Fungal flora on cutaneous and mucosal surfaces of cats infected with feline immunodeficiency virus or feline leukemia virus

OBJECTIVE: To compare cutaneous and mucosal mycoflora in cats infected with FIV or FeLV with that in noninfected cats. ANIMALS: 85 client-owned cats; 24 seropositive for FIV, 10 seropositive for FeLV, 1 seropositive for both viruses, and 50 seronegative for both viruses. PROCEDURE: Cutaneous specimens were obtained from the coat and external acoustic meatus (ear canal) and mucosal specimens from the oropharynx and rectum. Fungi were isolated from specimens, using Sabouraud dextrose agar incubated at 27 or 37 C for cutaneous and mucosal specimens, respectively. RESULTS: Fungal colonies were cultured from at least 1 specimen from 83 of 85 (97.6%) cats. The most common fungal isolates were Aspergillus spp (cultured from 59.3% of all specimens), Penicillium spp (50.0%), Cladosporium spp (44.2%), Scopulariopsis spp (41.8%), and lipophilic yeasts of the genus Malassezia (31.4%). A greater diversity of fungal genera was isolated from retrovirus-infected cats, and Malassezia spp were more commonly recovered from these cats, compared with noninfected cats. Candida albicans, Cryptococcus neoformans, and dermatophytes (eg, Microsporum canis) were rarely isolated from any cat. Significant differences in frequency of isolation of C. neoformans and dermatophytes were not found between infected and noninfected cats. CONCLUSIONS AND CLINICAL RELEVANCE: Cats infected with FIV or FeLV may have a greater diversity of cutaneous and mucosal mycoflora than noninfected cats. However, infected cats may be no more likely than noninfected cats to expose humans to zoonotic fungi such as C. albicans, C. neoformans, and M. canis.     

Evaluation of the association between initial proteinuria and morbidity rate or death in dogs with naturally occurring chronic renal failure

OBJECTIVE: To determine whether urine protein-to-creatinine ratio (UP:C) > or = 1.0 at initial diagnosis of chronic renal failure (CRF) is associated with greater risk of development of uremic crises, death, and progression of renal failure in dogs. DESIGN: Prospective cohort study. ANIMALS: 45 dogs with CRF PROCEDURE: Dogs were prospectively assigned to 2 groups on the basis of initial UP:C < 1.0 or 2 > or = 1.0. The association between magnitude of proteinuria and development of uremic crises and death was determined before and after dogs with initial UP:C > or =1.0 were assigned to 3 subgroups and compared with dogs with initial UP:C < 1.0. Changes in reciprocal serum creatinine concentration were used to estimate decrease in renal function. RESULTS: Initially, dogs had similar clinical characteristics with the exception of systolic blood pressure and UP:C. Relative risks of development of uremic crises and death were approximately 3 times higher in dogs with UP:C > or =1.0, compared with dogs with UP:C < 1.0. Relative risk of adverse outcome was approximately 1.5 times higher for every 1-unit increment in UP:C. The decrease in renal function was of greater magnitude in dogs with UP:C > or =1.0, compared with dogs with UP:C < 1.0. CONCLUSIONS AND CLINICAL RELEVANCE: Initial UP:C > or =1.0 in dogs with CRF was associated with greater risk of development of uremic crises and death, compared with dogs with UP:C < 1.0. Initial determinations of UP:C in dogs with naturally occurring CRF may be of value in refining prognoses.     

Acute cortisol responses of calves to scoop dehorning using local anaesthesia and/or cautery of the wound

Objective To measure plasma cortisol responses in calves dehorned using a scoop after administration of local anaesthesia and/or cautery of the wounds.
Design A physiological study with controls.
Procedure There were six treatments: control handling with and without local anaesthesia, dehorning, dehorning after local anaesthesia, dehorning followed by wound cautery, and dehorning after local anaesthesia followed by wound cautery. Blood samples were taken before and after dehorning.
Results Dehorning caused an increase in plasma cortisol concentrations, which decreased a little to plateau values and then declined to pretreatment values 3 to 4 h after dehorning. The peak was smaller after local anaesthesia was administered but when its effects wore off, cortisol concentrations increased and thereafter were similar to those in the dehorned animals. The combination of local anaesthesia and cautery resulted in a plasma cortisol response similar to those in control calves with or without local anaesthesia.
Conclusions If plasma cortisol concentrations reflect the distress being experienced by the calves, then local anaesthesia reduces the acute distress for about 3 h after dehorning but not during the subsequent 3 to 4 h. Combining local anaesthetic and cautery prevented the significant increase in plasma cortisol following dehorning and may eliminate the acute distress caused by scoop dehorning.     

Pharmacokinetics of subcutaneously administered doramectin in alpacas

The objective of this research was to evaluate comparative pharmacokinetics of doramectin in alpacas, after subcutaneous administration of 0.2 mg/kg dose. Six healthy adult alpacas, mean age of 5 years ± 1, (three female and three gelded males) of mean bodyweight of 62 kg ± 16 kg with an average body condition scored 2.8 ± 1 out of five, were used in this study. Serial blood samples were collected from the jugular vein before the administration until day 21 afterwards to establish the pharmacokinetics of doramectin after its subcutaneous administration at 0.2 mg/kg dose. The blood samples were analysed using high-performance liquid chromatography (HPLC), fluorescence detection method with precolumn derivatisation, validated for alpacas. The pharmacokinetic parameters were calculated using a noncompartmental model, and results showed Cmax (6.05 ± 5.34 ng/ml), Tmax (3.83 ± 2.48 days), AUC (62.12 ± 18.86 ng/ml × d), terminal half-life (6.2 ± 4.9 days) and MRT (11.56 ± 4.43 days). The results of this study showed that the Cmax and AUC were much lower than in cattle and sheep at the same dosage. Tmax remained similar to cattle and sheep. This study presents valuable information about pharmacokinetics of doramectin in alpacas, which can be utilised in its future efficacy studies.     

Mitochondrial DNA variation of the dog hookworm Ancylostoma caninum in Brazilian populations

The mitochondrial cytochrome oxidase I gene was partially sequenced for 164 Ancylostoma caninum individuals, originating from five different localities in Brazil, with the aim of describing the genetic diversity and genetic structure of Brazilian hookworm populations. Allelic and nucleotide diversity were moderate (overall h=0.88 and pi=0.016) and were similar among cities. There was moderate genetic differentiation among the populations sampled (approximately Phi(ST)=0.12) and a weak but nonsignificant correlation between geographical and genetic distance. This genetic structure was similar to that observed among populations of the human hookworm, Necator americanus, but distinct from that typically found in trichostrongylid nematode parasites of livestock. Thus, a pattern of different genetic structures among different groups of nematodes is emerging. We also observed a few individuals that had a highly divergent mtDNA sequence (almost 7% sequence divergence from the other sequences). These results in combination with data from other studies suggest that A. caninum populations worldwide consist of a mix of previously differentiated populations, or perhaps even cryptic species. This study contributes to the knowledge of genetic structure and diversity of hookworms, which in turn will be useful in developing methods for their control.     

Major ascaroside pheromone component asc-C5 influences reproductive plasticity among isolates of the invasive species pinewood nematode

Pheromones are communication chemicals and regulatory signals used by animals and represent unique tools for organisms to mediate behaviors and make “decisions” to maximize their fitness. Phenotypic plasticity refers to the innate capacity of a species to tolerate a greater breadth of environmental conditions across which it adapts to improve its survival, reproduction, and fitness. The pinewood nematode, Bursaphelenchus xylophilus, an invasive nematode species, was accidentally introduced from North America into Japan, China, and Europe; however, few studies have investigated its pheromones and phenotypic plasticity as a natural model. Here, we demonstrated a novel phenomenon, in which nematodes under the condition of pheromone presence triggered increased reproduction in invasive strains (JP1, JP2, CN1, CN2, EU1, and EU2), while it simultaneously decreased reproduction in native strains (US1 and US2). The bidirectional effect on fecundity, mediated by presence/absence of pheromones, is henceforth termed pheromone-regulative reproductive plasticity (PRRP). We further found that synthetic ascaroside asc-C5 (ascr#9), the major pheromone component, plays a leading role in PRRP and identified 2 candidate receptor genes, Bxydaf-38 and Bxysrd-10, involved in perceiving asc-C5. These results suggest that plasticity of reproductive responses to pheromones in pinewood nematode may increase its fitness in novel environments following introduction. This opens up a new perspective for invasion biology and presents a novel strategy of invasion, suggesting that pheromones, in addition to their traditional roles in chemical signaling, can influence the reproductive phenotype among native and invasive isolates. In addition, this novel mechanism could broadly explain, through comparative studies of native and invasive populations of animals, a potential underlying factor behind of the success of other biological invasions.     

Effects of feeding wet corn distillers grains with solubles with or without monensin and tylosin on the prevalence and antimicrobial susceptibilities of fecal foodborne pathogenic and commensal bacteria in feedlot cattle

Distillers grains, a coproduct of ethanol production from cereal grains, are composed principally of the bran, protein, and germ fractions and are commonly supplemented in ruminant diets. The objective of this study was to assess the effect of feeding wet distillers grains with solubles (WDGS) and monensin and tylosin on the prevalence and antimicrobial susceptibilities of fecal foodborne and commensal bacteria in feedlot cattle. Cattle were fed 0 or 25% WDGS in steam-flaked corn-based diets with the addition of no antimicrobials, monensin, or monensin and tylosin. Fecal samples were collected from each animal (n = 370) on d 122 and 136 of the 150-d finishing period and cultured for Escherichia coli O157. Fecal samples were also pooled by pen (n = 54) and cultured for E. coli O157, Salmonella, commensal E. coli, and Enterococcus species. Antimicrobial resistance was assessed by determining antimicrobial susceptibilities of pen bacterial isolates and quantifying antimicrobial resistance genes in fecal samples by real-time PCR. Individual animal prevalence of E. coli O157 in feces collected from cattle fed WDGS was greater (P < 0.001) compared with cattle not fed WDGS on d 122 but not on d 136. There were no treatment effects on the prevalence of E. coli O157 or Salmonella spp. in pooled fecal samples. Antimicrobial susceptibility results showed Enterococcus isolates from cattle fed monensin or monensin and tylosin had greater levels of resistance toward macrolides (P = 0.01). There was no effect of diet or antimicrobials on concentrations of 2 antimicrobial resistance genes, ermB or tetM, in fecal samples. Results from this study indicate that WDGS may have an effect on the prevalence of E. coli O157 and the concentration of selected antimicrobial resistance genes, but does not appear to affect antimicrobial susceptibility patterns in Enterococcus and generic E. coli isolates.