Avian colibacillosis caused by an intestinal pathogenic Escherichia coli isolate from calf diarrhea

An intestinal pathogenic Escherichia coli isolate from calf diarrhea, containing the iutA, f17A, afa-8D, and cnf2 genes, was able to cause avian colibacillosis after experimental infection in chickens. Intra-tracheal inoculation and spray of this strain caused 10% of mortality and gross lesions, including airsacculitis, pericarditis, and perihepatitis. These results suggest that some bovine pathogenic E. coli can cause extra-intestinal infections in other animal species.     

Effects and bioassay of Escherichia coli enterotoxin (heat-stable fraction) on smooth muscle

Heat-stable E. coli and V. cholerae enterotoxins and E. coli endotoxin were tested on the following smooth muscle preparation: vascular; rabbit aorta; rat mesenteric arterioles, and intestinal, rabbit jejunum; pig duodenum; dog jejunal lamina propria smooth muscle. The results indicated that in most preparations used, the prime action of heat-stable enterotoxin from pathogenic strains of E. coli consisted in neutralizing the effects of both alpha or beta adrenergic agonists. In this respect the effect of enterotoxin appeared similar to that of alpha or beta adrenergic blockers. Using the same models, it was found that this enterotoxin did not interfere with the effects of cholinergic agonists or of biogenic amines. Control heat-stable enterotoxin preparations and other tested substances proved inactive, suggesting that different receptor sites might exist for these agents in our models. It appears that smooth muscle preparations are well suited for bioassay of active heat-stable E. coli enterotoxin.     

The enteritis complex in domestic rabbits: A field study

A study of the causative agents of enteritis in domestic rabbits from 44 different accessions is described. In descending order of frequency, the organisms most commonly demonstrated were intestinal and hepatic coccidia (Eimeria species), Escherichia coli, Clostridium spp., Salmonella, Bacillus piliformis, and rotavirus. The species of Eimeria identified included those moderately pathogenic and coccidia of low pathogenicity. Using seven antisera against known enterpathogenic strains of E. coli, only one strain, O15, was identified in three cases. Clostridium perfringens or C. spiroforme was demonstrated in the intestinal contents in 11 cases, and lesions compatible with clostridial enteropathy were identified on gross and histopathology. In a serological survey, over 50% of 200 fryer rabbits submitted to Ontario abattoirs and of animals from commercial rabbitries had detectable antibody to rotavirus, indicating the widespread distribution of rotaviral infections in this species. In the cases of enteritis studied, two or more potentially pathogenic organisms were frequently identified, emphasizing that several different organisms may be acting in concert to produce clinical disease.     

Complex bacterial flora of imported pet tortoises deceased during quarantine: Another zoonotic threat?

Turtoises are a great puzzle when it comes to their bacterial flora, the composition and structure of which are still unknown in details. Its component which has been best described so far is Salmonella spp., presumably due to the threat of reptile-associated salmonellosis in humans. This investigation tried to assess and characterize intestinal bacterial flora of imported tortoises found dead during quarantine. Most of the animals carried various serovars of Salmonella showing no antimicrobial resistance. Presence of multiresistant Escherichia coli was possibly a result of industrial breeding and high usage of antimicrobials. Thirteen bacterial species or genera like Citrobacter spp., Morganella spp., Pseudomonas spp. were identified. Their commensal character is assumed, although pathogenic potential might be verified. The results indicate global tortoise trade as a source of common and exotic bacteria or antimicrobial resistance mechanisms in new geographical areas. These dangers indicate the need for a systematic survey of exotic pets and establishment of legal requirements for reptile health conditions on breeding, trade premises and in households with such pets.     

First insight into Encephalitozoon cuniculi infection in laboratory and pet rabbits in Iran

Encephalitozoon cuniculi infects a wide variety of domestic and wild mammalian species including humans. Although the infection status has been studied in laboratory and pet rabbits worldwide, there is shortage of information regarding the disease in Iran. In the present study, the occurrence of infection in brains of 117 asymptomatic rabbits from six breeding and experimental units with highest population of rabbit colonies in the country (n = 60) as well as pet rabbits of pet stores in two cities (n = 57) were examined by nested-PCR. Histological sections of brains and kidneys were also studied by light microscopy. PCR results revealed that 3.3% of laboratory rabbits (2/60) and 59.6% of pet rabbits (34/57) harboured E. cuniculi in their brains. Histopathology on the other hand showed spores of the parasite in kidney and brain of one and kidney of another pet rabbit. As encephalitozoonosis may interfere with results of experiments performed on laboratory rabbits, routine screenings for identification and culling of infected animals is recommended. Furthermore, infected companion rabbits can transmit E. cuniculi to people in close contact with them, therefore, improving public knowledge of this zoonotic infection is suggested.     

Isolation of Yersinia Enterocolitica from a Dog with Chronic Enteritis: A Case Report

During recent years, Yersinia enterocolitica has been isolated from humans and various animal species in connection with intestinal disorders, such as acute ileitis and appendicitis. Cases of septicaemia, polyarthritis and erythema nodosum have also been described (Mollaret & Destombes 1964, Nilehn 1969, Winblad 1969, Lassen 1972, Langford 1972). Y. enterocolitica has been isolated most frequently from chinchillas and hares, but sporadic isolations from deer, cow, horse, rabbit, goat and dog have been reported (Langford, Krogstad et al. 1972). In Norway, an outbreak of the disease in a goat herd is the only described case of yersiniosis among animal species (Krogstad et al.). A case of chronic enteritis in a dog from which Y. enterocolitica was isolated is presented in the following.     

Genetic variability of Eucoleus aerophilus from domestic and wild hosts

Eucoleus aerophilus (syn. Capillaria aerophila) is a trichuroid nematode affecting domestic and wild carnivores and, sometimes, humans. This parasite has a worldwide distribution and may cause significant clinical disease in pet animals. The present paper investigates the sequence variation in partial mitochondrial cytochrome c oxidase subunit 1 (cox1) gene of E. aerophilus isolates from pets and wild animals from different countries. Forty-four egg pools of E. aerophilus were collected from dogs, cats and foxes from Italy, while seventeen adult stages of E. aerophilus were obtained from red foxes and beech martens from Portugal, Romania, Serbia and UK. Fifteen different haplotypes were characterized and five were shared between pets in Italy and wildlife from Europe. The remaining haplotypes were either confined only in hosts or countries, or in a given host from a country. The phylogenetic analysis showed that all haplotypes clustered as a monophyletic group with a strong nodal support, indicating that all sequence types represented E. aerophilus. The results here presented have implications for a better understanding of the epidemiology, phylo-geography and clinical impact of E. aerophilus. In particular, the geographic distribution of E. aerophilus haplotypes in different host species and geographic regions, and their variation in terms of pathogenic impact and zoonotic role, warrant further investigations.     

Presence of Bacteria on the External Genitalia of Healthy Stallions and its Transmission to the Mare at the Time of Breeding by Live Cover

The current field study used thoroughbred stallions and mares from central Kentucky to investigate the occurrence of potentially pathogenic bacteria on the stallion's external genitalia, based on cultures, and investigated the occurrence of bacteria and type of isolate in the mare's uterus after breeding by live cover to stallions with or without positive bacterial cultures. Fifteen thoroughbred stallions and 206 mares from two central Kentucky thoroughbred farms were used during the 2010 and 2011 breeding seasons. Samples for bacteriological evaluation were taken from the prepuce and postejaculate urethra (n = 201) of stallions. Uterine swabs (n = 264) were collected 12-18 hours postbreeding. For statistical analyses, a chi-squared test was used to test the relationship between stallion culture results and postbreeding uterine culture results, as well as the effect of bacterial types found on the stallion cultures with bacterial types found on the postbreeding uterine cultures. Of stallion cultures, 22.4% were positive for potentially pathogenic bacteria, with Streptococcus equi subspecies zooepidemicus (51.1%) being the most common isolate. Uterine cultures resulted in a 29.2% positive rate for potentially pathogenic bacteria, with S. equi subsp. zooepidemicus (90.9%) being the most common. There was no difference (P > .05) in the occurrence of bacteria or type of isolate found on uterine cultures after breeding stallions with or without positive cultures. In conclusion, potentially pathogenic bacteria found on the stallion's external genitalia did not affect the occurrence and type of bacterial isolate found in the mare's uterus after breeding by live cover.     

Dietary non-starch polysaccharides alter the abundance of pathogenic clostridia in pigs

Some non-starch polysaccharides (NSP) promote the intestinal abundance of pathogenic Escherichia coli in pigs. However, their impact on pathogenic clostridia in the porcine intestinal tract is unknown. The present study aimed to determine the abundance of pathogens belonging to Clostridium clusters I and XI in faeces of growing pigs fed four semi-purified diets containing 5% of purified NSP differing in viscosity and fermentability (low-fermentable low-viscous cellulose; low-fermentable high-viscous carboxymethylcellulose; high-fermentable low-viscous oat β-glucan; and high-fermentable high-viscous oat β-glucan). For quantification of clostridial pathogens, toxin genes were determined using quantitative PCR. Clostridium perfringens α-toxin was detected in faeces of pigs fed low-fermentable cellulose and carboxymethylcellulose diets but was generally below detection limit for the two high-fermentable oat β-glucans. Clostridium botulinum toxin C2 was higher (P<0.05) by 0.7 to 0.9 log units in faeces of pigs fed the low-fermentable low-viscous cellulose diet than of pigs fed the other three diets. Clostridium difficile toxin B and Clostridium sordellii phospholipase C were not detected in pig faeces indicating that pigs were not colonized by these clostridial species belonging to Clostridium cluster XI. In conclusion, high-fermentable β-glucans decreased the faecal abundance of C. perfringens and, together with low-fermentable high-viscous CMC, that of C. botulinum in growing pigs when compared to low-fermentable low-viscous CEL. Besides fermentability, structural characteristics and indirect effects of NSP on nutrient flow into the large intestine may have played a role for the abundance of pathogenic clostridial species.     

Chemical composition of Eucalyptus spp. essential oils and their insecticidal effects on Lutzomyia longipalpis

The chemical composition of essential oils from three species of plants belonging to the Eucalyptus genus was determined and, their insecticidal effects on egg, larva and adult phases of Lutzomyia longipalpis were assessed. The insects were collected in the municipality of Sobral in the State of Ceará, Brazil. Five treatments with different concentrations were performed along with two negative controls, distilled water and Tween 80 (3%), and a positive control, cypermethrin (0.196 mg/ml). The tests were carried out in plastic pots internally coated with sterile plaster and filled with a substrate made of rabbit feces and crushed cassava leaves. The eggs, larvae and adults were sprayed with the oils. The hatched larvae were counted for 10 consecutive days and observed until pupation. Insect mortality was observed after 24, 48 and 72 h. E. staigeriana oil was the most effective on all three phases of the insect, followed by E. citriodora and E. globulus oils, respectively. The major constituents of the oils were Z-citral and alpha-citral (E. staigeriana), citronellal (E. citriodora) and 1,8-cineole (E. globulus). The Eucalyptus essential oils constitute alternative natural products for the control of L. longipalpis since the median effective concentration (EC₅₀) values revealed relevant action as compared with other natural products, some of their chemical constituents are already known for their insecticidal activity and these oils are produced in commercial scale in Brazil.     

Food animals as reservoirs and potential sources of multidrug-resistant diarrheagenic E. coli pathotypes: Focus on intensive pig farming in South Africa

BackgroundDiarrheagenic E. coli (DEC) strains are a major cause of diarrheal diseases in both developed and developing countries. Healthy asymptomatic animals may be reservoirs of zoonotic DEC, which may enter the food chain via the weak points in hygiene practices.AimWe investigated the prevalence of DEC along the pig production continuum from farm-to-fork.MethodsA total of 417 samples were collected from specific points along the pig production system, that is, farm, transport, abattoir and food. E. coli was isolated and enumerated using Colilert. Ten isolates from each Quanti-tray were selected randomly and phenotypically identified using eosin methylene blue agar selective media. Real-time polymerase chain reaction (PCR) was used to confirm the species and to classify them into the various diarrheagenic pathotypes. Antimicrobial susceptibility was determined against a panel of 20 antibiotics using the Kirby-Bauer disk diffusion method and EUCAST guideline.ResultsThe final sample size consisted of 1044 isolates, of which 45.40% (474/1044) were DEC and 73% (762/1044) were multidrug-resistant. Enteroinvasive E. coli (EIEC) was the most predominant DEC at all the sampling sites.ConclusionThe presence of DEC in food animal production environments and food of animal origin could serve as reservoirs for transmitting these bacteria to humans, especially in occupationally exposed workers and via food. Adherence to good hygienic practices along the pig production continuum is essential for mitigating the risk of transmission and infection, and ensuring food safety.     

Antimicrobial resistant Escherichia coli in the reproductive tract microbiota of cows and sows

Escherichia coli is a natural colonizer of the urogenital mucosa of healthy females; however it is one of the pathogens associated to reproductive failures in cows and sows. A better knowledge about the characteristics of native E. coli will allow us to differentiate them from pathogenic strains. Ninety autochthonous isolates from the reproductive tract of sows and cows were characterized to determine the phylogenetic profile, antibiotic resistance and virulence factors; also, comparisons between different breeding systems were performed. Vaginal colonization of E. coli was statistically higher in cows (57.5%) than sows (23.8%), and most isolates belonged to the phylogenetic group A: 79.69 and 80.77%, respectively; moreover phylo-groups B1 (12.5 and 11.54%) and D (7.81 and 7.69%) were significantly lower; however, none was classified as B2. Positive associations between virulence factors and group D were found. Isolates with antimicrobial susceptibility were associated with group A and the MDR (Multiple Drug Resistance) was related to the porcine source. These results contribute to the knowledge of extra-intestinal E. coli populations; which could affect the reproductive performance of females.     

Combining information from surveys of several species to estimate the probability of freedom from Echinococcus multilocularis in Sweden,Finland and mainland Norway

Background

The fox tapeworm Echinococcus multilocularis has foxes and other canids as definitive host and rodents as intermediate hosts. However, most mammals can be accidental intermediate hosts and the larval stage may cause serious disease in humans. The parasite has never been detected in Sweden, Finland and mainland Norway. All three countries require currently an anthelminthic treatment for dogs and cats prior to entry in order to prevent introduction of the parasite. Documentation of freedom from E. multilocularis is necessary for justification of the present import requirements.

Methods

The probability that Sweden, Finland and mainland Norway were free from E. multilocularis and the sensitivity of the surveillance systems were estimated using scenario trees. Surveillance data from five animal species were included in the study: red fox (Vulpes vulpes), raccoon dog (Nyctereutes procyonoides), domestic pig, wild boar (Sus scrofa) and voles and lemmings (Arvicolinae).

Results

The cumulative probability of freedom from EM in December 2009 was high in all three countries, 0.98 (95% CI 0.96-0.99) in Finland and 0.99 (0.97-0.995) in Sweden and 0.98 (0.95-0.99) in Norway.

Conclusions

Results from the model confirm that there is a high probability that in 2009 the countries were free from E. multilocularis. The sensitivity analyses showed that the choice of the design prevalences in different infected populations was influential. Therefore more knowledge on expected prevalences for E. multilocularis in infected populations of different species is desirable to reduce residual uncertainty of the results.     

All blood, No stool: enterohemorrhagic Escherichia coli O157:H7 infection

Enterohemorrhagic Escherichia coli serotype O157:H7 is a pathotype of diarrheagenic E. coli that produces one or more Shiga toxins, forms a characteristic histopathology described as attaching and effacing lesions, and possesses the large virulence plasmid pO157. The bacterium is recognized worldwide, especially in developed countries, as an emerging food-borne bacterial pathogen, which causes disease in humans and in some animals. Healthy cattle are the principal and natural reservoir of E. coli O157:H7, and most disease outbreaks are, therefore, due to consumption of fecally contaminated bovine foods or dairy products. In this review, we provide a general overview of E. coli O157:H7 infection, especially focusing on the bacterial characteristics rather than on the host responses during infection.     

Breeding Bird Use of Production Stands of Native Grasses—a Working Lands Conservation Approach

Grassland birds have experienced protracted population declines, primarily due to loss and degradation of native grasslands. Restoration of native grasses may benefit grassland birds, but such restoration within the eastern United States has been limited. Production uses of native grasses (e.g., hay, pasture, biofuel feedstock) provide market-based incentives that could lead to more extensive use of these grasses than existing conservation-focused practices, potentially influencing breeding birds. Therefore, we compared breeding bird (n = 9 target species) relative abundance among 4 types of native warm-season grass (NWSG) agricultural production fields: forage (hay and pasture; n = 22 and 7, respectively), seed (n = 21), biofuel (n = 15), and a control (idle fields in conservation programs or practices; n = 37) in Kentucky and Tennessee, 2009–2010. We detected 2 145 birds, with field sparrow (Spizella pusilla, 43%) and red-winged blackbird (Agelaius phoeniceus, 27%) encountered most often. Relative abundance did not differ between production types and controls except for field sparrow (lower on seed production fields) and northern bobwhite (Colinus virginianus, lower on hay production fields). Species richness equaled or exceeded that of control fields for all production categories. We documented negative relationships between relative abundance and landscape-scale forest cover for four species (field sparrow, grasshopper sparrow [Ammodramus savannarum], eastern meadowlark [Sturnella magna], and red-winged blackbird) and positive relationships with amount of pasture and hay cover for four species (northern bobwhite, grasshopper sparrow, eastern meadowlark, and red-winged blackbird), reinforcing the importance of nonforested environments for these species. We conclude that production stands could be a viable approach for increasing NWSG available for breeding birds and, when established in the appropriate landscape context, can provide benefits similar to those provided by conservation programs.     

Identification of porcine Serpulina strains in routine diagnostic bacteriology

Serpulina strains from pigs were identified using simple tests. The large size of S. hyodysenteriae in stainings from colonic contents and faeces was found useful for the presumptive differentiation of this major pathogenic species from the other Serpulinae. However, this morphological characteristic gets lost upon cultivation. The `ring phenomenon' aided to confirm the strong haemolysis typical for S. hyodysenteriae. The weakly haemolytic species S. innocens, S. pilosicoli, S. intermedia and S. hyodysenteriae could be differentiated with the help of the indole spot test and two or four other simple enzymatic tests. Nearly half of the S. hyodysenteriae strains isolated in Belgium were indole-negative. Such strains have only rarely been reported earlier, and were absent among the strains from other European countries examined.     

Effect of fosfomycin,Cynara scolymus extract,deoxynivalenol and their combinations on intestinal health of weaned piglets

Weaning is a challenging stage of pig farming. Animals undergo environmental, social and dietary changes leading to weaning stress syndrome. In order to compensate for the detrimental effects of weaning stress, antibiotics and natural extracts are used as feed additives, sometimes without fully understanding the interactions between them or even with low concentrations of mycotoxins that are frequently present in feed. The aim of this study was to evaluate the effect of fosfomycin (FOS), Cynara scolymus extract (CSE), deoxynivalenol (DON) and their combined administration on intestinal health of weaned piglets. The experiment was designed as a 2 × 2 × 2 factorial arrangement with 3 factors (FOS, CSE and DON treatments), 2 levels each (presence and absence) and 3 repeats. Weaned piglets (n = 24) were randomly divided in groups to receive the different treatments, namely DON administered in diet (50 μg/kg BW), FOS administered into the drinking water (30 mg/kg BW), CSE administered in diet (15 mg/kg BW) and all their combinations. After 15 d, the animals were euthanized and gastrointestinal tract samples were immediately taken to evaluate gastrointestinal pH, Enterobacteriaceae to lactic acid bacteria (E:L) ratio, volatile fatty acid (VFA) concentrations, disaccharidase (lactase, sucrase and maltase) activity, histology (intestinal absorptive area [IAA] and goblet cells count) and mucus ability to adhere pathogenic Escherichia coli. From our results, FOS and CSE treatments, individually or combined, produced a lower E:L ratio, an enhanced production of butyrate, increased disaccharidase activity (particularly maltase), and a greater IAA and goblet cells count along with an increase in pathogenic bacteria adherence to intestinal mucus. Deoxynivalenol did not show interactions with the other factors and its administration produced decreases on VFA, disaccharidase activity and goblet cells count. In conclusion, weaning piglets receiving diets containing FOS, CSE or both exhibited evident beneficial intestinal effects compared to animals receiving diets free from these compounds. On the contrary, the presence of DON at sub-toxic concentrations produced detrimental effects on intestinal health. The knowledge of the physiological and pathological gut changes produced by these compounds contributes to understand their potential productive consequences.     

Detection and genotypic differentiation of Campylobacter jejuni and Campylobacter coli strains from laying hens by multiplex PCR and fla-typing

In total, 26 Campylobacter (C.) strains, isolated from liver, spleen, caecal or jejunal content of laying hens from different flocks were examined. In these flocks a drop in egg production, an increasing mortality and livers with whitish-grey lesions as post-mortem finding were observed. Suspected Campylobacter colonies were differentiated using a modified m-PCR in 13 Campylobacter jejuni and 13 Campylobacter coli strains. All isolates were characterised by typing of the flaA and flaB gene each with two restriction enzymes. To compare the four different profiles for all strains an artificial “fla-type” was generated. Different and identical fla-types of C. jejuni and C. coli were recovered from both intestinal and extra-intestinal organs of the laying hens and even from individual birds. One significant observation is that some fla-types of C. jejuni or C. coli were detected in intestinal and systemic sites but not all fla-types of both species appeared to be equally able to invade internal organs.     

Essential role of neutrophils but not mammary alveolar macrophages in a murine model of acute Escherichia coli mastitis

Mastitis, the inflammation of the mammary gland, is an important disease affecting dairy animals worldwide. The disease is caused by mammary pathogenic bacteria and Escherichia coli are frequently implicated. Virulence factors of mammary pathogenic E. coli are only partially known and intramammary challenge with LPS elicits neutrophil recruitment in experimental bovine and murine mastitis models. We have previously shown that neutrophil recruitment in LPS-induced murine mastitis is strictly dependent on mammary alveolar macrophages. However, the relative role of alveolar macrophages and blood neutrophils in E. coli mastitis is not well defined. To this end, we selectively depleted mammary alveolar macrophages or blood neutrophils before intramammary challenge with E. coli strain P4 (ECP4). Mice depleted of alveolar macrophages prior to intramammary challenge recruited neutrophils normally and restricted bacterial growth and interstitial invasion. Importantly however, upon depletion of alveolar macrophages, ECP4 invaded the mammary alveolar epithelial cells and formed intracellular bacterial communities. In contrast, neutrophil depletion prior to intramammary infection with ECP4 was associated with unrestricted bacterial growth, tissue damage, severe sepsis and mortality. This study suggests that neutrophils but not alveolar macrophages provide essential antimicrobial defense against mammary pathogenic E. coli. Furthermore, we show here similar invasion after depletion of alveolar macrophages as in our previous studies showing that LPS/TLR4 signaling on alveolar macrophages abrogates ECP4 invasion of the mammary epithelium. Interestingly, similar ECP4 invasion and formation of intracellular communities were also observed following intramammary infection of either iNOS gene-deficient or IL-1 receptor type 1 gene-deficient mice.