Zoonotic Risk For Humans Research Articles

Epidemiology of infections due to zoophilic dermatophyte trichophyton simii, an update

Trichophyton simii is an important zoophilic dermatophyte. It has two different names, one for the asexual form (the anamorph state) that occurs in the vertebrate host, and the other for the sexual form (teleomorph also called “perfect state”) produced by mating between anamorphs. The sexual state of T. simii belongs to the genus Arthroderma in the family Arthrodermataceae of the phylum Ascomycota of the Kingdom fungi. Zoophilic Trichophyton species include Trichophyton equinum, T. bullosum, members of the T. mentagrophytes complex, T. simii, and T. verrucosum. The clinical lesions caused by T. simii in humans and animals are usually inflammatory and erythematous. It can be distinguished from other Trichophyton species by its faster growth on agar media, forming finely granular colonies with white-to-pale yellow color on reverse and distinctive to fusiform 3–7 septate macroconidia converting into chlamydospores in older cultures, and pyriform microconidia, and inability to perforate hair in-vitro, and produce the enzyme urease . Trichophyton simii is known to infect monkeys, chickens, dogs, and humans worldwide, though infections are sporadic and epidemic potential and zoonotic risk for humans is low; this dermatophyte is also known to occur as a geophilic species in several countries. The literature search generated a lot of data on T. simii infections from several countries, namely India, Sri Lanka, Japan, Iraq, Iran, Saudi Arabia, Belgium, France, the USA, and Brazil; many of the reports lacked details of clinical lesions and did not mention about treatment/outcome of infections. The results are analyzed and presented concisely in the tables. There is need for investigating the epidemiology of T. simii infections in countries from where, human T. simii infections have been reported, and occurrence of this dermatophyte in soil by employing conventional mycological methods and a newly developed PCR technique based on ITS genomic sequences of this dermatophyte.

Association of TLR2 haplotypes encoding Q650 with reduced susceptibility to ovine Johne\u2019s disease in Turkish sheep

Ovine Johne’s disease (OJD) is caused by Mycobacterium avium subsp. paratuberculosis (MAP) and carries a potential zoonotic risk for humans. Selective breeding strategies for reduced OJD susceptibility would be welcome tools in disease eradication efforts, if available. The Toll-like receptor 2 gene (TLR2) plays an important signaling role in immune response to MAP, and missense variants are associated with mycobacterial infections in mammals. Our aim was to identify and evaluate ovine TLR2 missense variants for association with OJD in Turkish sheep. Eleven TLR2 missense variants and 17 haplotype configurations were identified in genomic sequences of 221 sheep from 61 globally-distributed breeds. The five most frequent haplotypes were tested for OJD association in 102 matched pairs of infected and uninfected ewes identified in 2257 Turkish sheep. Ewes with one or two copies of TLR2 haplotypes encoding glutamine (Q) at position 650 (Q650) in the Tir domain were 6.6-fold more likely to be uninfected compared to ewes with arginine (R650) at that position (CI95 = 2.6 to 16.9, p-value = 3.7 × 10–6). The protective TLR2 Q650 allele was present in at least 25% of breeds tested and thus may facilitate selective breeding for sheep with reduced susceptibility to OJD.

Prevalence of Hepatitis E Virus (HEV) Antibodies in Mexican Pigs.

The hepatitis E virus (HEV) is the causative agent of Hepatitis E, an enterically transmitted disease. HEV infections in pigs and humans have been reported worldwide, but data from Mexico are scarce. In the present study, the prevalence of anti-HEV IgG antibodies was investigated in a quite large number of swine from Mexico by means of an ELISA based on a recombinant open reading frame 2 protein of HEV genotype 3. Serum samples from 683 healthy pigs (1-48months old), collected during 2010-2013 in 109 herds from 48 municipalities located in 9 states in the centre of the country were assayed. A 30.75% (210/683) of the sera tested were positive, and they were distributed along all the states included in the study. The prevalence of anti-HEV antibodies varied widely between municipalities and herds, and it was higher in pigs 4-6months of age. No relationships were detected between seroprevalences and farm characteristics. Forty individual faecal samples were analysed by RT-PCR and all resulted negative. These data indicate that HEV infection is widespread in Mexican pigs; thus, representing a potential zoonotic risk for humans.

EcoR Phylogenetic Analysis and Virulence Genotyping of Avian PathogenicEscherichia coliStrains andEscherichia coliIsolates from Commercial Chicken Carcasses in Southern Brazil

Escherichia coli strains designated as avian pathogenic E. coli (APEC) are responsible for avian colibacillosis, an acute and largely systemic disease that promotes significant economic losses in poultry industry worldwide because of mortality increase, medication costs, and condemnation of carcasses. APEC is a subgroup of extraintestinal pathogenic E. coli pathotype, which includes uropathogenic E. coli, neonatal meningitis E. coli, and septicemic E. coli. We isolated E. coli from commercial chicken carcasses in a Brazilian community and compared by polymerase chain reaction-defined phylogenetic group (A, B1, B2, or D) with APEC strains isolated from sick chickens from different poultry farms. A substantial number of strains assigned to phylogenetic E. coli reference collection group B2, which is known to harbor potent extraintestinal human and animal E. coli pathogens, were identified as APEC (26.0%) in both commercial chicken carcasses and retail poultry meat (retail poultry E. coli [RPEC]) (21.25%). The majority of RPEC were classified as group A (35%), whereas the majority of APEC were groups B1 (30.8) and A (27.6%). APEC and RPEC presented the genes pentaplex, iutA, hly, iron, ompT, and iss, but with different virulence profiles. The similarity between APEC and RPEC indicates RPEC as potentially pathogenic strains and supports a possible zoonotic risk for humans.

Typing of Campylobacter jejuni Isolates from Dogs by Use of Multilocus Sequence Typing and Pulsed-Field Gel Electrophoresis

Campylobacter is a major cause of human gastroenteritis worldwide. Risk of Campylobacter infection in humans has been associated with many sources, including dogs. This study aimed to investigate whether C. jejuni carried by dogs could potentially be a zoonotic risk for humans and if there were common sources of C. jejuni infection for both humans and dogs. Multilocus sequence typing (MLST) together with macrorestriction analysis of genomic DNA using SmaI and pulsed-field gel electrophoresis (PFGE) were both used to analyze 33 C. jejuni isolates obtained from various dog populations, including those visiting veterinary practices and from different types of kennels. MLST data suggested that there was a large amount of genetic diversity between dog isolates and that the majority of sequence types found in isolates from these dogs were the same as those found in isolates from humans. The main exception was ST-2772, which was isolated from four samples and could not be assigned to a clonal complex. The most commonly identified clonal complex was ST-45 (11 isolates), followed by ST-21 (4 isolates), ST-508 (4 isolates), and ST-403 (3 isolates). The profiles obtained by macrorestriction PFGE were largely in concordance with the MLST results, with a similar amount of genetic diversity found. The diversity of sequence types found within dogs suggests they are exposed to various sources of C. jejuni infection. The similarity of these sequence types to C. jejuni isolates from humans suggests there may be common sources of infection for both dogs and humans. Although only a small number of household dogs may carry C. jejuni, infected dogs should still be considered a potential zoonotic risk to humans, particularly if the dogs originate from kennelled or hunt kennel dog populations, where the prevalence may be higher.

Occurrence of Escherichia coli in Wildlife from Different Habitats of Sarawak, Malaysia

This study was carried out to assess the occurrence of Escherichia coli (E. coli) in the bats, birds and rodents asrepresentative of wildlife from different habitats in Sibu and Kapit, Sarawak, Malaysia. A total of 682 swabsamples were collected from wildlife hosts and screened for the bacteria E. coli and E. coli O157:H7 usingstandard microbiological methods and molecular techniques. The overall occurrence rates of E. coli among thesehosts were 14%, 17% and 54% for bats, birds and rodents, respectively. The occurrence of E. coli was thehighest in rodents regardless of the habitats. Isolated E. coli were then screened for E. coli O157:H7 by using amultiplex PCR with four primer pairs targeting for Shiga toxin producing genes (slt-I and slt-II), and the genesinvolved in biosynthesis of O157 antigen (rfbE) and H7 antigen (fliCH7 ). slt-I, slt-II and rfbE genes were notdetected in any of the E. coli isolates. However, the gene encoding for H7 antigen was detected in 23 E. coliisolates. This indicated that E. coli O157:H7 strain was not detected in the wildlife studied. Absence of E. coliO157:H7 in the wildlife studied indicated these wild animals do not serve as an important reservoir of E. coliO157:H7. However, precautions have to be taken as other group of pathogenic E. coli may pose a zoonotic riskfor humans and other animals.