Poultry and poultry-derived products such as meat and eggs are among the main sources of non-typhoidal Salmonella (NTS) transmission to the human. Therefore, we performed a systematic review and used random-effects meta-analyses to 1) estimate the prevalence of NTS in poultry samples from birds, products and subproducts, and environmental samples, 2) examine the diversity and frequency of their serovars, and 3) estimate the prevalence and profiles of antimicrobial resistance (AMR) in NTS isolates reported in studies from the Americas. We included 157 studies from 15 countries comprising 261,408 poultry samples and estimated an overall pooled prevalence of 17.9% (95% CI: 10.8–26.3) in birds, 21.8% (17.7–26.1) in products and subproducts, and 29.5% (24.2–35.1) in environmental samples. At the national level, the prevalence of NTS was heterogenous across countries with the highest values in Mexico, the USA, and Canada. In total, 131 serovars were identified from 13,388 isolates, Heidelberg, Kentucky, Enteritidis, and Typhimurium were the most prevalent in the overall top 10 ranking (range 6.5–20.8%). At the national level, Enteritidis and Typhimurium were identified in most of the countries, though with national differences in their ranks. The prevalence of AMR increased from 24.1% for 1 antibiotic, to 36.2% for 2-3 antibiotics, and 49.6% for ≥ 4 antibiotics. Kentucky, Heidelberg, Typhimurium, and Enteritidis were the serovars with the highest prevalence of AMR and tetracycline, ampicillin, streptomycin, ceftiofur, and amoxicillin-clavulanic acid were the top five antibiotics to which NTS isolates were resistant. In conclusion, NTS was distributed through the avian production chain with high and heterogenous values of prevalence in poultry samples. Besides, there were distinctive patterns of serovars distribution across countries and an alarming prevalence of AMR among zoonotic serovars.
Atypical porcine pestivirus (APPV) belongs to the genus Pestivirus within the family Flaviviridae. Recently, APPV has been identified as the causative agent of congenital tremor (CT) type AII. The disease is a neurological disorder that affects newborn piglets and is characterized by mostly generalized trembling of the animals and often splay legs. CT is well known worldwide, and the virus seems to be highly prevalent in major swine producing areas. However, little is known about the epidemiology of the infection, the transmission and spread of the virus between herds. Here, we show the high prevalence of APPV in processing fluid samples collected from Hungarian pig herds which led us to investigate the cellular targets of the virus in the testicles of newborn piglets affected by CT. By the development of an RNA in situ hybridization assay and the use of immunohistochemistry on consecutive slides, we identified the target cells of APPV in the testicle: interstitial Leydig cells, peritubular myoid cells and endothelial cells of medium-sized arteries. Previous studies have shown that APPV can be found in the semen of sexually mature boars suggesting the role of infected boars and their semen in the transmission of the virus similar to many other members of the Flaviviridae family. As in our case, the virus has not been identified in cells beyond the blood-testis barrier, further studies on infected adult boars’ testicles are needed to analyze the possible changes in the cell tropism that enable the virus to be excreted by the semen.
The SARS-CoV-2 virus was detected for the first time in December 2019 in Wuhan, China. Currently, this virus has spread around the world, and new variants have emerged. This new pandemic virus provoked the rapid development of diagnostic tools, therapies and vaccines to control this new disease called COVID-19. Antibody detection by ELISA has been broadly used to recognize the number of persons infected with this virus or to evaluate the response of vaccinated individuals. As the pandemic spread, new questions arose, such as the prevalence of antibodies after natural infection and the response induced by the different vaccines. In Mexico, as in other countries, mRNA and viral-vectored vaccines have been widely used among the population. In this work, we developed an indirect ELISA test to evaluate S1 antibodies in convalescent and vaccinated individuals. By using this test, we showed that IgG antibodies against the S1 protein of SARS-CoV-2 were detected up to 42 weeks after the onset of the symptoms, in contrast to IgA and IgM, which decreased 14 weeks after the onset of symptoms. The evaluation of the antibody response in individuals vaccinated with Pfizer-BioNTech and CanSinoBio vaccines showed no differences two weeks after vaccination. However, after completing the two doses of Pfizer-BioNTech and the one dose of CanSinoBio, a significantly higher response of IgG antibodies was observed in persons vaccinated with Pfizer-BioNTech than in those vaccinated with CanSinoBio. In conclusion, these results confirm that after natural infection with SARS-CoV-2, it is possible to detect antibodies for up to ten months. Additionally, our results showed that one dose of the CanSinoBio vaccine induces a lower response of IgG antibodies than that induced by the complete scheme of the Pfizer-BioNTech vaccine.
The recent COVID-19 pandemic has demonstrated again the global threat posed by emerging zoonotic coronaviruses. During the past two decades alone, humans have experienced the emergence of several coronaviruses, such as SARS-CoV in 2003, MERS-CoV in 2012, and SARS-CoV-2 in 2019. To date, MERS-CoV has been detected in 27 countries, with a case fatality ratio of approximately 34.5 %. Similar to other coronaviruses, MERS-CoV presumably originated from bats; however, the main reservoir and primary source of human infections are dromedary camels. Other species within the Camelidae family, such as Bactrian camels, alpacas, and llamas, seem to be susceptible to the infection as well, although to a lesser extent. In contrast, susceptibility studies on sheep, goats, cattle, pigs, chickens, and horses obtained divergent results. In the present study, we tested nasal swabs and/or sera from 55 sheep, 45 goats, and 52 cattle, collected at the largest livestock market in the United Arab Emirates, where dromedaries are also traded, for the presence of MERS-CoV nucleic acid by RT-qPCR, and for specific antibodies by immunofluorescence assay (IFA). All sera were negative for MERS-CoV-reactive antibodies, but the nasal swab of one sheep (1.8 %) was positive for MERS-CoV nucleic acid. Next generation sequencing (NGS) of the complete N gene of the sheep-derived MERS-CoV revealed >99 % nucleotide identity to MERS-CoV sequences of five dromedaries in nearby pens and to three reference sequences. The NGS sequence of the sheep-derived MERS-CoV was confirmed by conventional RT-PCR of a part of the N gene and subsequent Sanger sequencing. All MERS-CoV sequences clustered within clade B, lineage 5. In conclusion, our study shows that non-camelid livestock, such as sheep, goats, and cattle do not play a major role in MERS-CoV epidemiology. The one sheep that tested positive most likely reflects an accidental viral spillover event from infected dromedaries in nearby pens.
Worldwide, Mycoplasma gallisepticum (MG) and M. synoviae (MS) are the main agents responsible for chronic respiratory disease in poultry. Therefore, we conducted a systematic review and meta-analysis to estimate their occurrence. We searched electronic databases to find peer-reviewed publications reporting the molecular detection of MG and MS in poultry and used meta-analysis to estimate their pooled occurrence (combined flock and individual), aggregating results at the regional and national levels. We performed a subgroup meta-analysis for subpopulations (broilers, layers, breeders, and diverse poultry including turkeys, ducks, and ostriches) and used meta-regression with categorical modifiers. We retrieved 2,294 publications from six electronic databases and included 85 publications from 33 countries that reported 62 studies with 22,162 samples for MG and 48 studies with 26,413 samples for MS. The pooled occurrence was 38.4% (95% CI: 23.5-54.5) for MS and 27.0% (20.4-34.2) for MG. Among regions, Europe and Central Asia had the lowest occurrence for both pathogens, while MG and MS were highly prevalent in South Asia and sub-Saharan Africa, respectively. MG occurrence was higher in Algeria, Saudi Arabia, and Sudan, whereas China, Egypt, and Ethiopia reported a higher occurrence of MS. MS and MG were more prevalent in the breeders and layers (62.6% and 31.2%, respectively) than in diverse poultry. The year of publication, the sample size, and the level of ambient air pollution (measured indirectly by PM2.5) were associated with the occurrence of both mycoplasmas. Our study revealed a high and heterogeneous occurrence of MG and MS and justifies the need for an early detection and improved control measures to reduce the spread of these pathogens.
The current pandemic caused by a novel coronavirus named as SARS-CoV2 has underlined the importance of emerging diseases of zoonotic importance. Along with human beings, several species of wild and pet animals have been demonstrated to be infected by SARS-CoV2, both naturally and experimentally. Additionally, with constant emergence of new variants, the species susceptibility might further change, warranting intensification of screening efforts. India is a vast and second most populated country, with a habitat of a very diverse range of animal species. In this study we are reporting infection of SARS-CoV2 in captive Asiatic lions. Detailed characterization revealed involvement of delta mutant (Pango lineage B.1.617.2) of SARS-CoV2 at two different locations. Interestingly, no other feline species enclosed in the zoo/park was found infected. The epidemiological and molecular analysis in this study will contribute to the understanding of SARS-CoV2 emerging mutants in wild and domesticated animals.
The exact origin of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and source of introduction into humans has not been established yet, though it might be originated from animals. Therefore, we conducted a literature review to understand the putative reservoirs, transmission dynamics, and susceptibility patterns of SARS-CoV-2 in animals. Rhinolophu s bats are presumed to be natural progenitors of SARS-CoV-2 related viruses. Initially pangolin was thought to be the source of spillover to human, but they might get infected from human or other animal species. So, the virus spillover pathways to humans remain unknown. Human-to-animal transmission has been testified in pet, farmed, zoo and free-ranging wild animals. Infected animals can transmit the virus to other animals in natural settings like, mink-to-mink, and mink-to-cat transmission. Animal-to-human transmission is not a persistent pathway, while mink-to-human transmission continues to be illuminated. Multiple companion and captive wild animals were infected by emerging alpha variant of concern (B.1.1.7 lineage) whereas Asiatic lions were infected by delta variant, (B.1.617.2). To date, multiple animal species- cat, ferrets, non-human primates, hamsters, and bats, showed high susceptibility to SARS-CoV-2 in experimental condition, while swine, poultry, cattle showed no susceptibility. The founding of SARS-CoV-2 in wild animal reservoirs can confronts the control of the virus in humans and might carry a risk to the welfare and conservation of wildlife as well. We suggest vaccinating pet, and captive animals to stop spillover and spillback events. We recommend sustainable one health surveillance at animal-human-environmental interface to detect and prevent future epidemics and pandemics by Disease X.
Brucellosis is an endemic disease in many developing countries and ranked by the World Health Organization among the top seven “neglected zoonoses”. Although a Palestinian brucellosis control program was launched in 1998, the disease reemerged after 2012. Interestingly, a similar reemerging pattern was reported in the neighboring Israeli regions. The aim of this work was to characterize the reemerging strains and delineate their genetic relatedness. During 2015-2017, blood samples from 1324 suspected patients were analyzed using two serological tests. Seropositive samples were cultured, and their DNAs were analyzed by different genetic markers to determine the involved Brucella species and rule out any possible involvement of the Rev.1 vaccine strain. The rpoB gene was sequenced from 9 isolates to screen for rifampicin resistance mutations. Multi Locus VNTR Analysis (MLVA-16) was used for genotyping the isolates. The molecular analysis showed that all isolates were B. melitensis strains unrelated to the Rev.1 vaccine. The rpoB gene sequences showed four single nucleotide variations (SNVs) not associated with rifampicin resistance. MLVA-16 analysis clustered the isolates into 22 unique genotypes that belong to the East Mediterranean lineage. Altogether, our findings show that the reemergence of brucellosis was due to B. melitensis strains of local origin, the Palestinian and Israeli control programs’ weaknesses could be a major factor behind the reemergence of the disease. However, other socioeconomic and environmental factors must be investigated. Moreover, strengthening brucellosis control programs and enhancing cooperation between all stakeholders is essential to ensure long-term program outcomes to fight brucellosis.
Classical swine fever (CSF) is caused by classical swine fever virus (CSFV) and has led to huge ecnomic losses for the pig industry worldwide. Although vaccination and other control measures have been carried out, it is essential to establish a rapid and valid method for CSF vaccination monitoring and clinical diagnosis. CSFV E2 protein has been well-known as a major antigen for antibody detection. It is significant to improve affinity between E2 protein and CSFV antibody for a better performance of detection method. In this study, a recombinant E2 extracellular protein (aa 1-331), which has a native homodimer conformation and has a high affinity with anti-CSFV-E2 monoclonal antibody WH303, was expressed using Bac-to-Bac baculovirus expression system. A novel immunochromatographic test strip based on the recombinant CSFV E2 protein was developed for CSFV antibody detection. The sensitivity of this strip for detecting CSFV standard positive serum was 1:102400, 4 times higher than that of the previously developed CnC2 test strip. No cross reaction with antibodies of other swine viruses was observed. The detection of clinical swine serum samples (n=138) demonstrated that the agreements of this E2 test strip with three commercial ELISA kits were 88.40% (122/138), 86.23% (119/138), and 96.38% (133/138), respectively. Our data indicated that a novel E2 test strip with higher sensitivity has been developed and can be applied for clinical sample detections, providing a new powerful and simple approach for CSFV antibody monitoring.
Leptospirosis is a zoonotic neglected disease of worldwide public health concern. Leptospira species can infect a wide range of wild and domestic mammals and can lead to a spectrum of disease, including severe and fatal forms. Herein, we report for the first time a fatal Leptospira interrogans infection in a free-ranging nonhuman primate (NHP), a black-tufted marmoset. Icterus, pulmonary hemorrhage, interstitial nephritis and hepatocellular dissociation were the main findings raising the suspicion of leptospirosis. Diagnostic confirmation was based on specific immunohistochemical and PCR assays for Leptospira species. Immunolocalization of leptospiral antigens and identification of pathogenic species ( L. interrogans species) were important for better understanding the pathogenesis of disease. One Health related implications of free-ranging NHPs in anthropized areas and transmission dynamics of human and animal leptospirosis are discussed.
Rabbit Haemorrhagic Disease (RHD) is a significant viral disease affecting lagomorphs. The first documented cases of RHD in Singapore occurred in adult pet European rabbits in September 2020. Singapore subsequently declared the outbreak resolved in December 2020. Epidemiological investigations ruled out introductions via importation of infected rabbits and contaminated feed. The source could not be definitively determined. However, the findings suggest that the incident involved both inter- and intra-household transmission and veterinary clinic-household transmission. This incident demonstrated the importance of sustained application of biosecurity measures, epidemiological investigations, and control, including active case finding, expedient vaccine dissemination, and risk communications. It shows that Singapore, an urbanised city-state, without a significant lagomorph population, could still encounter emerging diseases such as rabbit haemorrhagic disease. Given its social impact on rabbit owners, the National Parks Board Singapore and the private veterinarians worked together to communicate and urge the adoption of biosecurity measures and assuage the concerns of rabbit owners.
This study aimed to compare the infection dynamics of three genotype II African swine fever viruses (ASFV) circulating in Europe. Eighteen domestic pigs divided into three groups were infected intramuscularly or by direct contact with two haemadsorbent ASFVs (HAD) from Poland (Pol16/DP/ OUT21) and Estonia (Est16/WB/Viru8), and with the Latvian non-HAD ASFV (Lv17/WB/Rie1). Parameters such as symptoms, pathogenicity, and distribution of the virus in tissues, humoral immune response, and dissemination of the virus by blood, oropharyngeal and rectal routes were investigated. The Polish ASFV caused a case of rapidly developing fatal acute disease, while the Estonian ASFV caused acute to subacute infections in the presence of surviving animals. In contrast, animals infected with the ASFV from Latvia developed a more subtle, mild, or even subclinical disease. Oral excretion was sporadic or even absent in the attenuated group, whereas in animals that developed an acute or subacute form of ASF, oral excretion began at the same time as in the blood, or even 3 days earlier, and persisted up to 22 days. Regardless of virulence, blood was the main route of transmission of ASFV and infectious virus was isolated from persistently infected animals for at least 19 days in the attenuated group and up to 44 days in the group of moderate virulence. Rectal excretion was limited to the acute phase of infection. In terms of diagnostics, the ASFV genome was detected in contact pigs from oropharyngeal samples earlier than in blood, independently of virulence and, together with blood, both samples could cover a longer range to detect ASFV infection. The results presented here provide quantitative data on the spread and excretion of ASFV strains of different virulence among domestic pigs that can help to better focus surveillance activities and thus increase the ability to detect ASF introductions earlier.
Bacteriophage is considered an alternative to antibiotics and environmentally friendly approach to tackle antimicrobial resistance (AMR) in aquaculture. Here, we reported isolation, morphology and genomic characterizations of a newly isolated lytic bacteriophage, designated pAh6.2TG. Host range and stability of pAh6.2TG in different environmental conditions, and protective efficacy against a pathogenic multidrug-resistant (MDR) Aeromonas hydrophila in Nile tilapia were subsequently evaluated. The results showed that pAh6.2TG is a member of the family Myoviridae which has genome size of 51,780 bp, encoding 65 putative open reading frames (ORFs), and is most closely related to Aeromonas phage PVN02 (99.33% nucleotide identity). The pAh6.2TG was highly specific to A. hydrophila and infected 83.3% tested strains of MDR A. hydrophila (10 out of 12) with relative stability at pH 7 9, temperature 0 40 °C and salinity 0 40 ppt. In experimental challenge, pAh6.2TG treatments significantly improved survivability of Nile tilapia exposed to a lethal dose of the pathogenic MDR A. hydrophila, with relative percent survival (RPS) of 73.3% and 50% for phage multiplicity of infection (MOI) 1.0 and 0.1, respectively. Significant reduction of bacterial counts in rearing water at 3 h (6.7 ± 0.5 to 18.1 ± 6.98 folds) and in fish liver at 48 h post-treatment (2.7 ± 0.24 to 34.08 ± 26.4 folds) was observed in phage treatment groups while opposite pattern for bacterial counts was observed in untreated control. Interestingly, the surviving fish provoked specific antibody (IgM) against the challenged A. hydrophila. These results might explain the higher survival in phage treatment groups. In summary, the findings suggested that the lytic bacteriophage pAh6.2TG is an effective alternative to antibiotics to control MDR A. hydrophila in tilapia and possibly other freshwater fish.
This systematic review and meta-analysis aimed to recalculate the efficacy of these two vaccine strains, and to discuss the main variables associated with controlled trials to evaluate bovine brucellosis vaccines efficacy. The most used vaccine strain was S19, at the dose of 10 10 colony forming units (CFU), followed by the vaccine strain RB51 at 10 10 CFU. The most used challenge strain was B. abortus 2308, at the dose of 10 7 CFU by intraconjunctival route. For the meta-analysis, trials were grouped according to the vaccine strain and dose to recalculate protection against abortion (four groups) or infection (five groups), using pooled risk ratio (RR) and vaccine efficacy (VE). For protection against abortion (n = 15 trials), S19 vaccine at 10 9 CFU exhibited the highest protection rate (RR = 0.25, 95% CI: 0.12 to 0.52; VE = 75.09%, 95% CI: 48.08 – 88.05), followed by RB51 10 10 (RR = 0.31, 95% CI: 0.16 to 0.61; VE = 69.25%, 95% CI: 39.48 – 84.38). For protection against infection (n = 23 trials), only two subgroups exhibited significant protection: S19 at 10 9 CFU (RR = 0.28, 95% CI: 0.14 to 0.55; VE = 72.03%, 95% CI: 57.70 – 81.50) and RB51 at 10 10 CFU dose (RR = 0.43, 95% CI: 0.22 to 0.84; VE = 57.05%, 95% CI: 30.90 – 73.30). In conclusion, our results suggest that the dose of 10 9 CFU for S19 and 10 10 CFU for RB51 are the most suitable for the prevention of abortion and infection caused by B. abortus.
Peste des petits ruminants (PPR) is a viral transboundary disease of small ruminants that causes significant damage to agriculture. This disease has not been previously registered in the Republic of Kazakhstan (RK). This paper presents an assessment of the susceptibility of the RK’s territory to the spread of the disease in the event of its importation from infected countries. The Generalized Linear Negative Binomial regression model that was trained on the PPR outbreaks in China was used to rank municipal districts in the RK in terms of PPR spread risk. The outbreaks count per administrative district was used as a risk indicator, while a number of socio-economic, landscape and climatic factors were considered as explanatory variables. Summary road length, altitude, the density of small ruminants, the maximum green vegetation fraction, cattle density and the Engel coefficient were the most significant factors. The model demonstrated a good performance in training data (R 2 = 0.69) and was transferred to the RK, suggesting a significantly lower susceptibility of this country to the spread of PPR. Hot Spot analysis identified three clusters of districts at the highest risk, located in the western, eastern and southern parts of Kazakhstan. As part of the study, a countrywide survey was conducted to collect data on the distribution of livestock populations, which resulted in the compilation of a complete geo-database of small ruminant holdings in the RK. The research results may be used to formulate a national strategy for preventing the importation and spread of PPR in Kazakhstan through targeted monitoring in high-risk areas.
Marek’s disease (MD) is a re-emerging viral disease of chicken and a serious economic threat to poultry industry worldwide. Continuous surveillance with molecular investigation is mandatory to monitor the emergence of virulent MDV strains and to devise any appropriate vaccination strategy and implement bio-security programs. In the present study, we investigated the cases of MD outbreaks in vaccinated poultry flocks. The MD outbreak was confirmed through necropsy (majorily visceral tumors), histopathology and viral gene specific PCR. The pathotypes of the field MDV strains were assessed by molecular analysis of three oncogenes -Meq, pp38 and vIL-8. The Meq sequence of the field strains analyzed in this study lacked the 59 aa unique to mild strains indicating that they are virulent strains. Mutation at position 71 and presence of five proline rich repeats in the transactivation domain, both associated with virulence were observed in these strains, however, the signature sequences specific to very virulent plus strains were absent. Phylogenetic analysis of Meq gene sequences revealed clustering of the field strains with North Indian strains and with a very virulent plus ATE 2539 strain from Hungary. Analyses of pp38 protein at positions 107 and 109 and vIL-8 protein at positions 4 and 31 showed signatures of virulence. Sequence and phylogenetic analysis of oncogenes from field MDVs from vaccinated flock indicated these strains possessing molecular features of very virulent strains. Our data shows here that Meq, vIL-8 and pp38 genes can be used as markers for molecular analysis to decipher the pathotype of MDV strains. Our present study suggests evolution of virulent MDV induced by vaccination.
We report a COVID-19 case with unprecedented viral complexity. In the first severe episode, two different SARS-CoV-2 strains (superinfection) were identified within a week. Three months after discharge, patient was readmitted and was infected in a nosocomial outbreak with a different strain, suffering a second milder COVID-19 episode.
Bovine leptospirosis is a bacterial disease that affects cattle herds, causing economic losses due to reproductive problems, which require expensive treatments. The main source of transmission for cattle is still uncertain, but it has been described that rodents and bats can play an important role in the transmission cycle by being maintenance hosts for the pathogenic species of the bacterium and spreading it through urine. In this study, we characterize possible risk areas for bovine leptospirosis exposure in the state of Veracruz, Mexico, based on the geographical distribution of flying (bats) and terrestrial (rodents and opossums) wild hosts of Leptospira sp. reported in Mexico in addition with climatic, geographic, soil characteristics, land use and human activities variables (environmental variables). We used a generalized linear regression model (GLM) to understand the association between the frequency of anti- Leptospira sp. antibodies (a proxy of exposure to) in cattle herds exposed to Leptospira, the favorability of wild hosts of Leptospira as well as the environmental variables. The parameterized model explains 12.3% of the variance. The frequency of anti- Leptospira sp. antibodies exposoure in cattle herds was associated with elevation, geographic longitude, pH of the soil surface and environmental favorability for the presence of rodents, opossums, and bats. The variation in exposure is mainly explained by a longitudinal gradient (6.4% of the variance) and the favorability-based indices for wild hosts (9.6 % of the variance). Describing the possible risks for exposure to Leptospira in an important and neglected livestock geographical region, we provide valuable information to the selection of areas for diagnosis and prevention of this relevant disease.