Phylogenetic background of attaching and effacing <Emphasis Type="Italic">Escherichia coli</Emphasis> isolates from animals

Detection and distribution of eae gene in forty-four attaching and effacing Escherichia coli (AEEC) strains of animal origin were investigated. Association of distinct intimin alleles with phylogenetic background were assessed among strains in comparison with different serogroups. Phylogenetic analysis showed that 31 EHEC/eae+ STEC strains belong to groups A, B1 and E, 13 EPEC strains segregated in B1 and B2. Moreover, group A possessed the eae gamma2/theta type, group B1 the eae beta1, eae kappa, eae zeta, and eae epsilon types, group B2 the eae alpha1, eae alpha2 and eae iota types, while the group E possessed the eae gamma1 type. The presence of numerous eae-types show that EPEC and EHEC/eae+ STEC tested have a high genetic homology within each phylogenetic group.     

Epidemiological survey on <Emphasis Type="Italic">Escherichia coli</Emphasis> O157 in Chongqing and Three-Gorge Reservoir Areas of China

Prevalence, presence of virulence and adherence associated genes, genetic diversity, biochemical characteristics, and antibiotic susceptibility were determined for Escherichia coli O157 isolated over 4 months in Chongqing city and Three-Gorge Reservoir Areas. 11 isolates of E. coli O157 were isolated from 1504 samples and 7 of them are O157:H7 and 4 are O157:H? All O157:H7 isolates had eaeA, ehxA, EspA and Tccp genes, but did not have stx1 and stx2. All O157:H? isolates did not have stx1, stx2, eaeA, ehxA, EspA and Tccp genes except for the isolate obtained from Yunyang county which had stx1. When eaeA and ehxA presented in isolates were digested by restriction enzymes, the numbers and the sizes of the segments were the same as the control E. coli O157 strains. This suggests that eaeA and ehxA exhibit poor polymorphism. Most E. coli O157 isolates showed identical biochemical activities to the standard strains for sorbitol and rhamnose, and all E. coli O157:H7 obtained from feces at the same dairy cattle farm had similar biochemical characteristics. Antibiotic susceptibility demonstrated resistance of the isolates to penicillin, ampicillin, bacitracin, cefuroxime, erythromycin, gentamycin and tetracycline, indicating the isolates obtained in this study had a multi-drug resistance.     

<Emphasis Type="Italic">Theileria</Emphasis> (<Emphasis Type="Italic">Babesia</Emphasis>) <Emphasis Type="Italic">equi</Emphasis> and <Emphasis Type="Italic">Babesia caballi</Emphasis> Infections in Horses in Galicia,Spain

The control of equine piroplasmosis is becoming increasingly important to maintain the international market open to the horse industry. The purpose of this study was to demonstrate the occurrence of equine piroplasmosis (Theileria equi and Babesia caballi) in Galicia, north-west Spain, and to compare haematological and serum biochemistry parameters between non-parasitaemic horses and horses parasitaemic with T. equi and B. caballi. Sixty serum samples (control group) were taken from healthy horses pastured on two farms, and examined for evidence of equine T. equi and B. caballi infection by indirect fluorescent antibody test (IFAT). Of the 60 samples, 24 (40%) and 17 (28.3%) samples were positive for T. equi and B. caballi, respectively. Twelve (20%) samples were positive for both parasites. Haematology and serum biochemistry were compared between controls and a series of 36 horses clinically affected by T. equi (25) or B. caballi (11). Compared with the healthy group, there was a 43% and 37% decrease in the haematocrit for T. equi and B. caballi infection, respectively. Parasitaemic horses presented an intense anaemia and serum biochemistry signs of liver damage. The anaemia was more severe in T. equi-infected than in B. caballi-infected horses. Our results suggest that equine piroplasmosis is widespread in the region and is a cause for concern.     

Pathological,serological, and virological findings in sheep infected simultaneously with <Emphasis Type="Italic">Bluetongue</Emphasis>, <Emphasis Type="Italic">Peste-des-petits-ruminants</Emphasis>, and <Emphasis Type="Italic">Sheeppox viruses</Emphasis>

In this study, pathological, serological and virological examinations were performed on 15 sheep from a flock of 250 sheep and lambs that suffer from simultaneous naturally occurring BTV, PPRV and SPV outbreaks. SPV was diagnosed macroscopically and histopathologically, BTV was diagnosed by ELISA, and PPRV was diagnosed pathologically and by ELISA. Clinically fever, diarrhea, depression, polypnea, conjunctivitis, lacrimation, rhinitis, erosive stomatitis, edema of eyelids, photophobia, cutaneous eruption with erythematous areas especially noticeable in wool-free parts of the body and axilla lesions evolving into papules were observed. At necropsy, the most effected organs were lungs and gut. Subepicardial hemorrhages were also commonly seen. While typical pox lesions were observed in some lambs, usually fibrinous pleuropneumonia was more prominent lung lesion. SPV and PPRV lesions were seen at the histopathological examination of the lesioned tissues, BT lesions were mild than SPV and PPRV microscopically. Serum and leukocyte samples of 15 animals were examined for PPRV and BTV by ELISA; 5 samples were positive for PPRV and 6 BTV, 4 were positive for both PPRV and BTV simultaneously. One hundred animals died, most were lambs. Mortality rates were 100% in lambs and 80% in the herd.     

Host Switch of <Emphasis Type="Italic">Lamellodiscus elegans</Emphasis> (Monogenea: Monopisthocotylea) and <Emphasis Type="Italic">Sparicotyle chrysophrii</Emphasis> (Monogenea: Polyopisthocotylea) between Cage-reared Sparids

Sharpsnout bream (Diplodus puntazzo) has been used in Adriatic aquaculture for less than a decade, but the decreasing trend of rearing this species will probably result in its complete substitution by more exploited sea bream (Sparus aurata). Only two facilities still rear both fish species in neighbouring cages in monoculture. A switch of parasites was observed between sparids during monitoring of the gill monogeneans of farmed fish. In wild fish of the Adriatic Sea, Lamellodiscus elegans (Monogenea: Monopisthocotylea) has previously been reported in annular (Diplodus annularis), and two-banded sea bream (D. vulgaris) and sharpsnout bream (D. puntazzo), and the present study confirmed its presence also in sea bream, in low prevalence and abundance. The exclusively sea bream monogenean Sparicotyle chrysophrii (Monogenea: Polyopisthocotylea) was also isolated from sharpsnout bream, showing prevalence and abundance values even higher than in its resident host. In the occurrence of L. elegans in sea bream, the opportunistic switch resulted in lower abundance and prevalence than in the original host, while in the second case of switching the monogenean S. chrysophrii showed better reproductive capacity on a new host (sharpsnout bream). Both cases point to the possible enlargement of parasite host range.     

Investigation of seroprevalence of <Emphasis Type="Italic">Theileria equi</Emphasis> and <Emphasis Type="Italic">Babesia caballi</Emphasis> in horses in Nigde province,Turkey

The prevalence of equine piroplasmosis caused by Theileria equi and Babesia caballi in Nigde, in central Anatolia, Turkey has remained unknown. Serum samples were obtained from a total of 125 horses and were tested for antibodies to T. equi and B. caballi using the Indirect Fluorescence Antibody Test (IFAT). Twenty-three (18.4%) horses were seropositive for equine piroplasmosis. Anti-T. equi was observed in 16 horses (12.8%) while anti-B. caballi was detected in 12 horses (9.6%). In addition, 5 serum samples were positive for both parasites. The prevalence rates of antibodies to T. equi and B. caballi for female and male horses were statistically indifferent (p = 0.19 and 0.90). The difference between the seropositivity rates to T. equi among age groups was statistically insignificant (p = 0.44) while the difference to B. caballi among age groups is statistically significant (p = 0.01). Seropositivity rates ranged from 2.9% to 25.7% for T. equi and 2.9% to 14.3% for B. caballi from the selected districts in Nigde. A statistically significant difference on seropositivity rates for the study sites was observed for only T.equi (p = 0.03). This study indicates that T. equi is higher than B. caballi in Nigde. This study was supported by the Scientific Research Projects Unit of Nigde University (FEB 2007/08).     

Risk factors for <Emphasis Type="Italic">Mycobacterium avium</Emphasis> subspecies <Emphasis Type="Italic">paratuberculosis</Emphasis> in Fars province (Southern Iran) dairy herds

A cross-sectional study was conducted from March to August 2006 in dairy herds in Fars province, southern Iran to determine the herd-level risk factors for infection with Mycobacterium avium subspecies paratuberculosis (MAP). Statistical analysis using multivariable logistic regression showed that contamination of udders of periparturient cows with manure (OR = 6.4, P = 0.02) and history of having suspected cases of Johne's disease in the herd (OR = 6.7, P = 0.04) were significantly associated with the herd infection status. No relationship between breed, herd size and other management practices with the infection status of the herd were found in this study. Implementing high sanitary measures in the farm, particularly with respect to manure handling and cleaning could be considered as one of the important aspects in controlling disease in the region as well as in the future educational effort.     

Prevalence of <Emphasis Type="Italic">Toxoplasma gondii</Emphasis> and <Emphasis Type="Italic">Neospora caninum</Emphasis> infections in sheep from Federal District,central region of Brazil

Serum samples from 1028 sheep were collected from 32 herds within Federal District, in the central region of Brazil. The samples were examined by indirect fluorescent antibody test (IFAT) using sera diluted 1:64 and 1:50 as cut-off values for the detection of antibodies against Toxoplasma gondii and Neospora caninum, respectively. The observed prevalence for T. gondii infection was 38.22% (26.81%<CI 0.95<49.62%), and the titers ranged from 64 to 65536. The observed prevalence for N. caninum infection was 8.81% (7.08%<CI 0.95<10.53%). The titers ranged from 50 to 51200. The reactant sera to both pathogens corresponded to 4.67% of the samples. The risk factors were not determined because of the absence of negative herds for T. gondii and the high proportion of positive herds for N. caninum (87.50%). The prevalence for T. gondii infection was significantly higher among males than in females. The present work is the first report on seroprevalence of T. gondii and N. caninum in sheep from Federal District and shows that infection by both parasites is widespread in the ovine population from this region.     

Reduction of <Emphasis Type="Italic">Theileria annulata</Emphasis> Infection in Ticks Fed on Calves Immunized with Purified Larval Antigens of <Emphasis Type="Italic">Hyalomma anatolicum anatolicum</Emphasis>

Larval antigen of Hyalomma anatolicum anatolicum, the vector of Theileria annulata, was purified by two-step affinity chromatography using anti-tick gut-specific rabbit IgG and IgG from immunized cattle. The purified antigen showed the presence of a single polypeptide of 37 kDa (GHLAgP) on SDS-PAGE. Two groups (I and II) of naive crossbred calves (Bos taurus × B. indicus) were immunized with 1 mg of GHLAgP in three divided doses. Immunized calves of group I were also infected with a sublethal dose of T. annulata along with a group of non-immunized calves (group III). Animals in groups I, II, III as well a control group (group IV) were challenged with live nymphs of H. a. anatolicum on the 10th day of immunization. There was a significant reduction in the number of emerging adults of 56.9% ± 1.67% in calves of group I (p < 0.01) and 63.09% ± 1.26% in calves of group II (p < 0.001) compared to the controls. The calves of groups I and II showed antibody responses to tick antigen up to day 70 post immunization. Infection with T. annulata was determined in the salivary glands of adult ticks that developed from the nymphs used for challenge infection. In ticks taken from group I calves, there was a 75.0% ± 0.00% infection compared with only 85.0% ± 2.88% infection in ticks taken from calves of group III. Using PCR, a lower infection (83.33% ± 3.33%) was detected in ticks that developed from calves of group I compared with calves from group III (90.00% ± 2.88%). The ground-up tick supernatants (GUTS) of the ticks taken from calves of group III yielded higher infection rate and exhibited higher infectivity titre in in vitro infection assay of bovine mononuclear cells than the GUTS of the ticks taken from calves of group I. The results suggest a partial reduction in growth rate of T. annulata in ticks feeding on calves immunized with GHLAgP.     

A Single-chain Fragment Variable Recombinant Antibody against F5 Fimbria of Enterotoxigenic <Emphasis Type="Italic">Escherichia coli</Emphasis> Inhibits Agglutination of Horse Red Blood Cells Induced by F5 Protein

Bovine colibacillosis caused by enterotoxigenic Escherichia coli (ETEC) is a worldwide problem. Adhesion of ETEC to intestinal cell receptors mediated by the surface protein F5 fimbriae is the initial step in the establishment of colibacillosis. Prevention of ETEC F5⁺ adhesion to enterocytes protects newborn calves against collibacillosis. On the enterocytes, the F5 fimbriae bind to a ganglioside that is also found on horse red blood cells. Thus, the presence of F5 fimbriae induces haemagglutination, which is useful as an indicator in a functional assay system. In this study, recombinant anti-F5 scFv antibody fragment produced in E. coli HB2151 reacted with F5 fimbriae in ELISA and Western immunoblot, and prevented haemagglutination induced by the binding of the F5 fimbriae to its natural host receptors on horse red blood cells. Given the ease with which recombinant antibodies can be mass-produced, the presently described scFv may hold promise as a prophylactic agent for colibacillosis.     

Immunopathology of <Emphasis Type="Italic">Dirofilaria immitis</Emphasis> Infection

Heartworm disease caused by Dirofilaria immitis affects canine and feline hosts, with infections occasionally being reported in humans. Studies have shown that both dirofilarial antigens and those derived from its bacterial endosymbiont Wolbachia, interact with the host organism during canine, feline and human infections and participate in the development of the pathology and in the regulation of the host’s immune response. Both innate and acquired immune responses are observed and the development of the acquired response may depend on the host and, or on its parasitological status. This review aims at illustrating current research on the role of both D. immitis and Wolbachia, in the immunology and immunopathology of dirofilariosis.     

Economic Contribution of Draught Animals to <Emphasis Type="Italic">Mazahua</Emphasis> Smallholder <Emphasis Type="Italic">Campesino</Emphasis> Farming Systems in the Highlands of Central Mexico

The economic contribution of draught animals to smallholder Mazahua campesino systems in two mountain villages of San Felipe del Progreso, in the central highlands of Mexico, was assessed. Campesinos rely on draught animals for cultivation tasks, as pack animals, and as transport for agricultural and domestic activities. The villages were San Pablo Tlalchichilpa (SPT) and La Concepción Mayorazgo (LCM). Twelve households that possessed draught animals were monitored from July 1999 to June 2000, nine in SPT and three in LCM, in terms of animal inventories and income from their draught animals, in cash and opportunity values. Equines in SPT have substituted bulls, and are recognized for their multipurpose contribution, while in LCM bulls are still used for ploughing the land. Overall total mean gross income was US$490.78 per farm per year, plus US$56 as opportunity value of the fertilizer value of manure for both villages. Deducting estimated costs, owning draught animals leaves a mean net margin of US$412.50/year in SPT and of US$285.64/year in LCM. There is a significant correlation (p < 0.05) between ownership of draught animals and incomes, with a regression coefficient of US$279.16 per year per draught animal. Besides positive economic returns, having work animals alleviates drudgery for the campesino families.     

Isolation of <Emphasis Type="Italic">Vagococcus salmoninarum</Emphasis> in Rainbow Trout, <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis> (Walbaum), Broodstocks: Characterization of the Pathogen

Coldwater ‘streptococcosis’, caused by Vagococcus salmoninarum, is an emerging disease of rainbow trout in the European Union, causing mortality rates up to 50% in broodstock during the spawning period, with water temperature of 10–12°C. A study to determine the presence and role of this bacterium was undertaken using classical bacteriological techniques confirmed with polymerase chain reaction. This is the first report of isolation of V salmoninarum in relation to outbreaks of mortality in a rainbow trout farm devoted exclusively to broodstock rearing in Spain. A total of 10 isolates of V salmoninarum were characterized by their morphological, cultural, physiological, biochemical and enzymatic traits. Some differences were observed in parameters such as growth on MacConkey agar, H2S production, acid production from starch, and some other minor variations. Isolates were sensitive to erythromycin and oxytetracycline tested in vitro, but treatments conducted in the field were ineffective. An attempt at vaccination did not provide encouraging results.     

Genotyping of <Emphasis Type="Italic">Chlamydophila psittaci</Emphasis> strains derived from avian and mammalian species

Eleven Chlamydophila (formerly Chlamydia) psittaci strains derived from avian and mammalian species (two from dairy cows, one from duck, three from sheep, three from wild birds, and two from pigs) were identified as genotype C by outer membrane protein A gene sequencing. Genotype C had been preferentially associated with waterfowl. This paper suggests that mammals may represent an underestimated source for genotype C strains and for human psittacosis cases.     

Stimulation of the <Emphasis Type="Italic">In Vitro</Emphasis> Migration of Ovine Eosinophils by Factors Derived from the Sheep Scab Mite, <Emphasis Type="Italic">Psoroptes ovis</Emphasis>

The ectoparasitic astigmatid mite Psoroptes ovis causes sheep scab, a highly contagious, severe allergic dermatitis associated with damage to the fleece and hide, loss of condition and occasional mortality. The scab lesion is characterized by a massive infiltration of eosinophils that begins very rapidly after infection. This paper reports the finding that mite-derived factors directly enhance the migration of ovine eosinophils in vitro. Significant (p < 0.01) and dose-dependent (r = 0.972 ± 0.018 (SD)) activity was initially identified in whole mite extracts, by comparison with medium controls in an assay based on modified Boyden chambers and ovine bone marrow target cells. Similar pro-migratory activity (p < 0.005; r = 0.928 ± 0.069 (SD)) was detected in washes containing mite excretory/secretory material. By direct comparison with migration ratios (n = 3) for defined chemotactic (rmeotaxin = 3.430 ± 0.360 (SD)) and chemokinetic (rminterleukin-5 = 0.982 ± 0.112 (SD)) stimuli it was determined that the activity in both mite extracts (0.992 ± 0.038 (SD)) and mite washes (0.969 ± 0.071 (SD)) was chemokinetic. Subsequent experiments (n = 3) in which live mites were incorporated directly into the in vitro assay system indicated that they produced factors that significantly (p < 0.001) enhanced eosinophil migration to a degree directly related to mite numbers (r = 0.993 ± 0.005 (SD)). The identity of the factor(s) responsible is uncertain, but their presence suggests that mites may be capable of directly activating eosinophils in vivo, and raises the possibility that mites could directly influence, perhaps even initiate, the rapid early tissue eosinophilic response observed in experimental sheep scab infections.     

Sheep performance under intensive continuous grazing of native grasslands of <Emphasis Type="Italic">Paspalum notatum</Emphasis> and <Emphasis Type="Italic">Axonopus compressus</Emphasis> in the subtropical region of the Highlands of Central Mexico

Liveweight gain was evaluated in tropical Dorper X Pelibuey lambs under intensive continuous grazing of native grasslands dominated by Paspalum notatum (PN) or Axonopus compressus (AC) in the subtropics of Central Mexico. Two trials were undertaken. Trial 1 lasted 12 weeks with 10 lambs (initial weight 18 +/- 2.57 kg, 3 months old) per treatment in 2002, and Trial 2 for 13 weeks with 8 lambs (initial weight 24.0 +/- 2.0 kg, 4 months old) per treatment. Lambs were weighed once per week, and liveweight change was estimated by linear regression over day of the experiment, using individual regression coefficients as unbiased estimates of daily liveweight change; analysed in a random block design. Lambs on Trial 1 gained 0.061 kg/lamb/day on PN and 0.047 kg/lamb/day on AC (P > 0.05) at an overall mean stocking rate of 25 lambs/ha. In Trial 2, liveweight gain was significantly larger in PN (0.060 kg/lamb/day) than on AC (0.043 kg/lamb/day) (P < 0.05), at a mean stocking rate of 21.5 lambs/ha. It is concluded that intensive continuous grazing of native grasslands in the subtropics of the highlands of Central Mexico enables moderate liveweight gains for weaned lambs during the rainy season; with better results in grasslands dominated by Paspalum notatum.