Prevalence of ectoparasites in a population of feral cats from north central Florida during the summer

Ectoparasites are a common and important cause of skin disorders in cats. Ectoparasites are capable of disease transmission and can cause life-threatening anemia in young or debilitated animals. The objective of this study was to determine the potential feline ectoparasites in domestic cats by using a cohort of feral cats from north central Florida that have not received veterinary care and have no known exposure to insecticide application. A total of 200 feral cats were randomly selected for this study. Four monthly sessions were scheduled for feral cat ectoparasite examination and sample collection. Five minutes flea combing revealed that 185/200 (92.5%) of the cats were infested with fleas. The cat flea, Ctenocephalides felis was the most common flea infesting 92.5% feral cats (mean = 13.6; standard deviation +/- 16.4 fleas per cat). Pulex simulans was identified on 9/200 (4.5%) (mean = 1 +/- 0.50 fleas per cat). Echidnophaga gallinacea was found on 11/200 (5.5%) of cats (mean = 14.8 +/- 9.63 fleas per cat). There was a significant difference (P = 0.0005) in the average number of C. felis counted per cat between months. Mean counts in June (18.3 +/- 2.4) and July (16.6 +/- 2.1) were significantly (P < 0.01) higher than in August (8.4 +/- 2.5) and September (7.7 +/- 2.0). Only 15/200 cats had skin disease. Flea infestation may potentially be the underlying cause in 10/15. Otoscopic examination of both ears revealed mite movement and black ceruminous exudate typically indicative of the presence of Otodectes cynotis in 45/200 (22.5%) cats. Examination of a swab specimen from both ear canals of all cats revealed O. cynotis in 74/200 (37%) cats. Of 74 cats positive on ear swab, 8 (10.8%) showed a normal ear canal appearance (no or mild ceruminous exudate) in both ears upon otoscopic examination. A total of nine ticks were recovered from five cats. The number and species of ticks recovered were: one adult female Rhipicephalus sanguineus; one adult female Amblyomma americanum; one adult male A. americanum; five adult female Dermacentor variabilis; and one adult female Ixodes scapularis. All superficial skin scrapes were negative. Hair clippings from the abdomen of all cats revealed 2/200 (1%) of the cats were infested with Felicola subrostratus.     

The isolation, propagation and characterization of tissue-cultured equine rotaviruses

From 105 field cases of diarrhea in neonatal or young foals, rotavirus was detected by electron microscopy (EM) and/or by enzyme-linked immunosorbent assay (ELISA) in the feces of 65 foals on 16 different premises. ELISA was performed with Rotazyme test kits developed by Abbot and Company for the detection of rotaviruses. Twenty-four field isolates from the feces of diarrheic foals with equine rotavirus infection as ascertained by EM were placed in MA-104 cell cultures after pretreatment of the viral suspension with 10 micrograms ml-1 of trypsin and incorporation of 0.5 micrograms ml-1 or 1 microgram ml-1 of trypsin in Earle's minimal essential medium (MEM), 2% lactalbumen hydrolysate, and antibiotics. The isolates that replicated in cell culture produced varying degrees of cytopathic effect. After the 24 isolates had been transferred 5 or 7 times in cell culture, viral particles were observed in 17 by EM, and 22 had positive ELISA tests as determined by visual color chart and spectrophotometric readings. Concentrated tissue-cultured viral antigen of 9 isolates fixed complement using Nebraska calf diarrhea rotavirus calf antiserum while four isolates gave negative results. The same 13 tissue-cultured viral suspensions failed to fix complement using reovirus antiserum. The 9th passages of two isolates (EID1 and EID2) yielded titers of 10(4.45) ml-1 TCID50 and of 10(4.95) ml-1 TCID50, respectively, as measured by cytopathic effect. After 13 tissue-cultured passages, 2 other isolates, EID3 and EID4, each had titers of 10(6.2) ml-1 TCID50 and of 10(5.95) ml-1 TCID, respectively. Cytoplasmic or intranuclear inclusions were not seen in any cells of the MA-104 infected cell cultures. Small, but distinct, plaques in MA-104 cell cultures were produced by the EID1 isolate. Polyacrylamide gel electrophoresis tests of EID1 and EID2 isolates at the 9th cell passage and EID3 and EID4 isolates at the 13th cell passage each showed that the RNA genome had 11 segments with a migrating pattern that was identical for each isolate and characteristic of rotaviruses. These 4 equine tissue-cultured isolates when tested by ELISA, utilizing a monoclonal antibody serum pool that cross-reacted with many rotavirus isolates, each gave positive values comparable to rotavirus antigen controls.     

Lectin Histochemistry as a Tool to Identify Apoptotic Cells in the Seminiferous Epithelium of Syrian Hamster (Mesocricetus auratus) Subjected to Short Photoperiod

Lectins have been widely used to study the pattern of cellular glycoconjugates in numerous species. In the process of cellular apoptosis, it has been observed that changes occur in the membrane sugar sequences of these apoptotic cells. The aim of our work was to identify which lectins, out of an extensive battery of the same (PNA, SBA, HPA, LTA, Con‐A, UEA‐I, WGA, DBA, MAA, GNA, AAA, SNA), show affinity for germinal cells in apoptosis, at what stage of cell death they do so and in which germinal cell types they can be detected. For this, we studied testis sections during testicular regression in Syrian hamster (Mesocricetus auratus) subjected to short photoperiod. Several lectins showed an affinity for the glycoconjugate residues of germ cells in apoptosis: Gal β1,3‐GalNAcα1, α‐d ‐mannose, N‐acetylgalactosamine and l ‐fucose. Furthermore, lectin specificity was observed for some specific germinal cells and in certain stages of apoptosis. It was also observed that one of these lectins (PNA) showed affinity for Sertoli cells undergoing apoptosis. Therefore, we conclude that the use of lectin histochemistry could be a very useful tool for studying apoptosis in the seminiferous epithelium because of the specificity shown towards germinal cells in pathological or experimentally induced epithelial depletion models.     

Field studies on the biological control of nematode parasites of sheep in the tropics, using the microfungus Duddingtonia flagrans

Long-term field studies were conducted on two government managed small ruminant research farms, located in different geo-climatic regions and approximately 300 km separate from each other, on Peninsula Malaysia. The Infoternak trial (48 weeks) and the Chalok trial (43 weeks) each compared nematode parasite control in separately managed groups of young sheep, either short-term rotationally grazed around a suite of 10 paddocks in addition to receiving a daily supplement of Duddingtonia flagrans spores (Fungus Group); or similar groups of sheep being rotationally grazed alone (Control Group). The prevailing weather conditions at Infoternak farm were of below average rainfall conditions for the most of the trial. As a consequence, only very low worm infections (almost exclusively Haemonchus contortus) were acquired by the 17 sets of tracer lambs that grazed sequentially with the experimental lambs. However on all except 2 occasions in the early part of the trial, the mean tracer worm burdens were significantly lower (P < 0.05) and the experimental lambs grew significantly better (P = 0.054) in the Fungus Group. Rainfall at Chalok farm during the course of the trial was also below average. As a consequence infectivity of pastures was assumed to be relatively low based on faecal egg counts (epg) of the experimental sheep, which following an anthelmintic treatment prior to allocation, remained very low in both treatment groups. Faecal egg counts of undosed replacement lambs in the latter half of the Chalok study, showed a progressive increase in the Control Group to levels exceeding 3000 epg, whereas the Fungus Group remained static at approximately 500 epg. These results show that the deployment of the nematophagous fungus, D. flagrans, can improve the level of parasite control of sheep in the tropics above that which can be achieved by the short-term rotational grazing strategy alone.     

Isolation and molecular characterisation of Neospora caninum in cattle in New Zealand

AIM: To isolate Neospora caninum from the brains of naturally infected cattle and use molecular techniques to characterise the isolates.

METHODS: Neospora caninum tachyzoites were isolated in Vero cell culture from the brains of a cow and two calves. The isolates were characterised using polymerase chain reaction (PCR) methods, DNA sequencing, an immunofluorescent anti-body test (IFAT), transmission electron microscopy (TEM), and immunohistochemistry (IHC). The brains of the three cattle were subjected to histopathological examination. A pathogenicity study was conducted in 120 BALB/c mice.

RESULTS: Neospora caninum tachyzoites were isolated from all three cases and first observed in vitro between 14 and 17 days post-inoculation. Parasites were sub-cultured and maintained in Vero cell culture for more than 6 months. PCR products were generated for all three isolates, using two different primers. Sequencing of the PCR products and a subsequent BLAST search identified the isolates as N. caninum. In addition, the isolates tested positive using IFAT and IHC, and ultrastructure revealed by TEM was characteristic of N. caninum. Histopathological examination revealed lesions characteristic of N. caninum in 1/3 brains. In the pathogenicity study using BALB/c mice, the mortality rate was 3–7%.

CONCLUSION: This was the first successful isolation of N. caninum in New Zealand confirmed using molecular characterisation tests.     

Phenotypic and genotypic antimicrobial resistance patterns of Escherichia coli isolated from dairy cows with mastitis

Pulsed field gel electrophoresis (PFGE) patterns, susceptibility to 26 antimicrobial agents used in veterinary and human medicine, and prevalence of antimicrobial resistance genes of Escherichia coli isolated from cows with mastitis were evaluated. Among 135 E. coli isolates, PFGE analysis revealed 85 different genetic patterns. All E. coli were resistant to two or more antimicrobials in different combinations. Most E. coli were resistant to antimicrobials used in veterinary medicine including ampicillin (98.4%, >or=32 microg/ml) and many E. coli were resistant to streptomycin (40.3%, >or=64 microg/ml), sulfisoxazole (34.1%, >or=512 microg/ml), and tetracycline (24.8%, >or=16 microg/ml). Most E. coli were resistant to antimicrobials used in human medicine including aztreonam (97.7%, >or=32 microg/ml) and cefaclor (89.9%, >or=32 microg/ml). Some E. coli were resistant to nitrofurantoin (38%, >or=128 microg/ml), cefuroxime (22.5%, >or=32 microg/ml), fosfomycin (17.8%, >or=256 microg/ml). All E. coli were susceptible to ciprofloxacin and cinoxacin. Almost 97% (123 of 127) of ampicillin-resistant isolates carried ampC. Eleven of 52 (21.2%) streptomycin-resistant isolates carried strA, strB and aadA together and 29 streptomycin-resistant isolates (55.8%) carried aadA alone. Among 44 sulfisoxazole-resistant E. coli, 1 isolate (2.3%) carried both sulI and sulII, 12 (27.3%) carried sulI and 10 (22.7%) isolates carried sulII. Among 32 tetracycline-resistant isolates, 14 (43.8%) carried both tetA and tetC and 14 (43.8%) carried tetC. Results of this study demonstrated that E. coli from cows with mastitis were genotypically different, multidrug resistant and carried multiple resistance genes. These bacteria can be a reservoir for antimicrobial resistance genes and can play a role in the dissemination of antimicrobial resistance genes to other pathogenic and commensal bacteria in the dairy farm environment.     

Colour Doppler Ultrasonography as a Tool to Assess Luteal Function in Santa Inês Ewes

The aim of this study was to evaluate luteal dynamics in the Santa Inês ewes using colour Doppler (CD) ultrasonography. Oestrus was synchronized in nulliparous females (n = 18), and subsequently, they were only teased (n = 6) or teased and mated (n = 12). Blood samples were collected daily for plasma progesterone (P₄) concentrations. Ultrasonographic images of corpora lutea (CL) in CD mode were obtained for further analysis in its largest diameter. The CD mode allowed an early sequential monitoring of CL that was visualized by the first time 0.77 ± 0.62 days after ovulation, with luteal area 29.68 ± 13.21 mm². During the luteogenesis, a progressive increase was observed, followed by a plateau of luteal area, vascularization area and plasma concentrations of P₄ reaching maximum values in D11 (124.0 ± 38.0 mm², 52.78 ± 24.08 mm² and 11.23 ± 4.89 ng/ml, respectively). In the luteolysis, the plasma concentrations of P₄ decreased sharply, whereas luteal and vascularization area gradually. The vascularization area was positively correlated with plasma concentrations of P₄ during the luteogenesis (r = 0.22) and luteolysis (r = 0.48). The luteal dynamics of Santa Inês ewes showed patterns similar to those observed in other sheep breeds studied. The CD ultrasonography has the potential to be used as a tool to assess luteal function in sheep.     

The Morphogenesis of Bands and Zonal Winds in the Atmospheres on the Giant Outer Planets

The atmospheres of Jupiter, Saturn, Uranus, and Neptune were modeled as shallow layers of turbulent fluid overlying a smooth, spherical interior. With only the observed values of radius, rotation rate, average wind velocity, and mean layer thickness as model parameters, bands and jets spontaneously emerged from random initial conditions. The number, width, and amplitude of the jets, as well as the dominance of anticyclonic vortices, are in good agreement with observations for all four planets.