literature

This article, a version of an earlier publication (6), reviews the human and veterinary literature on the effect of anti-microbials on uncomplicated Salmonella enteritis. The main conclusion is that there is no evidence for the widely held belief that anti-microbials prolong the time that salmonellae are shed.     

Assessment of producers’ response to Salmonella biosecurity issues and uptake of advice on laying hen farms in England and Wales

1. High standards of biosecurity are known to reduce the risk of disease outbreaks; however, uptake of advice and implementation of biosecurity measures are dependent on many factors.

2. This study assessed the uptake of targeted biosecurity advice by 60 laying hen farms provided during biosecurity audit visits. Advice was provided as bullet point cards focusing on specific areas identified as benefitting from improvement. These covered site entrance, site tidiness, vaccination, boot hygiene, hand hygiene, house tidiness, rodent control, fly control, red mite control and cleaning and disinfection between flocks. Background knowledge of Salmonella and biosecurity and farmers’ willingness and intent to implement additional measures were assessed.

3. About 50% of the principal decision-makers had basic background knowledge of Salmonella, with 22% considered well informed; almost all agreed that biosecurity could impact on Salmonella control and many appeared willing to implement additional biosecurity measures. Sixty-three per cent of study farms were categorised using the Defra Farmer Segmentation Model as Modern Family Businesses (MFBs), with 7–11% of farms being categorised as Custodian, Lifestyle Choice, Pragmatist or Challenged Enterprise; however, categorisation, did not determine uptake of advice. The most frequently used advice cards were boot hygiene, red mite control, hand hygiene, site entrance and cleaning and disinfection; uptake of advice ranged from 54 to 80% depending on the advice card.

4. Uptake of advice by the farmers was encouraging, especially considering it was being provided by people other than their usual source of biosecurity information. Those who did not implement the recommended measures cited cost, difficulty of enforcement and practicality as the main reasons. However, the positive uptake of advice and implementation of recommended measures by many farmers demonstrates that targeted advice, discussed face to face with farmers, on a small number of key areas, is a potentially effective method of providing biosecurity information to complement more lengthy formal advisory reports.     

In vitro screening of lactobacilli isolated from chicken excreta to control Salmonella Enteritidis and Typhimurium

1. The aim of this work was to select lactic acid bacteria (LAB) strains from chicks and hens of egg-laying strains for potential use to control Salmonellae.

2. Nineteen LAB strains obtained from culture collections, and 24 strains isolated from excreta of laying hens and chicks, were evaluated for inhibitory capacities against two Salmonella serotypes using a “Spot-the-lawn” technique and other in vitro properties that could be predictive of antimicrobial activity.

3. The size of the inhibition zone differed slightly between Salmonella serotypes, however, the mean size of the Salmonella inhibition zone differed greatly among the LAB strains. Lactobacillus salivarius, L. plantarum, L. rhamnosus and L. reuteri exhibited powerful inhibitory effects to each Salmonella strain.

4. The result of the acid tolerance test showed that all L. salivarius, L. kitasatonis strains and each of L. ingluviei cannot survive in a low pH environment. In the bile acid tolerance assay, growth was inhibited in all strains, except L. kitasatonis HE4, and a large inhibition was observed in most of the L. salivarius and L. crispatus strains.

5. The results demonstrate that some LAB of poultry origin were able to inhibit the growth of Salmonella and survive simulated passage through the gastrointestinal tract. The selected LAB could act in the lower gastrointestinal tract to prevent salmonellosis in poultry.     

Salmonella enteritis in dogs,not relevant?

In order to shed some light on the different opinions regarding the importance of Salmonella infections in dogs, we gathered some data from our laboratory database. Of the 6589 faecal samples from diarrhoeic dogs examined, 69 (1%) yielded Salmonella spp. Another eleven isolates were cultured from materials other than faeces. If Salmonella spp. can be cultured directly from faeces, this should be interpreted as clinically significant; however, even if the organism is found only after enrichment it may still be a clinical case. Antibiotic therapy is indicated in all dogs that are severely ill or have systemic infection, fluoroquinolones or trimethoprim/sulphonamides being drugs of choice. Double-blind placebo-controlled studies of humans with gastroenteritis have shown that the length of postconvalescent excretion of Salmonella is not affected by antimicrobials. For the elimination of the carrier state, however, fluoroquinolones are successful in human medicine. Salmonellae are zoonotic agents and transmission from dog to man has been reported. This should be taken into account when deciding on antimicrobial therapy. Of our isolates (n = 80), 96% were susceptible to enrofloxacin, 94% to trimethoprim/sulphonamides, 94% to gentamicin, 86% to ampicillin and amoxicillin-clavulanic acid, 47% to cephalexin and 63% to tetracycline.     

The contamination of winter stores and early spring honey with spores of Paenibacillus larvae larvae in Polish apiaries of the Małopolska province

We analysed 251 early spring and winter storage honey samples, individually collected from the apiaries of 9 districts of Malopo?ska province in South Poland and revealed that 51 of these specimens were contaminated with different levels of P. larvae larvae spores Among these samples 8.8% were classified as a category I contamination and 11.5% as a category II--reperesenting 22 (43.1%) and 29 (56.9%) of the total positives, respectively. We conclude from these analyses that: (1)--the total number of new outbreaks of AFB in Poland are most likely to be higher than previously reported, (2)--the quantitative examination of samples of winter stored or early spring honeys for the presence of P. larvae, larvae spores can improve the detection rate of AFB outbreaks, (3)--the high percentage of apiaries that were found to be free of P. larvae larvae (80%) may facilitate the implementation of an AFB eradication programme on a large scale in Poland.     

Phenotypic–genotypic resistance in Salmonella spp. isolated from cattle carcasses from the north central zone of the State of Mexico

Salmonella is a public and animal health problem due to the generation of strains multiresistant to antimicrobial products. The objective of this study was to determine prevalence and antimicrobial phenotypic and genotypic resistance of Salmonella spp. isolated from beef cattle carcasses killed in slaughterhouses of the north central zone of the State of Mexico. Sampling was carried out according to the European Directive 2001/471/EC; isolation and identification of the strain was carried out according to the Mexican Official Standard NOM-114-SSA1-1994; resistance was established by CMI according to the National Committees for Clinical Laboratory Standards (NCLS) and multiplex PCR according to Ahmed et al. (Journal of Applied Microbiology 106:402–409, 2009) with PSE-1, tetG, qnrS, FloR, STR, and sul1 oligonucleotides. Twenty-seven strains of Salmonella spp. were obtained from 327 samples (prevalence of 0.083); 19 strains (70 %) were resistant to 10 μg/ml of ampicillin, 15 of these (79 %) had the PSE-1 gene; 22 strains (84 %) were resistant to 30 μg/ml streptomycin, 14 of these (63.6 %) had the STR gene. Genes PSE-1 and STR were factors in the presence of resistance, the rest of the genes (tetG, qnrS, FloR, and sul1) were not factors of resistance in the studied strains.     

Molecular and phenotypic characteristics of CMY-2 β-lactamase-producing Salmonella enterica serovar Typhimurium isolated from cattle in Japan

Isolates of extended-spectrum cephalosporin (ESC)-resistant Salmonella enterica serovar Typhimurium obtained from two different farms in Fukushima Prefecture, Japan, in 2007 were characterized in order to determine the genetic basis of resistance. ESC resistance in the two isolates was mediated by an AmpC β-lactamase encoded by the bla(CMY-2) gene, which is located in a large self-transmissible plasmid in each isolate. The sizes of the bla(CMY-2)-carrying plasmids were different. The replicon types of the plasmids were I1-Iγ and A/C. The results of macrorestriction analysis and phage typing suggest a close relationship between both isolates. This is the first report of ESC-resistant S. Typhimurium isolated from cattle in Japan.