Juliana Alves Dias

Isolation and characterization of Streptococcus spp. group B in Nile tilapias (Oreochromis niloticus) reared in hapas nets and earth nurseries in the northern region of Parana State, Brazil

The objective of this study was to isolate and characterize Streptococcus spp. in Nile tilapias (Oreochromis niloticus) reared in net-pens and earth nurseries. Eight intensive tilapia-rearing farms were investigated in north Parana, Brazil from April 1st 2001 to April 30th 2002. The fish were reared in a system of hapas nets on four farms and in earth nurseries on other four farms. A total of 370 samples were analyzed of material collected from 120 fish (brain, liver, kidney, skin scrapes, ascites liquid and eye) that were sown on BHI agar (Brain Heart Infusion) supplemented with 1% yeast extract and sheep blood. Streptococcus spp. was isolated in 36 of the samples (18 brain, eight liver, eight kidney and two ascites liquid) from 25 fish. Streptococci were isolated in both systems, almost in the same proportion. First the streptococci were characterized by the catalase and esculin test, growth in methylene blue and sodium chloride at 6.5%. They were classified in groups by the Slidex Strepto-Kit (BioMerieux, France). The phenotypic characteristics were determined by the Api 20 Strep microtest system (BioMerieux, France). The 36 Streptococcus spp. samples did not present hemolysis and were classified as Lancefield group B. Further 16 samples were identified as Streptococcus agalactiae and 20 were not identified by the Api 20 Strep, but presented the same biochemical profile described for the reference strain of Streptococcus difficile (ND-2-22).

Situação epidemiológica da brucelose bovina no Estado do Paraná

A study to characterize the epidemiological status of brucellosis in the State of Goias was carried out. The State was divided in three regions. Three hundred herds were randomly sampled in each region and a pre-established number of animals was sampled in each of these herds. A total of 10,744 serum samples from 900 herds were collected. In each herd, it was applied an epidemiological questionnaire focused on herd traits as well as husbandry and sanitary practices that could be associated with the risk of infection. The serum samples were screened for antibodies against Brucella spp. by the Rose-Bengal Test (RBT), and all positive sera were re-tested by the 2-Mercaptoethanol test (2-ME). The herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. For region 1, the herd prevalence was 7.7% [4.7-10.7%] and the animal prevalence was 1.4% [0.99-1.7%]. For region 2, the herd prevalence was 19.5% [15.0-24.0%] and the animal prevalence was 2.6% [2.0-3.1%]. For region 3, the herd prevalence was 21.4% [16.8-26.1%] and the animal prevalence was 4.3% [3.7-5.0%]. For the whole state, the herd prevalence was 17.5% [14.9-20.2%] and the animal prevalence was 3.0% [2.7-3.3%]. The multivariate analysis identified the following risk factors (odds ratio, OR) associated with positive herds: purchase of breeding stock from cattle traders (OR = 2.06 [1.12-3.52]), occurrence of abortions over the last 12 months (OR = 5.83 [3.86-8.8]), and vaccination against brucellosis (OR = 2.07 [1.38-3.09]). Both the abortions and the vaccination are, in this case, a consequence of the herd being infected with brucellosis.A study to characterize the epidemiological situation of bovine brucellosis in the State of Parana was carried out. In this study, the State was divided into seven regions. Three hundred herds were randomly sampled in each region and a pre-established number of animals were sampled in each of these herds. A total of 1,4857 serum samples from 2,098 herds were collected. In each herd, it was applied an epidemiological questionnaire regarding herd features and also husbandry and sanitary practices that could be associated with risk of infection. The serum samples were screened for antibodies against Brucella spp. by the Rose-Bengal test (RBT), and all RBT-positive sera were re-tested by the 2mercaptoethanol test (2-ME). A herd was considered positive if at least one animal was positive on both RBT and 2-ME tests. The prevalences of infected herds and infected animals in Parana State were 4.0% [3.2–4.8%] and 1.7% [1.1–2.4%], respectively. In the regions, the prevalences of infected herds and

Fatores de risco associados à infecção pelo herpesvírus bovino 1 em rebanhos bovinos da região Oeste do Estado do Paraná

The aim of this study was to determine the prevalence of positive herds and to identify the risk factors for BoHV-1 infection in breeding cattle herds in the Western region of Parana State. The statistic delineation, the serum samples and information regarding the selected farms, were the same employed in the study of bovine brucellosis for Parana State in the context of National Program for Control and Eradication of Brucellosis and Tuberculosis. The sampling was performed in two stages. Blood samples were collected from 1930 females aged >24 months from 295 non vaccinated herds. Serum samples were tested for antibodies against BoHV-1 using an indirect ELISA. The epidemiological questionnaire was applied on all the selected farms and aimed to obtain epidemiological data. Hundred ninety of the 295 herds were positive for BoHV-1, presenting prevalence of positive herds of 64.41% [58.65-69.87%]. The number (>23) of females aged 24 months (OR=2.22; IC: 1.09-4.51), purchased cattle (OR=2.68; IC: 1.48-4.82), use of common grass (OR=5.93; IC: 1.31-26.82), history of abortion in the last 12 months (OR=2.37; IC: 1.09-5.16) and presence of wildlife animals (OR=8.86; IC: 1.11-70.73) were identified as risk factors for BoHV-1 infection in the multivariate logistic regression. These results indicate that BoHV-1 infection is widespread in the studied region and that factors related to the herd characteristic and management are associated with the infection.

Etiologia das infecções intramamárias em vacas primíparas ao longo dos primeiros quatro meses de lactação

From 88 primiparous cows, belonging to four dairy herds, during 120 days after parturition, one thousand and eighty five milk samples collected, showed 457 (23.02%) positive microbiological results. Coagulase negative staphylococci (CNS) were isolated in 316 (69.14%) samples, Corynebacterium bovis in 56 (12.25%), streptococci in 41 (8.97%) and coagulase positive staphylococci (CPS) in 38 (8.31%). Clinical mastitis was detected in 9 (10.23%) cows. In the first day after parturition, 57 (64.77%) animals and 114 (32.66%) quarters were bacteriologically positive. Until the 14th day there was a remarkable decrease in the number of infections in cows and in quarters, numbers which tended to stabilize later. CNS were isolated through all the experiment while the streptococci tended to disappear in the first few weeks. The infections by C. bovis steadily increased after parturition. Of CNS, S. hyicus and S. intermedius were predominant, and in the streptococci the C and D groups. The average somatic cell count (SCC) was 508.914/m in the infected ones and in the negative quarters It was 73.942/m.

Prevalência de anticorpos anti-Chlamydophila spp. em propriedades rurais com histórico de aborto bovino no estado do Paraná

Chlamydophila abortus is a recognized cause of bovine epizootic abortion. Abortion, premature birth and weak lamb/calf, stillbirth and repeat breeding in irregular intervals are the most frequent disease manifestations. The complement fixation test is the recommended by the World Organization of Animal Health (OIE) for Chlamydophila spp. serologic diagnosis. The aim of this study was estimate the prevalence of antibodies against Chlamydophila spp. in cattle herds with abortion, selected inside the sampling design of National Program of Control and Erradication of Brucellosis in Parana state. Serum samples of 3,102 cows (age > 24 months) from 373 herds were analyzed by complement fixation test. Totally, 44 (1.42%) animal were positive with titers > 32. The seroprevalence of Chlamydophila spp. in the herds was 8.82% (6.15%-12.17%). Four variables were associated with seroprevalence for Chlamydophila spp. in the final model of logistic regression: confined or semi-confined breeding (OR=3.339, P=0.004), farms with less than 35 cows (OR=3.339, P=0.017), abortion in the pasture (OR=2.372, P=0.037) and pasture rent (OR=3.398, P=0.006) were risk factors for Chlamydophila spp. This bacterium infected a small number of cattle from herds with abortion in Parana state. Chlamydophila spp impact as abortion cause is reduced in this state.