Use of ivermectin in treatment of Aelurostrongylus abstrusus and Toxocara cati infection in a cat

Ivermectin, administered at a rate of 200 micrograms/kg of body weight, SC, successfully removed Toxocara cati infection from a young cat. A second treatment at a higher rate (400 micrograms/kg) was necessary to eliminate infection with the lungworm Aelurostrongylus abstrusus. The drug apparently was tolerated well, and it appears to have several advantages over previously reported treatments for lungworm infections in cats.     

Aelurostrongylus abstrusus (cat lungworm) infection in five cats from Italy

Infection by the cat lungworm Aelurostrongylus abstrusus is considered uncommon. Here, the authors report the clinical, diagnostic and therapeutic features of five infections recently observed in Italy. All cats were under 12 months of age. All except one cat had symptomatic infections, with cough, dyspnea, and weight loss with radiographic signs of broncopneumonia. All cats were eosinophilic. Larvae were present in fresh fecal smears and on flotation exam in all cats. Baermann larval recovery permitted definitive identification and, in one case, larvae per gram of feces (lpg) counts. One dose of ivermectin (400 microg/kg) was not effective in one cat, while one dose of selamectin (6 mg/kg) was effective in one of three cases and fenbendazole at 50 mg/kg given daily for 15 days was effective in four of four cases.     

Changes in the ultrastructure of feline pulmonary arteries following infection with the lungworm Aelurostrongylus abstrusus

A study was made of the ultrastructural changes which occur in feline pulmonary arteries as a consequence of experimental infection with the lungworm Aelurostrongylus abstrusus.Pulmonary tissue was studied at intervals from 10 days to 24 weeks post infection. There was progressive disruption of the vascular endothelium resulting in vacuolation and later proliferation of the endothelial cells. Eosinophils were observed migrating through the artery walls as early as 10 days post infection, resulting in disruption of the internal elastic laminae and contributing to the disruption of the endothelium. Hypertrophy and hyperplasia of the smooth muscle cells of the media were evident and this, together with intimai proliferation, resulted in complete occlusion of the lumen of many of the vessels by 24 weeks post infection. Immunofluorescence failed to reveal any evidence of immune complex deposition in pulmonary vasculature or parenchyma at any stage of the infestation. The possible role of endogenous vasoactive compounds in the genesis of the lesion is discussed.     

Evaluation of immunogenicity and protective efficacy of adjuvanted Salmonella Typhimurium ghost vaccine against salmonellosis in chickens

Background: Salmonella Typhimurium, a non-host-adapted Gram-negative intracellular pathogen, is capable of infecting a variety of animal hosts and humans.

Objective: This study utilized the prime-booster immunization strategy using Salmonella Typhimurium–LTB (S. Typhimurium–LTB) ghost with the aim of inducing a robust immune response for the prevention of avian salmonellosis. In addition, the effect of Montanide^TM ISA 70VG adjuvant on S. Typhimurium–LTB ghost vaccination was investigated.

Animals and methods: A total of 75 chickens were divided into three groups (n=25) for intramuscular immunization: group A (non-immunized control injected with sterile PBS), group B (immunized with S. Typhimurium–LTB ghost), and group C (immunized with S. Typhimurium–LTB ghost plus Montanide^TM ISA70VG adjuvant).

Results: Compared with group A, the immunized chickens (groups B and C) exhibited increased titers of antigen specific plasma IgG and intestinal secretory IgA antibodies. In addition, group C showed enhanced induction of the humoral immune response compared to group B. The populations of splenic CD3+CD4+ and CD3+CD8+ T-cells increased significantly in both immunized groups. In addition, increased mRNA expression of the Th1 cytokines, IFN-γ, and IL-2 were observed in S. Typhimurium antigen-stimulated peripheral blood mononuclear cells from groups B and C chickens. Chickens from both vaccinated groups showed significant protection against virulent S. Typhimurium oral challenge compared to non-vaccinated chickens and a lower challenge strain count was recovered from the internal organs of group C.

Conclusions: Injection of S. Typhimurium-LTB ghost with or without Montanide^TM ISA70VG adjuvant is capable of inducing protective immunity against the virulent S. Typhimurium infection in chickens.     

Serum proteins in normal cats and cats infected with Aelurostrongylus abstrusus

Serum proteins were evaluated by cellulose acetate electrophoresis in cats prior to and every 2 weeks for 24 weeks after oral infection with third stage larvae of Aelurostrongylus abstrusus. Evaluation of electrophoretograms was standardized by determination of electrophoretic migration ratios. Six fractions of serum proteins were consistently identified: albumin and alpha 1, alpha 2, beta 1, beta 2, and gamma globulin. Relative and absolute concentrations of each serum protein fraction were determined. The only changes found were a decrease in concentration of alpha globulins and an increase in concentration of beta 1 globulins. These changes were mild, however, so that the the concentrations for infected cats were still within 1 SD of the control concentrations. Apparently serum electrophoresis is not a useful diagnostic test for aelurostrongylosis.     

Diagnosis of Aelurostrongylus abstrusus and Dirofilaria immitis infections in cats from a human shelter

During a 6-month period, 108 sexually mature stray cats were euthanatized at a humane shelter in Alabama. Aelurostrongylus abstrusus was identified in 20 of the cats (18.5%) by Baermann fecal examination, necropsy, or histologic examination. The Baermann fecal examination was a more sensitive test for aelurostrongylosis than was necropsy or histologic examination. Thoracic radiography was useful in identifying infected cats, but was a less sensitive and more nonspecific method of detection than was the fecal examination. Changes in CBC and serum protein concentrations were not helpful identifying cats with aelurostrongylosis. Six of 17 (35%) heartworm-free, lungworm-infected cats had antibodies to Dirofilaria immitis, as determined by an ELISA method, but none had circulating D immitis antigen, as determined by an ELISA method. Three (2.8%) cats had D immitis. Two of the heartworm-infected cats had no detectable antemortem radiographic or clinicopathologic evidence of the infection. Results of ELISA were positive for antibodies to adult heartworms in 2 cats and for circulating heartworm antigen in 2 cats. One cat that had only one heartworm had no detectable circulating heartworm antigen.     

Diagnosis and risk factors of Aelurostrongylus abstrusus (Nematoda, Strongylida) infection in cats from Italy

Aelurostrongylus abstrusus (Nematoda, Strongylida) in cats and associated risk factors have been investigated by classical coprology in central (site A) and southern (site B) Italy, i.e. by floatations with sugar and zinc sulphate solutions and a Baermann technique. Overall, 227 individual stool samples (i.e. 162 from site A and 65 from site B) were processed and risk factors were related to infection by binary logistic multiple-regression models. The presence of A. abstrusus was used as the dependent variable and the epidemiological data as independent variables. Twenty-eight (17.3%) and 12 (18.5%) cats were positive for A. abstrusus in sites A and B, respectively, both using the Baermann and flotation with zinc sulphate solution methods. Six and three (from site A and B, respectively) of the infected cats were negative for A. abstrusus when faeces were processed with sugar solution. Stray and free-ranging (P=0.357), young cats (P=0.008) and the presence of respiratory symptoms (P=0.000) were risk factors for A. abstrusus infection. The results suggest that A. abstrusus is spread in Italy. Furthermore, these results possibly include infection in the differential diagnosis of feline respiratory diseases and offer a correct diagnostic approach by using either a Baermann method or flotation with zinc sulphate solution in suspected cases.     

Congenital supravalvular aortic stenosis in a kitten

A three-month-old, male intact Norwegian forest cat without any clinical signs was referred to the cardiology service of the author’s teaching hospital for evaluation of a cardiac murmur. The murmur was systolic with an intensity of 4 out of 6 with the point of maximal intensity at the left heart base. Echocardiography revealed a moderate mitral valve regurgitation and a moderate dynamic left ventricular outflow tract obstruction both resulting from systolic anterior motion of the mitral valve (SAM). Moreover, left ventricular concentric hypertrophy was noted. Oral atenolol therapy was initiated. Recheck examination 3.5 months later revealed unchanged murmur characteristics in the still asymptomatic kitten. Echocardiography showed no SAM, but there was a severe fixed aortic stenosis apparent caused by a discrete supravalvular lesion, 4 mm distal to the valve, with an hourglass morphology. Supravalvular aortic stenosis is a rare congenital anomaly in cats, which has not been reported antemortem yet.     

Simultaneous detection of the feline lungworms Troglostrongylus brevior and Aelurostrongylus abstrusus by a newly developed duplex-PCR

In addition to Aelurostrongylus abstrusus (Strongylida: Angiostrongylidae), referred to as the feline lungworm, Troglostrongylus brevior (Strongylida: Crenosomatidae) has recently been identified as an agent of bronco-pulmonary infestations in cats. These two parasites have a similar biology, share ecological niches, potentially co-infesting cats, but are difficult to be differentiated due to the morphological similarities of their first-stage larvae (L1). This paper describes a molecular tool, based on single-step duplex polymerase chain reaction (duplex-PCR) on the ribosomal internal transcribed spacer 2 region (ITS-2) for the simultaneous detection and differentiation of T. brevior and A. abstrusus. L1 of both species were collected from faecal samples, morphologically identified, and single larval specimens isolated. An aliquot of faeces was used as a test sample for a case of mixed natural infestation. The duplex-PCR was performed using species-specific forward primer sets for the ITS-2 region (i.e., A. abstrusus: 220 bp; T. brevior: 370 bp). The detection limit of the molecular assay was also assessed by serial dilutions of DNA from single larvae of both species (from ～4.0 to 4.0 × 10^?5 μg/μl). The duplex-PCR carried out on individual DNA samples was able to detect as low as 5.2 × 10^?3 μg/μl of DNA for A. abstrusus, 4.9 × 10^?3 μg/μl for T. brevior, and as low as 4.0 × 10^?3 μg/μl for samples containing both species. Species-specific bands of the expected sizes and two bands were simultaneously amplified from the faecal sample containing both species. The phylogenetic analyses of the ITS-2 sequences here examined and those available for other metastrongyloids were concordant in clustering them with those of other Troglostrongylus brevior and A. abstrusus sequences available in GenBank database. This molecular approach proved to be effective and highly sensitive for the simultaneous detection of the two lungworms species and it might be used for molecular epidemiological studies and for monitoring therapeutic protocols.     

Salmonella Typhimurium persistence in a Hunter Valley dairy herd

OBJECTIVE: An epidemiological study was undertaken at a Hunter Valley dairy with persistent Salmonella Typhimurium infection. The aim of the study was to identify cattle currently or previously infected with Salmonella, possible sources of the organism, patterns of spread, and husbandry practices that could be improved. METHODOLOGY: Faecal samples, feed, water and environmental samples were cultured for Salmonella and blood samples were tested for antibodies against Salmonella (Dublin and Typhimurium). A questionnaire was designed to identify possible risk factors associated with Salmonella excretion. RESULTS: S Typhimurium was apparently introduced from an old to a new dairy through manure spread as fertiliser. Salmonella apparently persisted in the effluent pond, and the following year clinical cases occurred after pasture, irrigated with water from the pond, was grazed by dry cows, and adult cattle became clinically ill with salmonellosis. The disease spread to other cows and calves. Poor design of calf pens assisted spread of Salmonella from sick to healthy calves. In addition, there was suspected transmission to the dairy farmer's 9-month-old daughter. Salmonellosis on a farm is a potential zoonotic risk to farm workers and their families. There is also the risk that cull cows may carry Salmonella to the abattoir and subsequently into the human food chain. Methods of waste management, and the design of calf pens, were identified as major risk factors that could be improved to minimise the spread of salmonellosis on this property.     

Qualitative and quantitative risk assessment for human salmonellosis due to multi-resistant Salmonella Typhimurium DT104 from consumption of Danish dry-cured pork sausages

Salmonella Typhimurium DT104 (DT104) is unwanted in products for human consumption due to its antibiotic resistance and ability to cause disease. We intended to set up an improved monitoring and management program to aid in deciding when to use pork contaminated with DT104 for production of sausages without jeopardizing consumer safety. We started by carrying out two assessments of the risk for human health associated with consumption of sausages produced by: (1) Danish pork from average slaughter days; (2) imported pork (IMP) with average prevalence of DT104. The assessments showed that, if Salmonella is present, it is usually in lower numbers (≤50 per 400 cm² surface). Additionally, during processing, the numbers will be reduced by at least 2 log-units. In Danish (DK) pork, DT104 constitutes 0.2–1.0% of the Salmonella isolates reported, while in imported pork (IMP), 18%. We estimated that out of one million, 25 g servings of DK dry-cured sausages, up to two DT104 bacteria could be found in each of 245 servings. Out of one million servings of 25 g IMP dry-cured sausages, up to two DT104 bacteria would occur in each of 19,260 servings.     

甘孜州牦牛沙门氏菌的分离和鉴定

2010年6月,四川省甘孜州炉霍县某乡12户牧民的100多头成年牦牛发生了以呼吸困难和腹泻为主要特征的疾病,根据流行病学情况、临床症状、病理解剖学变化、实验室分离鉴定,结合16SrRNA基因测序和同源性比对分析等情况,将该病诊断为肠道亚种沙门氏菌引起的牦牛沙门氏菌病。     

A case–case study comparing the individual risk factors and symptomatology of Salmonella Heidelberg and Salmonella Typhimurium in Ontario in 2015, following implementation of the Ontario Investigation Tools

Salmonella Heidelberg and Salmonella Typhimurium are among the most common serotypes responsible for human salmonellosis in Ontario. Introduction of the Ontario Investigation Tools (OIT) in 2014 allowed for standardized case investigation and reporting. This study compared the risk factors and symptomatology for sporadic S. Heidelberg and S. Typhimurium cases reported in Ontario in 2015, following implementation of the OIT. Multilevel logistic regression models were applied to assess associations between serotype and individual‐level demographic characteristics, exposures and symptoms for sporadic confirmed cases of S. Heidelberg and S. Typhimurium in Ontario in 2015. There were 476 sporadic cases of S. Typhimurium (n = 278) and S. Heidelberg (n = 198) reported in Ontario in 2015. There were significant associations between the odds of the isolate from a case being one of these serotypes, and travel, consumption of sprouts (any type), contact with reptiles and development of malaise, fever or bloody diarrhoea. The S. Typhimurium and S. Heidelberg cases differed in both symptom presentation and risk factors for illness. Case–case comparisons of Salmonella serotypes have some advantages over case–control studies in that these are less susceptible to selection and recall bias while allowing for rapid comparison of cases to identify potential high‐risk exposures that are unique to one of the serotypes when compared to the other. Comparing cases of two different Salmonella serotypes can help to highlight risk factors that may be uniquely associated with one serotype, or more strongly associated with one serotype compared to another. This information may be useful for understanding relative source attribution between common serotypes of Salmonella.     

鼠伤寒沙门菌烈性噬菌体的分离鉴定与生物学特性

旨在分离鼠伤寒沙门菌烈性噬菌体,为控制该病原菌感染或污染提供生物制剂.以1株从市售散装牛奶中分离到的多重耐药性鼠伤寒沙门菌为宿主菌,采用人工诱导方法,连续1周每日给3只试验鸡饲喂宿主菌悬液,7 d后,采用双层琼脂平板法从试验鸡粪便中分离培养噬菌体,并对其效价、核酸类型、宿主谱、热稳定性与酸碱耐受性以及对鼠伤寒沙门菌感染...     

Fatal Chlamydia psittaci infection in a domestic kitten

Chlamydia psittaci has not been reported to cause disease in domestic cats, to our knowledge. In contrast, C. felis infection is common in domestic cats and typically results in conjunctivitis, upper respiratory tract infection, and less frequently pneumonia. Herein, we report the pathologic findings and diagnostic features of a fatal case of psittacosis in a 7-wk-old domestic kitten. The animal was 1 of a litter of 5 that, together with the queen, were yielded to a pet rescue center in Wyoming. Over a period of ~3 wk, the kittens and queen became sick, thin, and icteric prior to death, despite antimicrobial treatments. Postmortem evaluation of a kitten revealed necrosuppurative hepatitis with Gimenez stain–positive intracellular bacteria, nonsuppurative pneumonia, and mild leptomeningitis. The diagnosis of psittacosis was made by 16S rRNA PCR using multiple primer sets and sequencing from liver. Psittacosis should be considered a differential diagnosis in domestic cats with intracellular bacterial hepatitis and interstitial pneumonia.     

Parvoviral enteritis and salmonellosis in raccoons with sudden death

Eight of 9 juvenile raccoons at a rehabilitation center died without obvious prior clinical signs. Gross changes were unremarkable except for mildly distended intestines. Microscopically, crypt loss, distension, necrosis, and regeneration with intranuclear viral inclusions were observed in the small intestine, with marked lymphoid depletion and necrosis in Peyer patches and mesenteric lymph nodes. Immunohistochemistry with a canine parvovirus antibody showed intensive signals of parvoviral antigens in the crypts and lymphoid germinal centers. Metagenomic sequencing allowed assembly of a complete parvoviral genome with >99% identity to canine parvovirus 2a, as well as Salmonella enterica subsp. enterica. Also, S. enterica subsp. enterica serovar Thompson with multiple antimicrobial resistance was isolated from the intestinal contents. Concurrent infection with parvovirus and Salmonella should be included as a differential diagnosis in raccoons with sudden death.     

一株鼠伤寒沙门氏菌噬菌体的分离鉴定及对小鼠的防制效果研究

本研究旨在通过双层平板法从鸡粪中分离鼠伤寒沙门氏菌烈性噬菌体，并通过电镜观察、热稳定性、pH稳定性、最佳感染复数、一步生长曲线和在小鼠上的防制效果试验对噬菌体进行评估。结果显示，从鸡粪中成功分离出一株鼠伤寒沙门氏菌噬菌体（φBLCC8-0050-3），该噬菌体有一个正多面体立体对称的头部，头径直径约65 nm，无尾部结构，应属于盖噬菌体科（Tectiviridae）烈性噬菌体；噬菌斑成圆形空斑，周围有晕环，直径为2~3 mm；温度耐受范围是30~50℃；pH耐受范围为3~10。当感染复数（multiplicity of infection，MOI）为0.0001时，子代噬菌体滴度最高；按照一步生长曲线结果，潜伏期为20 min左右，爆发时间为180 min左右，爆发量为43 333 PFU/cell；从噬菌体对鼠伤寒沙门氏菌的防制效果来看，处理14 d后，阳性对照组小鼠存活率为0，噬菌体预防组小鼠存活率为90%，噬菌体治疗组小鼠存活率为70%。说明与阳性对照组相比，预防组和治疗组都对小鼠抵抗沙门氏菌感染有一定的作用。结果表明，φBLCC8-0050-3是一株具有良好应用前景的噬菌体，可作为一种生物抑菌剂用于鼠伤寒沙门氏菌的防制。     

Retrospective study on the occurrence of the feline lungworms Aelurostrongylus abstrusus and Troglostrongylus spp. in endemic areas of Italy

Aelurostrongylus abstrusus is a metastrongyloid nematode infesting the respiratory system of domestic cats worldwide. Troglostrongylus brevior and Troglostrongylus subcrenatus, two lungworms thought to infest wild felids, have been found recently in domestic cats from Spain and Italy. These unexpected findings have raised doubts about the assumed past and present occurrence of Troglostrongylus spp., especially T. brevior, in domestic hosts and suggest that there may have been missed detection or misdiagnosis. The present retrospective study evaluated the presence of lungworms in cats from Italy with a diagnosis of respiratory parasitism or with compatible lung lesions from 2002 to 2013. Sixty-eight samples of DNA and larvae from cats with a diagnosis of aelurostrongylosis, and 53 formalin-fixed paraffin-embedded lung samples from cats confirmed as lungworm infested or with compatible lesions, were investigated using two DNA-based assays specific for A. abstrusus or T. brevior. All DNA and larval samples were positive for A. abstrusus and one was additionally positive for T. brevior. Most paraffin-embedded lung tissues were positive only for A. abstrusus, but two samples tested positive for both lungworms and one for T. brevior only. This study supports the major role of A. abstrusus in causing feline respiratory parasitism in endemic areas of Italy.