Foodborne outbreak of Salmonella subspecies IV infections associated with contamination from bearded dragons

Approximately 1.4 million Salmonella infections and 400 deaths occur annually in the United States. Approximately 6% of human Salmonella cases are thought to be associated with reptiles; Salmonella enterica subspecies IV is primarily reptile-associated. During 1-4 December, 2009, three isolates of Salmonella IV 6,7:z4,z24:- with indistinguishable pulsed-field gel electrophoresis (PFGE) patterns were identified through Minnesota Department of Health laboratory-based surveillance. None of the three patients associated with the isolates reported reptile contact; however, all had attended the same potluck dinner. Dinner attendees were asked questions regarding illness history, foods they prepared for and consumed at the event, and pet ownership. Cases were defined as illness in a person who had eaten potluck food and subsequently experienced fever and diarrhoea (three or more loose stools in 24 h) or laboratory-confirmed infection with Salmonella IV matching the outbreak PFGE subtype. Nineteen days after the event, environmental samples were collected from a food preparer's house where two pet bearded dragons were kept. Sixty-six of 73 potluck food consumers were interviewed; 19 cases were identified; 18 persons reported illness but did not meet the case definition. Median incubation period was 19 h (range: 3-26 h). Median duration of illness was 5 days (range: 1-11 days). Consumption of gravy, prepared by the bearded dragons' asymptomatic owner, was associated with illness (16/32 exposed versus 1/12 unexposed; risk ratio: 6.0; exact P = 0.02). Salmonella Labadi was recovered from 10 samples, including from one bearded dragon, the bathroom door knob and sink drain, and the kitchen sink drain. The outbreak PFGE subtype of Salmonella subspecies IV was isolated from vacuum-cleaner bag contents. This foodborne outbreak probably resulted from environmental contamination from bearded dragons. Reptiles pose a community threat when food for public consumption is prepared in households with reptiles.     

Medical management of Rhodococcus equi infections: A clinical epidemiology perspective

Rhodococcus equi infections cause severe pulmonary disease in foals, affecting animal welfare and increasing production costs in horse-breeding farms. Extra-pulmonary disorders (EPD) are relatively common and can occur independently of pulmonary disease; foals with EPD have a more guarded prognosis. The accompanying paper by Shaw et al. (2021) reports the successful diagnosis and medical treatment of a large abdominal abscess caused by R. equi infection. The authors report on the benefits of using gallium maltolate, a semimetal compound with antimicrobial activity, in combination with traditional R. equi infection antimicrobial treatment (combination of a macrolide and rifampicin). Experimental studies are needed to understand further the benefits of this combined therapy, to evaluate the synergistic effects and if it improves the concentration of antimicrobial drugs into infected tissues. The publication of this case report in Equine Veterinary Education is of clinical importance to equine practitioners when diagnosing and treating R. equi infected foals with or without EPD.     

Imaging suppurative infections of the central nervous system in horses

Suppurative infections are typically caused by pyogenic bacteria, and are characterised by the formation of purulent exudates (pus). These infections may occur anywhere in the body and are particularly life‐threatening when pertaining to the central nervous system (CNS). Suppurative infections of the CNS may be due to trauma, local extension of disease, and haematogenous spread. In horses, suppurative infections are an important cause of morbidity and mortality, but only infrequently involve the CNS. The gross morphology of suppurative inflammation is described as phlegmon, abscess and empyema, with each form having characteristic morphological features that may be identified during advanced imaging of the CNS. In horses with known or suspected suppurative infection of the CNS, imaging may be performed to reduce diagnostic uncertainty, determine prognosis, or to describe the character and extent of the disease to guide case management.     

Longitudinal study of Salmonella infection in Italian farrow-to-finish swine herds

A longitudinal study of Salmonella enterica infection was carried out in five Italian farrow-to-finish swine herds previously known to be infected by Salmonella. Five litters were randomly selected from each herd and in each litter six piglets were randomly selected and individually identified. Thus, the study included 30 pigs from each farm. At weaning, individual blood samples were collected for serological examination from all selected piglets and on the same day from all sows in the farrowing unit. Piglets were bled again at approximately 60, 90, 150, 210 and 270 days of life whereas the last blood sample was collected at slaughtering. In one of the herds, in which the duration of productive cycle was about 12 months, the last blood samples were collected at 350 days of life. With the same time scheduling, five pen pooled faecal samples were collected from each herd for bacteriological examination. At slaughtering, mesenteric lymph nodes were collected from each ear-tagged pig. Sero-prevalence (cut off S/P ratio 0.25) in sows varied from 93.8% to 100%. In four herds, sero-prevalence in piglets showed a similar profile with complete decline of maternal antibodies at day 60 and clear sero-conversion between day 90 and day 150. In one herd, sero-conversion was observed earlier and 56% of piglets were positive at day 90. The peak of sero-prevalence was observed between day 210 and day 270. Sero-prevalence at slaughtering varied from 66% to 100%. Salmonella was isolated from faecal samples in four of five herds. No Salmonella was isolated from mesenteric lymph nodes at slaughter in two of the herds. Culture prevalence from mesenteric lymph nodes in the other three herds ranged from 3.3% to 30%. This longitudinal study provides original information about epidemiological dynamics of Salmonella enterica infection in Italian swine herds in consideration of the unique extended fattening period typical of the Italian production.     

Salmonella Dublin infection in Queensland dairy cattle

Objective: To investigate the presence of Salmonella Dublin in Queensland cattle.
Design: An epidemiological study using diagnostic laboratory information and farm records.
Procedure: Outbreaks of gastroenteritis or pneumonia in calves, and abortions and enteritis in cows were routinely investigated for the presence of salmonellae. Where S Dublin was isolated, attempts were made to gather further epidemiological information.
Results: Prior to 1983 only two outbreaks of S Dublin have been recorded in Queensland dairy cattle. In 1983 S Dublin abortions were diagnosed in dairy heifers introduced from southern Australia to south-east Queensland. Sampling indicated that at least 10% of the 500 introduced heifers were faecal excretors of S Dublin. On 3 of the 7 farms from which S Dublin was recorded, infection spread to other cattle that were in contact. From February 1985 to February 1996, 29 outbreaks of S Dublin in cattle occurred on 29 farms (28 in south east Queensland and 1 in north Queensland). Calves were primarily affected. Continuing outbreaks were confirmed on only 4 of these 29 farms. On 15 farms S Dublin infections were associated with the purchase of infected calves or cows, while another farm adjoined 2 previously infected farms. No source of S Dublin was evident for the other 13 farms, where histories were often inadequate.
Conclusion: There has been a marked increase in S Dublin outbreaks in Queensland dairy cattle since 1983. Introduction of S Dublin carrier and aborting dairy heifers from southern Australia, where S Dublin is not uncommon, was associated with the initial outbreaks.     

Meningoencephalomyelitis in a foal due to Salmonella agona infection

CASE HISTORY: A neonatal Thoroughbred foal was presented with rib fractures and left forelimb lameness secondary to dystocia.

CLINICAL FINDINGS: The foal developed a head tilt, seizures and watery diarrhoea during hospitalisation and died at 7 days of age. Histological examination of the brain and spinal cord revealed a suppurative meningoencephalomyelitis with vasculitis, and numerous intralesional, gram-negative bacilli. Similar microscopic lesions were noted in the lungs, renal medullary interstitium, and umbilicus. Bacilli in the brain, spinal cord and umbilicus were identified immunohistochemically as Salmonella group B. Salmonella agona was isolated in pure culture from the brain, lung, liver, kidney, and intestine.

CONCLUSION: This is the first report of meningoencephalomyelitis and septicaemia due to Salmonella infection in an equine neonate.     

Some aspects of the epidemiology and control of Salmonella typhimurium infection in outwintered suckler cows.

Two outbreaks of Salmonella typhimurium infections affected outwintered, spring-calving suckler cows in late pregnancy. The infections spread rapidly both within and between groups of stock on the affected farms, with morbidity in the infected groups varying from 14.5 per cent to over 60 per cent, and mortality in adult cattle varying from 0 to 14.3 per cent. Prophylactic measures included the use of antibiotics and killed vaccines against Escherichia coli, Salmonella dublin, S typhimurium, and Pasteurella multocida. In one outbreak, use was also made of a polyvalent serovaccine and hyperimmune serum against E coli, S typhimurium, and S dublin. In both outbreaks no new cases were reported in the affected groups after the administration of the second dose of vaccine, and there was no resurgence of disease on the affected farms within 18 months of the primary outbreaks.     

Exercising arrhythmias and sudden cardiac death in horses: Review of the literature and comparative aspects

Arrhythmias are common in equine athletes during and immediately after exercise. Many of these rhythm variations are not clinically relevant. In horses, a link between different exercising arrhythmias and poor performance or between exercising arrhythmias and sudden cardiac death (SCD) is strongly suspected but not fully understood or proven. SCD during races or competitions is rare, but has catastrophic consequences for the safety of the human partner and public perceptions of welfare during equestrian sports. This review summarises current knowledge of equine exercise arrhythmias and their implications in SCD and compares existing principles and recommendations for equine subjects with those for human athletes.     

Injuries and outcome of three horses hospitalised in the aftermath of Hurricane Isaac

This case series describes 3 horses rescued from flooded areas, hospitalised and treated at the Louisiana State University Veterinary Teaching Hospital in the wake of Hurricane Isaac. The purpose of the paper is to familiarise practitioners with the injuries that may be found in flood‐afflicted horses and livestock. Case 1 presented with a degloving injury of the right hindlimb. The gelding developed neurological signs and was subjected to euthanasia; necropsy was consistent with Salmonella sepsis and disseminated mycosis due to Candida krusei, the first case reported in a horse. Case 2 presented with dermatitis attributable to chemical exposure and pneumonia and was subjected to euthanasia due to severe bilateral laminitis. Case 3 sustained a degloving injury of the left hindlimb and was subjected to euthanasia due to intractable pain. This case series illustrates the need for preparation and evacuation to avoid life‐threatening injuries in equids and livestock caused by hurricanes and their aftermath.     

Atypical myopathy in the South-East of England: Clinicopathological data and outcome in hospitalised horses

This retrospective case series describes clinicopathological data and outcome of hospitalised atypical myopathy (AM) cases in the South-East of England. The study aimed to describe the frequency of metabolic abnormalities (hyperglycaemia, hyperlactataemia, hypertriglyceridaemia) and outcome in AM cases in the South-East of England and test the hypothesis that serum creatine kinase (CK) activity and blood glucose, lactate and triglyceride concentrations are associated with outcome. Medical records (2011–2017) from three referral hospitals were reviewed for cases with a clinical diagnosis of AM. A previously described algorithm was applied and cases were included if a diagnosis of AM was considered highly likely. In cases admitted after 2013 known or possible exposure to sycamore trees was also required for inclusion. Sixty-four animals were included, 44% (28/64) survived. Hyperglycaemia, hyperlactataemia and hypertriglyceridaemia were present in 76%, 89% and 92% of horses on admission, respectively. Survivors had lower blood lactate concentrations (survivors: median 3.5 mmol/L; range 0.5–10.4 mmol/L vs. nonsurvivors: median 7.3 mmol/L; range 2.5–16.5 mmol/L; P = 0.011) and serum CK activities (survivors: median 38,369 U/L; range 7024–570,498 U/L vs. nonsurvivors: median 172,687 U/L; range 2036–570,953 U/L; P = 0.027) on admission when compared to nonsurvivors. Increasing CK activity (P = 0.008) and triglyceride concentrations (P = 0.038) during hospitalisation were associated with nonsurvival. More nonsurvivors required sedation (18/29; 62.1% vs. 4/22; 18.2%; P = 0.002). The prognosis for hospitalised horses with AM is guarded and outcome in this population was associated with admission CK activity and lactate concentrations, and increasing CK activity and triglyceride concentrations and need for sedation during hospitalisation.     

The prevalence and epidemiology ofAnoplocephala perfoliata infection in Norway

The caecum and the adjacent 30 cm lengths of ileum and large colon of 201 horses from two different regions of Norway (Østlandet and Trøndelag) were examined for the presence ofAnoplocephala perfoliata. In all, 20% of the horses were infested with the cestode (27% in Østlandet and 7% in Trøndelag). The mean number of worms in infected horses from the two regions was 18 and 6, respectively.Information was obtained on the age, sex, breed, type of pasture and anthelmintic treatment after the grazing season for 183 of the 20 horses. The degree of infestation withA. perfoliata was not influenced by age, breed or sex. The odds ratio (confidence limits) for using permanent pastures that had been grazed by horses for at least the 5 last years in succession was 8.8 (3.2–24.4). There was a significantly higher prevalence ofA. perfoliata infestation in Østlandet (odds ratio 3.1 (1.1–9.1). The relatively low prevalence ofA. perfoliata infestation in Norwegian horses compared to the reported prevalences in other countries and the differences in the prevalence between Østlandet and Trøndelag are discussed. Gross pathological examination identified lesions such as mucosal thickening, hyperaemia and/or erosions. These lesions were found in all of the infected horses, compared with only 5% of the non-infected horses.Examination of faecal samples from 26 of the infected horses detected cestode eggs in only three cases. It was concluded that faecal examination is an inadequate method for the diagnosis ofA. perfoliata infestation.     

Control of strongylosis in horses by alternate grazing of horses and sheep and some other aspects of the epidemiology of Strongylidae infections

Alternate grazing of horses and sheep as a control measure for gastrointestinal helminthiasis was studied in three grazing experiments in 1981, 1982 and 1983. Each year a group of three mare yearling Shetland ponies, which were kept on a small pasture from spring to autumn, were compared with a similar group which grazed a similar or the same pasture until July and were subsequently removed to a similar pasture which had been grazed by sheep from April to July. In addition both groups were treated with an anthelmintic when the latter group was removed to the sheep pasture. Pasture larval counts and worm counts and, in 1982 and 1983, faecal egg counts, clinical condition, total protein, albumin and beta-globulin levels demonstrated that the groups removed to sheep pasture acquired considerably lower burdens of nematodes of the subfamilies Cyathostominae and Strongylinae, but considerably higher burdens of Trichostrongylus axei than the groups which were not moved. These T. axei infections resulted in higher serum pepsinogen levels in the former groups compared to the latter in 1981 and 1982. At necropsy an important part of the T. axei burdens and, in 1982 and 1983, the Cyathostominae burdens consisted of inhibited early third stage larvae. A total of 20 species of the subfamily Cyathostominae and 7 species of the Strongylinae were found. Generally the composition of species was in agreement with other observations in western Europe, the most common species being: Cylicostephanus longibursatus, Cylicostephanus minutus, Cylicostephanus calicatus, Cylicostephanus goldi, Cylicostephanus poculatus, Cyathostomum labratum, Cyathostomum coronatum, Cyathostomum catinatum, Cylicocyclus leptostomus, Cylicocyclus nassatus, Cylicocyclus insigne, Strongylus edentatus and Strongylus vulgaris.     

Evidence‐based considerations for control of Parascaris spp. infections in horses

Parascaris spp. infection is virtually ubiquitous in young foals and worm burdens can achieve high numbers. The most important disease manifestation is impaction of the small intestine, which occurs in a small proportion of infected foals but is associated with a guarded prognosis for survival. Control of Parascaris spp. is complicated by emerging resistance to currently available anthelmintic drug classes. Resistance to macrocyclic lactones has been reported worldwide and a few studies have also documented signs of resistance to pyrantel salts and benzimidazoles. Foals generally develop immunity to Parascaris spp. parasites around age 6 months, but a proportion of weanlings and yearlings can harbour smaller burdens at age 8–10 months. Older horses have occasionally been reported with substantial ascarid burdens as well. Qualitative detection of ascarid eggs has good diagnostic value whereas an actual egg count does not correlate well with the size of the worm burden. A recent investigation documented the applicability of a transabdominal ultrasound technique for semiquantitatively monitoring ascarid burdens in foals. Control of ascarids is complicated by the limited drug classes available for treating this parasite, and by the fact that foals are often concurrently infected with strongyles. In many cases, none of the 3 available anthelmintic classes are simultaneously effective against both parasite groups, so close monitoring is required to select the most appropriate anthelmintic in each case.     

脉冲场凝胶电泳在沙门氏菌流行病学中的应用

脉冲场凝胶电泳是20世纪80年代发展起来的一种可用于分离10 kb至10 Mb分子质量DNA的新型凝胶电泳技术,已广泛应用于细菌分子分型、种群特异性鉴定及遗传分析等方面。文章介绍了脉冲场凝胶电泳的技术、应用状况及目前沙门氏菌的分型现状,并阐述了该技术在沙门氏菌流行病学研究方面的应用及发展前景。     

Overview of the use of antimicrobial drugs for the treatment of bacterial infections in horses

The use of antimicrobials in veterinary medicine is under great scrutiny with the emergence of antimicrobial resistance in the human population. Equine veterinarians rely on antimicrobials as an essential tool for the treatment of infections in horses, but there is much criticism of some use, particularly prophylaxis. While the appropriate use of antimicrobials can be justified in equine medicine, the misuse cannot. The definition of appropriate use is complex and involves the indication for therapy, antimicrobial selection, dosing regimen and timing and route of administration, duration of therapy and modification of therapy based on microbial susceptibility and clinical response. The aim of this article is to provide guidance on these factors to assist equine veterinarians in determining what constitutes appropriate antimicrobial use in horses.     

Comparison of two control systems for cyathostome infections in the horse and further aspects of the epidemiology of these infections

The small strongylid infections of two groups of three yearling female Shetland ponies and one yearling Shetland tracer pony were studied. One group was set stocked from April to November and was treated monthly with 5 mg kg-1 albendazole from two days before turnout until July. The other group grazed similar pasture until July, was treated with 5 mg kg-1 albendazole and subsequently removed to pasture grazed by sheep from April to July. The tracer ponies were added to both groups in September. The efficacy of both methods was not completely satisfactory probably because of low efficacy of anthelmintic treatment. There were no significant differences between the cyathostome burdens of the two groups. A high proportion of the cyathostome populations of all ponies consisted of inhibited early third stage larvae (L3). The finding of low numbers of immature fifth-stage worms in the tracer ponies indicated that the considerable adult burdens in the permanent ponies originated from infection picked up before the tracer ponies were added. In the group which was removed to sheep pasture after treatment in July it was likely that the majority of the adult worm burden had been ingested as infective larvae before treatment.     

Descriptive epidemiology of joint injuries in Thoroughbred racehorses in training

Reasons for performing study: No large scale epidemiological studies have previously quantified the occurrence of carpal, metacarpo‐ and metatarsophalangeal (MCP/MTP) joint injuries in Thoroughbred racehorses. Objectives: To develop an objective classification system for carpal and MCP/MTP joint injuries and estimate the incidence of these injuries in young Thoroughbreds in flat race training. Methods: In a prospective cohort study, data on daily exercise and veterinary‐diagnosed carpal and MCP/MTP joint injuries were collected from Thoroughbreds monitored since starting training as yearlings, for up to 2 years. Cases were classified in one of 4 categories: 1) localised to a carpal or MCP/MTP joint based on clinical examination and/or diagnostic analgesia; no diagnostic imaging performed; 2) localised to a carpal or MCP/MTP joint based on clinical examination and/or diagnostic analgesia; radiographs taken but no abnormalities detected; 3) evidence of abnormality of subchondral bone and/or articular margin(s) on diagnostic imaging and 4) evidence of discontinuity of the articular surface on diagnostic imaging. Incidence rates and rate ratios were estimated using Poisson regression, adjusting for trainer‐level clustering. Results: A total of 647 horses from 13 trainers throughout England contributed 7785 months at risk of joint injury. One‐hundred‐and‐eighty‐four cases of carpal (n = 82) or MCP/MTP (n = 102) joint injury were reported in 165 horses and classified in Category 1 (n = 21), Category 2 (n = 21), Category 3 (n = 72) or Category 4 (n = 70). The overall joint injury rate was 1.8 per 100 horse months (95% CI = 1.2, 2.8); rates did not differ significantly between 2‐ and 3‐year‐olds but females sustained Category 1 injuries at triple the rate of males (P = 0.03). Joint injury rates differed significantly between trainers (P<0.001) and there was trainer variation in anatomical site and severity of injury. Conclusions and potential relevance: Carpal and MCP/MTP joint injuries are an important cause of morbidity in Thoroughbred racehorses. Identification of modifiable risk factors for these injuries may reduce their incidence.     

Overview of the use of antimicrobials for the treatment of bacterial infections in horses

Use of antimicrobial drugs is central to the treatment of primary and secondary bacterial infection in horses. When selecting an antimicrobial to treat confirmed or suspected bacterial infection multiple factors should be considered, including: the likely infectious agent; distribution and dosage of selected drugs; mechanisms of action; and potential side effects. Many of these issues will be covered in subsequent articles in this series. The aim of this paper is to aid the clinician in the rational selection of antimicrobials by reviewing the mode of action, spectrum of activity, pharmacokinetics, pharmacodynamics, indications and potential side effects of the main classes of antimicrobial drugs. Extralabel use of drugs is common in veterinary medicine due to a lack of licensed products. This increases the importance of a thorough understanding of antimicrobials and their possible adverse effects.