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Zoonotic Babesia: possibly emerging pathogens to be considered for tick-infested humans in Central Europe.

The three host-tick Ixodes (I.) ricinus is regarded as an important vector of tick-borne microorganisms pathogenic for humans in central Europe and is primarily known as the main vector of Borrelia (B.) burgdorferi and the virus causing tick-borne encephalitis (TBE), the most clinically relevant tick transmitted pathogens for humans in European countries. Furthermore, it is now well established that I. ricinus also transmits Ehrlichia (E.) phagocytophila, Babesia (Ba.) divergens, and Ba. microti, all agents of zoonotic infections in dear, sheep, cattle, dogs, and horses. In addition to their known zoonotic potential, recent molecular-epidemiological and seroepidemiological surveys as well as increasingly reported clinical cases of infections caused by these tick-borne organisms other than B. burgdorferi (TOBB) also strongly suggest a possible relevance of Babesia, Ehrlichia and Rickettsia for humans at risk in Europe. However, there are few medical microbiological investigations and epidemiological data on the distribution and relevance of Babesia for humans in our part of the northern hemisphere. There is also very little diagnostic and clinical knowledge on human babesiosis in many regions of Europe. Furthermore, sophisticated diagnostic tools designed for the reliable detection of the underlying pathogens, are not yet generally available to the microbiological laboratory. This review aims to provide basic information on human babesiosis and the most relevant causative pathogens of the disease in Europe and to draw attention to this parasitic infection as a possibly emerging and probably under-diagnosed disease in this part of the northern hemisphere.

Animals↗

Characterization of intestinal cnf1+ Escherichia coli from weaned pigs.

Escherichia coli isolated from 204 cases of porcine postweaning diarrhoea were tested by PCR for the genes of cytotoxic necrotic factors (CNF) and of cytolethal dystending toxin (CDT). Selected strains were also examined by PCR for the presence of papC-, sfa-, f17-, f18-, and afa-specific sequences encoding P, S, F17, F18 fimbriae and afimbrial adhesins. A 5.9% (12/204) of the strains had cnf1 gene, and two of them had cdt gene as well. Further six cdt+ strains were detected which were cnf-negative. Most of the cnf1+ strains belonged to serogroups O2, O6, O8, O54 characteristic of necrotoxic E. coli (NTEC) of humans. All the cnf1+ strains possessed the genes for P or S fimbriae or both, but were negative for F4, F17, or F18 or afimbrial adhesins. Results suggest that these enteric isolates may have entero- and/or uropathogenic significance in weaned pigs, and may have zoonotic potential for humans.

Animals↗

Zoonotic babesiosis.

Zoonotic babesiosis has received increased attention recently, due mainly to the interest in tick-borne zoonotic diseases generated by the emergence of Lyme borreliosis and to increased awareness of diagnostic and treatment difficulties associated with co-infection cases. The vast majority of European cases have been caused by Babesia divergens in splenectomised patients, and although rare, this disease is very dangerous, requiring aggressive treatment. The use of atovaquone, a recently developed anti-protozoan agent for human treatment, may be considered in future cases. Most human babesiosis caused by B. microti have occurred in the north-eastern states of the USA and can affect spleen-intact as well as asplenic patients. The majority of infections are subclinical or follow a mild chronic course, but dangerous acute infections can occur in immunocompromised patients. The role of B. microti in apparently unresponsive cases of Lyme borreliosis and treatment of co-infections require further investigation. The zoonotic potential of B. microti in Europe is still unresolved, but the vector competence of Ixodes ricinus for at least some European (and American) strains has been demonstrated.

Animals↗

Circulation of avian Chlamydia abortus in the Netherlands and community-acquired pneumonia: an outbreak investigation and retrospective cohort study.

BACKGROUND: In 2021, a novel group of Chlamydia strains in wild birds was classified as avian Chlamydia abortus, with unknown zoonotic potential. We report relevant features of avian C abortus infections from a Dutch family cluster and unrelated historical cases using clinical, epidemiological, and microbiological data. METHODS: An outbreak of avian C abortus started in the Netherlands in December, 2022. Source investigation was done using questionnaires to interview patients and environmental sampling. The outbreak strain of avian C abortus was cultured from three patients from whom sufficient material was available for culture and underwent whole-genome analysis. The outbreak strains and retrospective cohort study strains previously submitted to the National Human Psittacosis surveillance programme in the Netherlands between 2010 and 2022 were typed by partial ompA sequencing. Strains with the same aberrant ompA genotype were further analysed with XerC gene plasmid analysis and compared with closely related Chlamydia sequences available in GenBank. FINDINGS: An avian C abortus strain caused a cluster of respiratory illness in four family members. Three patients were hospitalised with community-acquired pneumonia, one of whom was admitted to the intensive care unit. The faeces of wild birds were considered a probable source for the index infection. For two family members, human-to-human transmission was a plausible route. Ten historical cases could be identified with avian C abortus with the same ompA genotype. All patients had been admitted to hospital, at least five developed pneumonia, and one died. INTERPRETATION: This cluster supports that avian C abortus strains can cause human infections and underlines that human-to-human transmission should be considered when tracing the source of such infections. FUNDING: National Institute for Public Health and the Environment and Dutch Ministry of Agriculture, Fisheries, Food Security and Nature. TRANSLATION: For the Dutch translation of the abstract see Supplementary Materials section.

Humans↗

Subtype analysis of Cryptosporidium parvum isolates from calves on farms around Belgrade, Serbia and Montenegro, using the 60 kDa glycoprotein gene sequences.

Cryptosporidium parvum is composed of multiple subtypes, which appear to be zoonotic or anthroponotic. Therefore, in order to understand the molecular epidemiology of this species and to control the zoonotic transmission, it is essential to identify the isolates at the subtype level. In the present study, 60.2% of 103 examined dairy calves from 10 farms in the Belgrade area were positive for Cryptosporidium infection by PCR, and all of them were identified as C. parvum by PCR-RFLP of SSUrRNA and COWP genes. Eighteen C. parvum isolates selected randomly from 9 positive farms were classified by molecular phylogenetic analysis of the 60 kDa glycoprotein gene sequences into 3 subtype allele families, IIa and IId, which are known to be zoonotic, and a new family IIj. Furthermore 10 isolates in IIa were classified into 3 subtypes IIaA16G1R1b, IIaA18G1R1, IIaA20G1R1, 2 in IId into IIdA18G1b, and 6 in IIj into IIjA16R2 and IIjA17R2. The last 2 subtypes in IIa and 2 subtypes in IIj were new subtypes. These results suggest that C. parvum isolates harboured in calves in the Belgrade area have zoonotic potential and C. parvum is genetically diverse only in a limited area. This is the first molecular epidemiological report about Cryptosporidium infection in Serbia and Montenegro.

Animals↗

Molecular characterization of a Toxocara variant from cats in Kuala Lumpur, Malaysia.

The ascaridoid nematode of cats from Kuala Lumpur, Malaysia, previously identified morphologically as Toxocara canis, was characterized using a molecular approach. The nuclear ribosomal DNA (rDNA) region spanning the first internal transcribed spacer (ITS-1), the 5.8S gene and the second internal transcribed spacer (ITS-2) was amplified and sequenced. The sequences for the parasite from Malaysian cats were compared with those for T. canis and T. cati. The sequence data showed that this taxon was genetically more similar to T. cati than to T. canis in the ITS-1, 5.8S and ITS-2. Differences in the ITS-1 and ITS-2 sequences between the taxa (9.4-26.1%) were markedly higher than variation between samples within T. canis and T. cati (0-2.9%). The sequence data demonstrate that the parasite from Malaysian cats is neither T. canis nor T. cati and indicate that it is a distinct species. Based on these data, PCR-linked restriction fragment length polymorphism (RFLP) and single-strand conformation polymorphism (SSCP) methods were employed for the unequivocal differentiation of the Toxocara variant from T. canis and T. cati. These methods should provide valuable tools for studying the life-cycle, transmission pattern(s) and zoonotic potential of this parasite.

Animals↗

High prevalence of Enterocytozoon bieneusi in swine with four genotypes that differ from those identified in humans.

The microsporidial species Enterocytozoon bieneusi is found among immunocompromised, particularly HIV-infected, patients with chronic diarrhoea, and rarely also among immunocompetent persons with self-limited diarrhoea. Only recently, E. bieneusi was detected in 4 pigs in Switzerland raising the question of a potential zoonotic nature of this parasite. We examined faecal samples of 109 pigs, 24 cows, horses and red foxes each for the presence of E. bieneusi by PCR and compared these isolates with isolates obtained from stool samples of 13 HIV-infected patients living in Switzerland. In animals, E. bieneusi was only identified in pigs with a prevalence of 35%. Analysis of the rDNA internal transcribed spacer (ITS) sequence allowed the classification of E. bieneusi from 28 pigs into 4 distinct genotypes which grouped very closely (identity 96.3-98.8%) together with 2 of the 3 human-derived E. bieneusi genotypes. Hence, E. bieneusi seems to be a common parasite in swine, but no genotypes were identified that were found in humans. Nevertheless, swine might serve as a new animal model for enterocytozoonosis.

Animals↗

Occupational exposure to Streptococcus suis type 2.

Antibody titres to Streptococcus suis type 2 were measured with an enzyme linked immunosorbent assay (ELISA) in four occupational groups in New Zealand. No veterinary students, 9% of dairy farmers, 10% of meat inspectors and 21% of pig farmers were seropositive to S. suis type 2. The development of antibody to S. suis type 2 was associated with occupational contact with pigs or their meat products. Subclinical infection with S. suis type 2 appears to occur in humans and the antibody produced is of only short duration. The annual incidence of subclinical infection and seroconversion in pig farmers may approach 28%. Thus S. suis type 2 may be one of the most infectious potentially zoonotic agents present in New Zealand, although very rarely resulting in clinical disease.

Animal Husbandry↗

Seasonal distribution of Rhipicephalus sanguineus ticks (Acari: Ixodidae) on dogs in an urban area of Morelos, Mexico.

Between 1993 and 1995, we examined 1742 dogs at two veterinary clinics in Cuernavaca City in Mexico for the presence of Rhipicephalus sanguineus ticks. The overall tick infestation prevalence was 20% and there were no significant differences (p > 0.05) between different years. The prevalence was somewhat higher in spring, summer and autumn (20% or more) than in winter (13.7%). A positive correlation (p < 0.01) was found between prevalence of ticks and rainfall in spring, summer and autumn, whereas in winter there was only a correlation with temperature. Different stages of the tick were found and it was calculated that 2.5 generations could be completed each year. It is concluded that the environmental conditions of Cuernavaca City favour development and maintenance of R. sanguineus ticks throughout the year and that its role as a vector of diseases poses a threat to dogs and may have potential zoonotic risks.

Animals↗

Sporothrix schenckii isolated from domestic cats with and without sporotrichosis in Rio de Janeiro, Brazil.

A total of 148 cats with a clinical and mycologic diagnosis of sporotrichosis and 84 apparently healthy cats with domiciliary contact with the affected animals were studied. Sporothrix schenckii was isolated from 148 (n = 148; 100%) clinical samples of cutaneous lesion (biopsy, swab or aspiration of purulent secretion), 47 (n = 71; 66.2%) nasal cavities, 33 (n = 79; 41.8%) oral cavities, and 15 (n = 38; 39.5%) nails of cats with sporotrichosis. Histopathological examination revealed yeast-like structures in 50 (n = 70; 71.4%) of the biopsies studied. S. schenckii was isolated from the blood culture of one cat (n = 5, 20%) with the disseminated cutaneous form of the disease. On another occasion, the fungus was isolated from the testis of one (n = 7; 14.3%) of the animals submitted to sterilization. In the group of cats with domiciliary contacts, 3 (n = 84; 3.57%) oral swabs showed positive cultures. Isolation of S. schenckii from different clinical specimens during both the clinical and preclinical phase reinforces the zoonotic potential of feline sporotrichosis.

Animals↗

Occurrence of yeasts in psittacines droppings from captive birds in Italy.

Three-hundred twenty five droppings from parrots raised in the premises of 4 breeders and in several private households were cultured for yeasts. One-hundred sixty droppings (49.2%) resulted positive. From these specimens 212 isolates belonging to 27 different species were obtained. Mainly Candida species such as C. albicans, C. catenulata, C. curvata, C. famata, C. glabrata, C. guilliermondi, C. holmii, C. intermedia, C. krusei, C. lambica, C. lusitaniae, C. membranaefaciens, C. parapsilosis, C. pelliculosa, C. sake and C. valida were isolated. Debarvomyces marama, D. polymorphus, Geotrichum sp., Pichia etchelsii, P. ohmeri, Rhodotorula glutinis, R. rubra, Rhodotorula sp., Saccharomyces cerevisiae, S. kluyiveri and Zygosaccharomyces sp. were also obtained. Dark colonies on Staib medium were never observed. The psittacine birds apparently serve as carriers for several Candida species or their perfect states and to a lesser extent for other opportunistic yeasts such as Rhodotorula, Trichosporon and Saccharomyces spp., which are considered part of the transient microbiota of the gastrointestinal tract. The most striking finding was the absence of Cryptococcus spp. among the isolates. The present survey confirms the role of pet birds in carrying potential zoonotic yeasts.

Animals↗

Pathogenesis of BSE.

Before the emergence of bovine spongiform encephalopathy (BSE) and recognition of its zoonotic potential, the major example of the transmissible spongiform encephalopathies (TSEs) of animals was scrapie of sheep. But there is no evidence that scrapie transmits naturally to any species other than sheep and goats. The pathogenesis of scrapie has been studied most in experimental laboratory rodent species. In most experimental models of scrapie, after peripheral non-neural routes of infection, replication of the agent can first be detected in lymphoreticular system (LRS) tissue. When the route of introduction of agent into the body is localized, initial involvement will be in LRS tissue draining the infection site. Thereafter, there is a striking amplification of the agent in the LRS and spread by lymphatic/haematogenous routes, giving widespread dissemination in the LRS. This precedes replication in the CNS, but is not the means by which infection reaches the CNS. There is now substantial evidence from experimental models of scrapie that involvement of the CNS is by peripheral nervous system (PNS) pathways. In some models employing oral exposure the earliest localized LRS replication is in the gut-associated lymphoid tissue (GALT) and autonomic PNS routing to the CNS has been implicated. However, the relative importance of different routes of spread of TSEs within the body is determined by a number of host- and agent-dependent factors and, therefore, generalizations from an experimental model to a natural disease across a species barrier may not be appropriate. With the occurrence of BSE and recognition of its food-borne route of transmission via meat and bone meal, has come greater awareness of the probable importance of the oral route of infection in ruminant species affected by TSEs. In consequence, studies have increasingly focused on the natural host species to examine pathogenetic events.

Animals↗

First report on the occurrence of 'Helicobacter heilmannii' in the stomach of rabbits.

Gastric Helicobacter spp. have been described in a wide range of animal species, including dogs, cats, primates, swine, cattle and rodents. However, in lagomorphs--more specifically rabbits--gastric Helicobacter infections have never been reported. Biopsy specimens were collected from different stomach regions of 23 rabbits, including 10 pet rabbits, 10 industrial animals and 3 research animals. These were subjected to a PCR assay for the detection of Helicobacter DNA. Identification up to the species level was based on 16S rRNA sequence analysis and a recently developed multiplex PCR. Seven rabbits (four pet, one research animal and two industrial animals) tested positive in the Helicobacter genus-specific PCR in the stomach, with the corpus being predominantly positive. H. felis and H. salomonis, hitherto presumed to be naturally hosted by cats and dogs, were detected in three animals and one animal, respectively. One of these animals had been completely devoid of any form of contact with cats or dogs. A H. pullorum/H. rappini-like organism (96% 16S rDNA sequence similarity) was found in an industrially held rabbit. The helicobacters of the two remaining rabbits could not be identified up to the species level. To conclude, this is the first report on the occurrence of Helicobacter spp. in the stomach of rabbits. In view of the fact that H. felis and H. salomonis are put forward as having zoonotic potential, further research is necessary to investigate the implications of these findings not only for the rabbit but also for human health.

Animals↗

[Abortion in humans caused by Chlamydophila abortus (Chlamydia psittaci serovar 1)].

On a farm housing cattle and goats an abortion storm occurred affecting 50% of the goats during the lambing season 2000/2001. In one of three investigated caprine abortions Chlamydophila abortus could be identified as etiology. During this time a pregnant woman (pregnancy week 19/20) had contact with aborting goats. She developed a severe generalized infection and aborted. The placenta contained Chlamydophila abortus shown by immunohistochemistry and PCR. Aim of the present case report is to alert veterinarians about the potential zoonotic risk of ovine/caprine abortions.

Abortion, Spontaneous↗

[Travel medicine of parasitic diseases in the dog].

Companion animals are increasingly brought along by their owners to foreign countries. Thus, small animal travel medicine is becoming more important. The field includes both prophylaxis and metaphylaxis against various infectious diseases, as well as their diagnosis and treatment. Dogs returning from Southern Europe, but also from more tropical regions, may be infected with exotic pathogens. In addition, imported pedigree or working dogs, and especially stray dogs imported through welfare organisations, are at high risk. The present overview summarises the clinical and practical aspects of exotic parasitic diseases that may affect such dogs, and the risk of such diseases becoming autochthonously transmitted in Switzerland. Furthermore, the zoonotic potential of these infections will be considered.

Animal Welfare↗

Characterization and evolutionary history of novel SARS-CoV-2-related viruses in bats from Cambodia.

Circulating bat coronaviruses present a significant pandemic threat, yet our understanding of their genetic diversity and evolutionary dynamics remains limited. Over 3 years, we sampled 1,462 bats in Cambodia's Steung Treng province, identifying extensive and diverse coronaviruses co-circulation. Using metatranscriptomic and amplicon sequencing, we generated 33 complete sarbecovirus genomes sequences, revealing novel lineages that cluster into four distinct groups, each associated with different Rhinolophus bat species. Our analysis highlights rapid migration and recombination of sarbecovirus lineages over short distances and timescales. Of note, the receptor-binding domains of two novel viral groups exhibit high similarity to SARS-CoV-2, and pseudovirus assays confirmed the ability of this spike protein to mediate entry into cells expressing human ACE2, suggesting a potential zoonotic risk. The observed genetic diversity underscores the urgent need for continuous surveillance to identify high-risk animal-to-human interfaces and inform pandemic preparedness.

Animals↗

Extragastric Helicobacter species.

The genus Helicobacter has expanded at a rapid pace and no fewer than 31 species have been named since the proposal of the genus in 1989. Of these 31 species, 22 are principally associated with extragastric niches and there is increasing interest in the role of these taxa in diseases of humans and animals. Substantial evidence attests to certain species playing a role in the pathogenesis of enteric, hepatic and biliary disorders and some taxa demonstrate zoonotic potential. The importance of extragastric Helicobacters is likely to be an important topic for research in the near future. Here, important papers published in the field this last year are reviewed.

Animals↗

Zoonotic parasite infections of the Arabian sacred baboon Papio hamadryas arabicus Thomas in Asir Province, Saudi Arabia.

Evidence of zoonotic parasite infection was recorded in the faeces of the Arabian Sacred Baboon in human populated residential and non-residential areas in Asir, Southwestern Saudi Arabia. Cysts of Giardia intestinalis and Entamoeba histolytica, and ova of Hymenolepis nana, Enterobius vermicularis, Ascaris sp., Trichuris sp., and a hookworm were encountered in 45 (about 39%) of 115 faecal samples examined. A higher rate of infection was observed in the residential areas. Most of the parasites recovered in the baboons were also found to infect humans in these areas. Since this primate has previously been reported to be of zoonotic potential, it is suggested that serious measures should be brought into effect to prevent human-baboon contact in the areas investigated.

Animals↗