Long-term acute infections during a bovine viral diarrhea virus (BVDV) outbreak in dairy farm from Galicia (NW Spain).

An observational study describes an outbreak of bovine viral diarrhea virus (BVDV) in a dairy herd in Spain. The herd was subjected to a voluntary control program. In a sampling carried out in June 2020, bulk tank milk antibody levels increased compared to the previous sampling. Additionally, serum samples from 4 young heifers also tested positive for antibodies. Since the results were consistent with a recent infection, we proceeded to detect possible persistently infected (PI) animals using antigen ELISA (on serum/ear-notch samples), following the program guidelines. From this moment on, 42 animals tested positive for BVDV antigen, of which 17 were under typical acute infection (AI), 13 were deemed as PI, and eight died early on the farm before having information to determine their status. The remaining 4 showed intriguing test results consistent with a long-term AI since they tested BVDV positive in at least two antigen tests more than 3 weeks apart. Thus, one animal was positive until 80 days of age in serum, and others even for longer periods in ear-notch samples, until they finally tested negative for BVDV. Based on these results, longer follow-up may be necessary in BVDV positive animals to accurately confirm persistent infection.

Q fever screening among pregnant women with pre-term delivery in northern Israel: An observational study.

The relationship between Q fever, caused by Coxiella burnetii, and obstetrical complications is debatable. Since Q fever is endemic in Israel, we aimed to assess its seroprevalence and clinical characteristics in pre-term deliveries. Between 1 August 2017 and 31 December 2019, we conducted serological screening for C. burnetii in pregnant women who presented to Rambam Health Care Campus with pre-term delivery (before 37 weeks of gestation). Anti-C. burnetii antibodies were tested first by enzyme-linked immunosorbent assay for the detection of phase I-IgG, phase II-IgG and phase II-IgM. Positive results were confirmed by indirect immunofluorescence with titre determination. Seropositivity was classified into past, acute and chronic infection. Demographic and clinical data of mothers and neonates were collected and compared between seropositive and seronegative women. Out of 386 pregnant women screened for anti-C. burnetii antibodies, 16 (4.1%) were seropositive, of whom three were diagnosed with past, 12 with acute and one with chronic infection. A higher percentage of seropositive women were immunosuppressed, 2/16 (12.5%) compared with 7/370 (1.9%) in seronegative women, (p = .05). Neonates with small for gestational age were born to 2/16 (12.5%) seropositive women compared with 29/370 (7.8%) to seronegative women, (p = .35). The seroprevalence of Q fever among pregnant women with pre-term birth reached 4% in northern Israel. This high rate in an endemic setting encourages investigating the role of routine screening for Q fever during pregnancy. Special attention should be given to pregnant immunosuppressed women at risk for exposure to Q fever.

[Equine anaplasmosis and equine piroplasmosis in Germany, Austria and Switzerland - previously anecdotal, now relevant?] / Equine Anaplasmose und equine Piroplasmose in Deutschland, Österreich und der Schweiz ­ früher anekdotisch, heute relevant?

INTRODUCTION: Equine granulocytic anaplasmosis (EGA) and equine piroplasmosis (EP) are triggered by tick-borne pathogens - the intracellular bacterium Anaplasma phagocytophilum and the intracellular protozoa Babesia caballi and Theileria equi. These pathogens attack cells in the blood stream and cause similar clinical symptoms and changes in laboratory values. Although the treatment principles are naturally different, similarities in prophylaxis exists due to the transmission route. Tick transmitted pathogens can play a greater role in equine medicine in the future due to various factors, such as the tendency of relevant tick species to spread, but also the increasing import and travel activities of and with pets (both in the context of sporting events and as a leisure activity). While EGA is endemic in Central Europe, EP is a sporadic disease in Switzerland, Austria and Germany. However, EP must be viewed as underdiagnosed, as horses persistently infected with T. equi are also repeatedly detected in Central Europe. These diseases should be considered in horses with a fever and corresponding laboratory changes. Available diagnostic tests are direct pathogen detection by blood smear or PCR, and, indirect antibody detection, which is considered to be highly sensitive and (as a competitive ELISA) also very specific. Acute infections can be detected with PCR, serology is more suitable for chronic infections. A pathogen-free condition after treatment can be demonstrated with decreasing antibody titers in combination with repeated PCR tests. In addition, clinically healthy horses infected with T. equi should be identified by antibody detection and appropriate preventative transmission measures must be initiated. The prophylaxis of tick bites in horses is difficult due to the high exposure, and long-term tick bite prevention can hardly be guaranteed. Monitoring of tick activity and strict measures to prevent the spread of the pathogen within the tick population are therefore of great importance.

INTRODUCTION: L'anaplasmose granulocytaire équine (EGA) et la piroplasmose équine (EP) sont causées par des agents pathogènes transmis par les tiques ­ la bactérie intracellulaire Anaplasma phagocytophilum et les protozoaires intracellulaires Babesia caballi et Theileria equi. Ces agents pathogènes attaquent les cellules sanguines et provoquent des symptômes cliniques similaires et des modifications des valeurs de laboratoire. Bien que les principes de traitement soient naturellement différents, des similitudes dans la prophylaxie existent en raison de la voie de transmission. Les agents pathogènes transmis par les tiques pourraient jouer un rôle plus important en médecine équine à l>avenir en raison de divers facteurs, tels que la tendance des espèces de tiques concernées à se propager, mais aussi l>augmentation des activités d>importation et de voyage d>animaux de compagnie avec eux (à la fois dans le contexte d>événements sportifs et comme activité de loisir). Alors que l>EGA est endémique en Europe centrale, l>EP est une maladie sporadique en Suisse, en Autriche et en Allemagne. Cependant, l'EP doit être considérée comme sous-diagnostiquée, car des chevaux infectés de manière persistante par T. equi ont également été détectés à plusieurs reprises en Europe centrale. Ces maladies doivent être envisagées chez les chevaux présentant de la fièvre et des modifications biologiques correspondantes. Les tests de diagnostic disponibles sont la détection directe des agents pathogènes par frottis sanguin ou par PCR et la détection indirecte des anticorps, qui est considérée comme très sensible et, en tant qu'ELISA compétitif, également très spécifique. Les infections aiguës peuvent être détectées par PCR, la sérologie est plus adaptée aux infections chroniques. Une condition sans agent pathogène après le traitement peut être démontrée avec des titres d'anticorps décroissants en combinaison avec des tests PCR répétés. De plus, les chevaux cliniquement sains infectés par T. equi doivent être identifiés par détection d'anticorps et des mesures appropriées pour prévenir la transmission doivent être initiées. La prophylaxie des morsures de tiques chez les chevaux est difficile en raison de la forte exposition et la prévention des morsures de tiques à long terme peut difficilement être garantie. La surveillance de l'activité des tiques et des mesures strictes pour empêcher la propagation de l'agent pathogène au sein de la population de tiques sont donc d'une grande importance.

Distinct behavior of bovine-associated staphylococci species in their ability to resist phagocytosis and trigger respiratory burst activity by blood and milk polymorphonuclear leukocytes in dairy cows.

Mastitis affects a high proportion of dairy cows and is still one of the greatest challenges faced by the dairy industry. Staphylococcal bacteria remain the most important cause of mastitis worldwide. We investigated how distinct staphylococcal species evade some critical host defense mechanisms, which may dictate the establishment, severity, and persistence of infection and the outcome of possible therapeutic and prevention interventions. Thus, the present study investigated variations among distinct bovine-associated staphylococci in their capability to resist phagocytosis and to trigger respiratory burst activity of blood and milk polymorphonuclear neutrophil leukocytes (PMNL) in dairy cows. To do so, PMNL of 6 primiparous and 6 multiparous dairy cows were used. A collection of 38 non-aureus staphylococci (NAS) and 12 Staphylococcus aureus were included. The phagocytosis and intracellular reactive oxygen species (ROS) production by blood and milk PMNL were analyzed by flow cytometry. Phagocytosis, by both blood and milk PMNL, did not differ between S. aureus and NAS as a group, although within-NAS species differences were observed. Staphylococcus chromogenes (a so-called milk-adapted NAS species) better resisted phagocytosis by blood PMNL than the so-called environmental (i.e., Staphylococcus fleurettii) and opportunistic (i.e., Staphylococcus haemolyticus) NAS species. Otherwise, S. haemolyticus was better phagocytosed by blood PMNL than S. aureus, S. fleurettii, and S. chromogenes. No influence of the origin of the isolates within the staphylococci species in the resistance to phagocytosis by blood and milk PMNL was found. Overall, both S. aureus and NAS did not inhibit intracellular ROS production in blood and milk PMNL. Non-aureus staphylococci induced fewer ROS by milk PMNL than S. aureus, which was not true for blood PMNL, although species-specific differences in the intensity of ROS production were observed. Staphylococcus chromogenes induced more blood PMNL ROS than S. fleurettii and S. haemolyticus, and as much as S. aureus. Conversely, S. chromogenes induced fewer milk PMNL ROS than S. aureus. The origin of the isolates within the staphylococci species did not affect the ROS production by blood and milk PMNL. In conclusion, our study showed differences in staphylococci species in evading phagocytosis and triggering ROS production, which may explain the ability of some staphylococci species (i.e., S. aureus and S. chromogenes) to cause persistent infection and induce inflammation.

Innate Immune Antagonism of Mosquito-Borne Flaviviruses in Humans and Mosquitoes.

Mosquito-borne viruses of the Flavivirus genus (Flaviviridae family) pose an ongoing threat to global public health. For example, dengue, Japanese encephalitis, West Nile, yellow fever, and Zika viruses are transmitted by infected mosquitoes and cause severe and fatal diseases in humans. The means by which mosquito-borne flaviviruses establish persistent infection in mosquitoes and cause disease in humans are complex and depend upon a myriad of virus-host interactions, such as those of the innate immune system, which are the main focus of our review. This review also covers the different strategies utilized by mosquito-borne flaviviruses to antagonize the innate immune response in humans and mosquitoes. Given the lack of antiviral therapeutics for mosquito-borne flaviviruses, improving our understanding of these virus-immune interactions could lead to new antiviral therapies and strategies for developing refractory vectors incapable of transmitting these viruses, and can also provide insights into determinants of viral tropism that influence virus emergence into new species.

Recent advances in cell homeostasis by African swine fever virus-host interactions.

African swine fever (ASF) is an acute hemorrhagic disease caused by the infection of domestic swine and wild boar by the African swine fever virus (ASFV), with a mortality rate close to 90-100%. ASFV has been spreading in the world and poses a severe economic threat to the swine industry. There is no high effective vaccine commercially available or drug for this disease. However, attenuated ASFV isolates may infect pigs by chronic infection, and the infected pigs will not be lethal, which may indicate that pigs can produce protective immunity to resistant ASFV. Immunity acquisition and virus clearances are the central pillars to maintain the host normal cell activities and animal survival dependent on virus-host interactions, which has offered insights into the biology of ASFV. This review is organized around general themes including native immunity, endoplasmic reticulum stress, cell apoptosis, ubiquitination, autophagy regarding the intricate relationship between ASFV protein-host. Elucidating the multifunctional role of ASFV proteins in virus-host interactions can provide more new insights on the initial virus sensing, clearance, and cell homeostasis, and contribute to understanding viral pathogenesis and developing novel antiviral therapeutics.

Simultaneous and Staggered Foot-and-Mouth Disease Virus Coinfection of Cattle.

Foot-and-mouth disease (FMD) field studies have suggested the occurrence of simultaneous infection of individual hosts by multiple virus strains; however, the pathogenesis of foot-and-mouth disease virus (FMDV) coinfections is largely unknown. In the current study, cattle were experimentally exposed to two FMDV strains of different serotypes (O and A). One cohort was simultaneously infected with both viruses, while additional cohorts were initially infected with FMDV A and subsequently superinfected with FMDV O after 21 or 35 days. Coinfections were confirmed during acute infection, with both viruses concurrently detected in blood, lesions, and secretions. Staggered exposures resulted in overlapping infections as convalescent animals with persistent subclinical FMDV infection were superinfected with a heterologous virus. Staggering virus exposure by 21 days conferred clinical protection in six of eight cattle, which were subclinically infected following the heterologous virus exposure. This effect was transient, as all animals superinfected at 35 days post-initial infection developed fulminant FMD. The majority of cattle maintained persistent infection with one of the two viruses while clearing the other. Analysis of viral genomes confirmed interserotypic recombination events within 10 days in the upper respiratory tract of five superinfected animals from which the dominant genomes contained the capsid coding regions of the O virus and nonstructural coding regions of the A virus. In contrast, there were no dominant recombinant genomes detected in samples from simultaneously coinfected cattle. These findings inculpate persistently infected carriers as potential FMDV mixing vessels in which novel strains may rapidly emerge through superinfection and recombination. IMPORTANCE Foot-and-mouth disease (FMD) is a viral infection of livestock of critical socioeconomic importance. Field studies from areas of endemic FMD suggest that animals can be simultaneously infected by more than one distinct variant of FMD virus (FMDV), potentially resulting in emergence of novel viral strains through recombination. However, there has been limited investigation of the mechanisms of in vivo FMDV coinfections under controlled experimental conditions. Our findings confirmed that cattle could be simultaneously infected by two distinct serotypes of FMDV, with different outcomes associated with the timing of exposure to the two different viruses. Additionally, dominant interserotypic recombinant FMDVs were discovered in multiple samples from the upper respiratory tracts of five superinfected animals, emphasizing the potential importance of persistently infected FMDV carriers as sources of novel FMDV strains.

Effect of antibiotic treatment on Mycoplasma hyopneumoniae detection and infectious potential.

Mycoplasma hyopneumoniae (M. hyopneumoniae) causes significant economic losses in the swine industry. Antibiotics with activity against Mycoplasma spp. are employed for disease mitigation and pathogen elimination. However, veterinarians are often challenged with the detection of M. hyopneumoniae by PCR after antibiotic treatment, thus raising the question whether the bacterium is still infectious. The objective of this study was to evaluate the effect of tulathromycin treatment on M. hyopneumoniae detection and infectious potential during the acute and chronic phases of infection. For each infection phase, one age-matched naïve gilt was placed in contact with one M. hyopneumoniae infected gilt that was either treated with tulathromycin, treated and vaccinated, or non-treated, for 14 days. Four replicates per treatment group were performed for each infection phase. A numerical reduction in relative bacterial load was observed in acutely treated gilts compared to non-treated gilts. The rate at which naïve gilts became infected with M. hyopneumoniae was numerically reduced when co-housed with treated, acutely infected gilts compared to those housed with non-treated, infected gilts. During the chronic infection phase, M. hyopneumoniae was detected by PCR in more than 50 % of treated infected gilts and persisted for up to three months post-treatment. Transmission was not detected in all treatment groups however, the possibility that the pathogen was infectious could not be completely ruled out. Further research focused on assessing M. hyopneumoniae detection and viability post-treatment is necessary to guide control and elimination efforts.

In Vitro and In Vivo IFN-γ and IL-10 Measurement in Experimental Brucella abortus Biotype 1 Infection in Sprague-Dawley Rats.

The immune response to Brucella abortus mainly depends on antigen-specific T cell activation, CD4+ and CD8+ T cells, and Brucella-specific humoral response. Protective immune response against Brucella infection has not been performed in the Sprague-Dawley (SD) rat model. We measured bacterial kinetics in addition to in vivo and in vitro interferon gamma (IFN-γ) and interleukin-10 (IL-10) production against crude Brucella protein in the SD rats at different days of postinfection with B. abortus biotype 1 by indirect enzyme-linked immunosorbent assay. Forty SD rats were inoculated intraperitoneally with 0.1 mL sterile injectable pyrogen-free solution containing 1 × 1010 colony-forming units/mL of B. abortus biotype 1 obtained from cattle in Korea. Four rats were used as uninfected control. Serum IFN-γ level at 3 and 7 days postinfection were significantly higher (p > 0.001) compared with the IL-10 level. On the contrary, serum IL-10 levels were observed significantly higher at 21 and 28 days postinfection compared with the serum IFN-γ levels (p < 0.001). The production of IFN-γ by spleen cells was significantly higher at 7 and 14 days postinfection compared with IL-10 (p < 0.001). On the contrary, IL-10 productions were found to be significantly higher at 21, 28, 35, and 42 days postinfection compared with IFN-γ (p < 0.001). The presence of B. abortus in blood was marked till 5 weeks of infection, throughout the experiment in case of spleen, and no bacteria were isolated from the kidney and liver at 6 weeks postinfection. The in vivo and in vitro IFN-γ and IL-10 measurement in our study reported that B. abortus infection in rats primarily educe T helper (Th)1-dominant immune response in acute infection accompanied by Th2-dominant immune response in chronic infection.