Sílvia Regina Leal Ladeira

Campylobacter jejuni occurrence in chicken fecal samples from small properties in Pelotas, southern of Brazil

The aim of this study was to evaluate the occurrence of thermophilic Campylobacter species in broiler flocks from 26 small properties located near the campus of Federal University of Pelotas, RS, Brazil. A total of 404 chicken fecal samples were analyzed and after isolation, identification and biotyping was performed according

Abortos em equinos na região sul do Rio Grande do Sul: estudo de 72 casos

A retrospective study of the causes of equine abortion occurred in southern Rio Grande do Sul, Brazil, diagnosed from January 2000 to June 2011 by the Regional Diagnostic Laboratory (LRD) of the Veterinary School, Federal University of Pelotas (UFPel), is reported. Necropsy protocols were reviewed, and from 1.154 horses or equine materials received 72 (6.2%) were abortions. The main cause of abortion in this study was bacterial infection on 36.1% of the cases. Non-infectious causes accounted for 8.3% of the cases, viral abortions for 4.2%, parasitic for 1.4% and inflammatory for 2.8%. In 47.2%, it was not possible to determine the cause/etiology of abortions. Characteristic macroscopic and histological lesions were observed in abortion by Leptospira sp. and equine herpesvirus-1. No lesions were observed in the other cases. It was demonstrated that the analyses of whole fetus with the placenta under refrigeration increases the efficiency of diagnosis. The high number of abortions of undetermined cause was attributed in part to inadequate delivery of fetus material for diagnoses.

Role of Pasteurella granulomatis and Dermatobia hominis in the Etiology of Lechiguana in Cattlea

Attempts were made to reproduce bovine lechiguana, a disease associated with Dermatobia hominis and Pasteurella granulomatis infections. Suspensions of Pasteurella granulomatis were mixed with each of the following: saponin, oil adjuvant, ground Dermatobia hominis, or 5% mucin. Each preparation was inoculated into 6 cattle. Twelve more cattle, 6 of which received dexamethasone, were inoculated with bacterial suspension alone. Abscesses but no lechiguana was produced in all 36 cattle. After abscess regression, 12 cattle were reinoculated with a suspension of mouse-passed P. granulomatis. Only abscesses were produced. The intralymphatic inoculation of P. granulomatis in 6 cattle did not produce the disease. Eleven cattle infected naturally with D. hominis had lesions containing dead larvae. These lesions were inoculated with P. granulomatis. Nine cattle were experimentally infected with larvae of D. hominis that had been contaminated with the bacteria. No lechiguana lesions were produced in these 20 cattle. Six cattle with severe natural D. hominis infection were inoculated in the larval lesions with P. granulomatis. One developed lesions indistinguishable from those of natural lechiguana. The lesions regressed after treatment with chloramphenicol. D. hominis larvae and exudate from lesions caused by the fly were collected from 7 cattle on 3 farms and examined bacteriologically. P. granulomatis was isolated from the larvae and the exudate of a healthy calf from a farm where lechiguana had never been observed. These results suggest that P. granulomatis has a causal role in lechiguana, and that D. hominis may be a carrier of the bacterium. These observations suggest that lechiguana occurs when severe D. hominis lesions are infected with P. granulomatis. The apparent long incubation period, the negative results obtained in the other experiments, and also the infrequent occurrence of the natural disease suggest that lechiguana is a disease for which Kochs postulates are not easily fulfilled.

Anthrax in cattle in southern Brazil: 1978-2006

Ten outbreaks of anthrax occurred in cattle from 1978 to 2006 in southern Brazil, in 5 municipalities on the border with Uruguay, a country where the disease is frequent. The 10 outbreaks represented 0.2% of all bovine specimens received during the period by the Regional Diagnostic Laboratory of the Federal University of Pelotas, causing 267 deaths in a risk population of 6,605 head. The disease affected young and adult cattle mainly during summer. Only one farmer reported that sheep and horses were also affected. Clinically the peracute form was more frequent, but in some outbreaks the acute form with a clinical manifestation period of 6-48 hours was also observed. The source of infection was not established; but the reduced rainfall, associated with low, flat, flooded lands used for agriculture followed by animal grazing after harvest was probably related to the disease occurrence. Annual vaccination is an efficient way to prevent the disease.

Isolamento de Arcanobacterium pyogenes de granuloma actinomicóide em bovino

A round hard lesion measuring 12x11x7cm, with a presumptive diagnosis of lechiguana, was observed in the submandibular region of a cow. Bacteriologic and histologic examinations from biopsies from the lesion were not conclusive. The intradermic test for tuberculosis was negative. The immunodiffusion serologic test to detect antibodies against Pasteurella granulomatis was negative. The animal was killed and necropsied. The submandibular lesion consisted in a hard whitish tissue with yellowish granules measuring up to 3mm scattered within it. A fibrous capsule was surrounding the lesion. Histologically, the lesion was characterized by multifocal piogranulomas with rosetes made up of bacterial colonies in their center, surrounded by Splendore-Hoeppli reaction and neutrophils at the periphery. Epithelioids cells, and fibrous tissue infiltrated by lymphocytes were observed around those lesions. Arcanobacterium pyogenes in pure culture was isolated from samples obtained at necropsy. It is concluded that A. pyogenes could be involved in actinomycotic-like lesion with clinical and pathological aspects similar to lechiguana, tuberculosis and actinobacilosis.

Enfermidades diagnosticadas em bezerros na região sul do Rio Grande do Sul

The aim of this study was to report the frequency of diseases affecting cattle under one year of age in the area of influence of the Regional Diagnostic Laboratory (LRD) of the Veterinary School of the Federal University of Pelotas (UFPel), establishing the main epidemiological factors associated with the occurrence of these diseases. The necropsy protocols and protocols of mailed in tissues from cattle under one year of age, submitted during 2000-2011 to LRD/UFPel for diagnosis, were reviewed. In 35.6% of the cases, the calves were of dairy breeds, 33.9% were beef calves, 18.3% were of mixed breed, and in 12.1% of the cases the breed was not informed. The organ systems most affected were the central nervous system (22.7%), digestive tract (18.6%) and respiratory system (16.8%). The diagnoses were divided by age groups: 88 calves were 1-90 days of age, 42 were 4-6 months, 32 were 7-9 months, and 44 cattle were 10-12 months of age. The disease most often diagnosed in 1 to 90-day-old calves were pneumonia, malformations and encephalitis/meningoencephalitis, with 19.3%, 15.9% and 11.3% of cases respectively. In 4 to 6-month-old calves, pneumonia occurred in 16.5% of cases, and blackleg and diarrhea accounted for 7.1% of diagnoses each. In 7 to 9-month-old calves the most frequent diseases were pneumonia and tetanus with 9.3% of cases, and babesiosis and gastrointestinal parasitosis with 6.2% each. In 10 to 12-month-old calves, infection by BoHV-5 represented 13.6% of cases, and pneumonia, rabies and parasitosis was observed in 9% of cases each. Based on the results of this study it can be concluded that infectious diseases related to the respiratory system were important causes of mortality in calves of all ages until 12 months in the area of influence of LRD and their occurrence may be influenced by environmental factors and by management. Encephalitis/meningoencephalitis were also important as cause of mortality in 3-month-old calves.

Study of bacteria isolated from the foot pad of Spheniscus magellanicus with and without bumblefoot

The bumblefoot or pododermatitis is among the diseases with the highest morbidity in Magellanic penguins, sometimes evolving to septicemia and death. Therefore, this study aimed to relate the main species involved in the disorder, as well as the in vitro susceptibility profile of the microorganisms against routine antimicrobial usage in Veterinary Medicine. During two years in vivo material was harvested from 200 footpads (n=100 animals) for microbiological analysis and in vitro susceptibility tests against the Antibiotic enrofloxacin, streptomycin, penicillin and cephalosporin. Bacteria have been identified both as part of permanent and transient microbiota, also being associated to 100% of the pododermatitis cases. The most prevalent genus were Staphylococcus and Corynebacterium. The antibiograms of all the isolated bacteria resulted in greater susceptibility of the strains facing cephalosporin, followed by enrofloxacin, streptomycin and penicillin.

PROPOLIS: A NATURAL PRODUCT AS AN ALTERNATIVE FOR DISINFECTION OF EMBRYONATED EGGS FOR INCUBATION

During the cooling process of embryonated eggs, there is a natural air flux from the surface to the inner part of the eggs, carrying contaminants such as bacteria and fungi through the shells pores, infecting embryos and resulting in the inability to hatch or poor chick quality. Formaldehyde, a toxic product, is still the most used disinfectant for embryonated eggs in the aviculture industry. In order to evaluate the antimicrobial activity of the green propolis ethanolic extract as an alternative to formaldehyde, 140 hatching eggs from laying hens were collected and submitted to disinfection with five different treatments: T1 - without disinfection; T2 - formaldehyde fumigated eggs; T3, T4 and T5 disinfection by immersion in propolis solution in the concentrations of 2,400 µg, 240 µg and 24 µg, respectively. The contamination levels by total mesophiles and fungi of the egg shells (Aspergillus sp. and other moulds) after disinfection with propolis were lower than when compared to the control without disinfection. In comparison with formaldehyde, the 240 µg and 24 µg propolis concentrations did not differ regarding antibacterial activity, but for antifungal activity the 2,400 µg and 240 µg concentrations were more efficient. The 2,400 µg and 240 µg propolis treatments presented a hatching rate of 94.1%, compared to only 84.6% for the formaldehyde treatment. The green propolis ethanolic extract presented antibacterial and antifungal activities in embryonated eggs showing that it can be a new natural disinfectant product substituting formaldehyde.

Estudos complementares da infecção por Mannheimia granulomatis (lechiguana) em bovinos

Several experiments were performed to demonstrate the role of Dermatobia hominis in the etiology of lechiguana: (1) One calf was infected simultaneously with Dermatobia hominis larvae and Mannheimia granulomatis. Biopsies were performed in two larval lesions. An eosinophilic lymphangitis with connective tissue proliferation, similar to those observed in lechiguana, were present in one biopsy. (2) To detect if Dermatobia hominis is a carrier of Mannheimia granulomatis, a bacteriologic study was performed in 72 larvae and the same number of exudate samples from larval lesions. The bacterium was not isolated. (3) In 9 cattle spontaneously infected by Dermatobia hominis, the larval lesions were inoculated with Mannheimia granulomatis. One bovine whose larval lesions were contaminated with bacteria developed a lechiguana 3 months after inoculation. (4) Two fibroproliferative lesions, clinically similar to lechiguana, caused by Dermatobia hominis larvae were studied. Histologically, these lesions were characterized by proliferation of fibrous tissue with focal granulomas. Eosinophilic lymphangitis and calcification of collagenous fibers were not observed in the lesions. As Dermatobia hominis occasionally produces a fibrogranulomatous reaction, it is possible that this can be the initial lesion for lechiguana, if infected by Mannheimia granulomatis. (5 and 6) Two experiments were performed to detect if healthy cattle can carry Mannheimia granulomatis. The bacterium was not isolated from the tonsils of 153 cattle, and the immunodiffusion test to detect antibodies in cattle was not sufficiently sensitive to detect carrier cattle. (7) Seventeen new spontaneous cases of lechiguana are reported. All cases had the same clinical and pathologic characteristics as previously described. Fourteen cases were from southern Rio Grande do Sul, three were from the state of Santa Catarina and one from Parana.

Morte súbita em bovinos no Sul do Rio Grande do Sul: epidemiologia e diagnóstico

A survey of cases with history of sudden death in cattle was conducted in all necropsy protocols of the Regional Diagnostic Laboratory of the Veterinary School of the Federal University of Pelotas (LRD/UFPel) from 2000 to 2014. We considered animals that had died unexpectedly without prior illness or clinical signs 24 hours before death (Category 1), or before they were moved or suffered some type of management and died after falls or trembling (Category 2). We identified 72 cases (3.5%) from those two categories of a total of 2,031 materials of cattle received in LRD/UFPel. The cases occurred in all seasons of the year. In 34 cases (47.2%), affected cattle had more than four years of age, in 23 cases (31.9%) cattle had between two and three years, and in 11 cases (15.3%) they were up to one year of age. In four protocols (5.6%) age was not reported. In 62 cases (86.1%) the cattle were in an extensive grazing system, in seven (9.7%), they were in a semi-intensive grazing system, and in three cases (4.2%), they were maintained in an intensive farming system. Out of the 72 cases observed, 52 (72.2%) were classified in Category 1 and 20 (27.8%) in Category 2. The diseases that caused more often sudden death, were cerebral babesiosis (10/72), organophosphates poisoning (10/72), anthrax (7/72), bacillary hemoglobinuria (5/72), and fulguration (3/72). Out of the 18 cases considered inconclusive, just five full necropsiey were performed, and of the other 15, the material submitted was considered negative for Bacillus anthracis, and the material did not allow investigation for other diseases. The results showed that sudden deaths in southern Rio Grande do Sul are caused by diseases, mostly well-known and endemic to the region, which can be controlled or prevented by vaccination and appropriate management. Organs sent to the lab instead of the full body, limit the possibilities of conclusive diagnosis in cases of sudden death. The large number of negative cases regarding Bacillus anthracis infection was due to anthrax being a frequent suspicion when cattle appear dead without clinical signs, and the result of sending inappropriate material for the right diagnosis.