Serosurveillance for Severe Acute Respiratory Syndrome Coronavirus 2 Antibody in Feral Swine and White-Tailed Deer in Texas.

Background: Serological evidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has been reported in white-tailed deer (WTD) in the United States and Canada. Even though WTD are susceptible to SARS-CoV-2 infection, there is no evidence of infection by this virus in other mammalian species that might interact with WTD in nature. Similar to WTD, feral swine are widely distributed and generally occupy the same range as WTD in Texas. The objective of this study was to determine the prevalence of SARS-CoV-2 neutralizing antibody in WTD during 2020 and 2021 and determine the prevalence of SARS-CoV-2 neutralizing antibody in feral swine during 2018 (prepandemic period) and from March 2020 to February 2021 (pandemic period) in Travis County, Texas. Materials and Methods: Sera samples were collected from hunter-killed WTD and feral swine during the prepandemic and pandemic period and tested for SARS-CoV-2 antibody by a plaque reduction neutralization assay in Vero cells. Results: SARS-CoV-2 antibody was not detected in any of the 166 feral swine sera samples, including 24 samples collected during the prepandemic and 142 samples collected during the pandemic period. Furthermore, SARS-CoV-2 antibody was not detected in the 115 WTD samples collected during late 2020, but antibody was detected in WTD in early 2021. Conclusions: The results indicated that SARS-CoV-2 infection of WTD occurred during early 2021 in Travis County, Texas, but serological evidence of SARS-CoV-2 infection was not detected in the feral swine samples collected from the same locality and during the same time period of the collection of WTD samples.

Clinical and epidemiological characteristics of probable cases of congenital Zika syndrome and dengue antibody levels, Tuxtla Gutierrez, Chiapas, Mexico

Introduction: We previously found that the occurrence of congenital Zika syndrome was under-reported in Mexico. It was postulated that high dengue virus antibody levels found at the population-level in endemic countries might have contributed to the occurrence of the regional pandemic of Zika disease. A case series of suspected cases of congenital Zika syndrome in a maternity hospital in Tuxtla Gutierrez, Chiapas, Mexico was assembled to assess why they were not reported and to explore the hypothesis of dengue virus antibody-dependent enhancement of Zika disease. Methods: We used a quantitative approach to describe clinical and imaging records and used data from interviews of a total of 13 suspected cases of congenital Zika syndrome. We also quantitated dengue 1 and 2 antibodies using an 80% plaque reduction neutralization test of sera specimens obtained from the mothers of these 13 cases and compared them to those of a group of mothers who delivered normal newborns in the same hospital. Results: Only one of the suspected cases was laboratory-confirmed because appropriate specimens were not collected from the newborns as required by the case definition. We found 1) microcephaly, 2) hypoplasia/hypogeneses, thinning or absence of brain structures, 3) multiple birth defects, 4) calcifications, and cysts, 5) meningocele/encephalocele, and 6) hydrocephalus in 100 %, 76.9 %, 38.5 %, 38.5 %, 30.8 %, and 23.1 %, respectively of the case series. The cases clustered geographically, and 77 % occurred between May 2016 to March 2017 and recalled or were told by a doctor they had Zika fever. There was a four-fold increased risk of congenital Zika syndrome among those with dengue 1 antibody as compared to those with dengue 2 antibodies (odds ratio = 3.6; 95 % confidence interval: 0.7, 20.5), reaching only borderline statistical significance. Conclusions: We found in the largest maternal facility of the capital of the State of Chiapas, in Mexico, that only 7.7 % of suspected cases were confirmed, and that the rather complex requirement of cerebrospinal fluid specimens or serological specimens of newborns for suspected cases of congenital Zika syndrome used during the pandemic resulted in low sensitivity of the surveillance system. The finding of higher levels of dengue 1 than dengue 2 antibodies in cases than the referent population, requires further evaluation and may suggest a role for dengue antibody-dependent response in Zika disease.

Introducción: Previamente los autores habían encontrado evidencia de sub-notificación de la ocurrencia del síndrome congénito por Zika en México. Se ha postulado que niveles elevados de anticuerpos contra los virus del dengue a nivel poblacional en los países endémicos hubiese contribuido a la ocurrencia de la pandemia regional de enfermedad por Zika. Ensamblamos una serie de casos sospechosos de síndrome congénito por Zika en un hospital de maternidad en Tuxtla Gutiérrez, Chiapas, México, para evaluar por qué no fueron notificados y explorar la hipótesis de enfermedad por Zika incrementada por anticuerpos anti-dengue. Métodos: Utilizamos un enfoque cuantitativo para describir 13 casos sospechosos de síndrome congénito por revisamos registros clínicos e imágenes, entrevistas. También cuantificamos los niveles de anticuerpos para los virus dengue 1 y 2 en suero de las madres de los casos comparados con los de mujeres que tuvieron recién nacidos normales en el mismo hospital. Resultados: Solamente uno de los 12 casos sospechosos fue confirmado por laboratorio, porque en los demás no se recolectaron especímenes adecuados de los neonatos como lo requería la definición de casos. Encontramos 1) microcefalia, 2) hipoplasia y adelgazamiento de las estructuras cerebrales, 3) malformaciones múltiples, 4) calcificaciones o quistes, 5) meningocele/encefalocele, y 6) hidrocefalia en: 100 %, 76.9 %, 38.5 %, 38.5 %, 30.8 %, y 23.1 %, en ese orden entre los casos sospechosos. Los casos se aglutinaron geográficamente y 77 % ocurrieron entre Mayo del 2016 y Marzo del 2017, y sus madres recordaban que tuvieron o que un profesional de la salud les dijo que tuvieron fiebre por Zika. Encontramos un incremento de casi 4 veces en el riesgo de síndrome congénito por Zika para aquellos con altos niveles de anticuerpos anti-dengue 1 comparado con anticuerpos anti-dengue 2 (cociente de suertes = 3.6; intervalo de confianza del 95 %: 0.7, 20.5), alcanzando solamente una significancia estadística limítrofe. Conclusiones: Encontramos en el establecimiento de atención a la maternidad más grande en la capital de Chiapas, México, que solamente 7.7 % de los casos sospechosos de síndrome congénito por Zika fueron confirmados y que los relativamente complejos requerimientos de la definición de casos de muestras serológicas o de líquido cefalorraquídeo resultó en una baja sensibilidad del sistema de vigilancia. El hallazgo de niveles más altos de anticuerpos a dengue 1 que dengue 2 requiere más evaluación y pudiera sugerir un papel de la respuesta dependiente de anticuerpos al dengue en Zika.

Estimation of the Minimal Rift Valley Fever Virus Protective Neutralizing Antibody Titer in Human Volunteers Immunized with MP-12 Vaccine Based on Protection in a Mouse Model of Disease.

The Rift Valley fever virus (RVFV) MP-12 vaccine is a promising human and veterinary vaccine. Although the vaccine elicited neutralizing antibody (nAb) in human volunteers, the minimal antibody titer that is needed to afford protection is unknown. Therefore, this study was conducted to determine the minimal nAb titer elicited by the RVFV MP-12 vaccine in human volunteers that protected mice against lethal RVFV challenge as a surrogate assessment of the protective efficacy of the vaccine. Among volunteers who were vaccinated with the MP-12 vaccine during a phase II trial, sera with antibody titers of 1:20 collected 5 years post-vaccination (PV), 1:40 titer collected 2 years PV, and 1:80 titer collected 1 year PV was passively transferred to groups of BALB/c mice. Blood samples were obtained 1 day after passive transfer to determine the RVFV neutralizing nAb titer before challenge with pathogenic RVFV (strain ZH501). Our results indicated that 1 day after passive transfer of the immune sera, an approximate 4-fold reduction in circulating nAb titers was detected in the mice. The presence of RVFV nAb titers in the range of 1:5 to 1:20 were generally protective (75-100% survival). These results suggested that circulating titers of 1:5 or higher offer a high degree of protection by MP-12-elicited antibody in human volunteers. Also, the findings highlighted the value of using the BALB/c mouse RVFV challenge model as a surrogate for evaluating the protective nAb responses elicited by MP-12 and possible use for evaluating the efficacy of other RVFV vaccine candidates.

SARS-CoV-2 Neutralizing Antibodies in White-Tailed Deer from Texas.

Serological evidence of SARS-CoV-2 infection among white-tailed deer has been reported from Illinois, Michigan, Pennsylvania, and New York. This study was conducted to determine whether deer in Texas also had evidence of SARS-CoV-2 infection. Archived sera samples collected from deer in Travis County, Texas, during 2018, before and during the pandemic in 2021 were tested for neutralizing antibody to this virus by a standard plaque reduction neutralization assay. SARS-CoV-2 antibody was not detected in 40 deer sera samples collected during 2018, but 37% (20/54) samples collected in 2021 were positive for antibody. The seroprevalence rate between males and females differed significantly (p < 0.05) and the highest rate (82%) was detected in the 1.5-year-old animals. These findings extended the geographical range of prior SARS-CoV-2 infection among white-tailed deer in the United States and further confirm that infection was common among this species.

Characterization of a Dengue Virus Serotype 1 Isolated from a Patient in Ciudad Juarez, Mexico.

Dengue (DEN) is the most important human arboviral disease worldwide. Sporadic outbreaks of DEN have been reported since 1980 in urban communities located along the border in southeast Texas and northern Mexico. Other than the Rio Grande Valley region of TX, autochthonous transmission of DENV has not been reported from any other US border communities. As part of a surveillance program for arthropod-borne viruses in Ciudad Juarez, Mexico, during November 2015, a blood sample was obtained from a female patient who experienced an undifferentiated fever and arthralgia. The plasma of the sample was tested for virus in Vero-76 and C6/36 cells. DENV serotype 1 (DENV-1) was isolated in the C6/36 cells, and nucleotide sequencing of the envelope gene and full genome grouped the DENV-1 isolate in the Central America clade. The patient had not traveled outside of Ciudad Juarez, Mexico, thus suggesting DENV-1 infection was acquired in this community.

Serosurvey for dengue virus infection among pregnant women in the West Nile virus enzootic community of El Paso Texas.

All 4 dengue viruses (DENV) cause sporadic outbreaks of human disease in the Rio Grande Valley along the US-Mexico border. In addition, West Nile virus (WNV) is enzootic in most border communities, and is the only arbovirus known to cause human disease in the El Paso, Texas community. In an effort to determine if DENV were also endemic in the El Paso community, a serosurvey was conducted among mothers at the time of delivery of their babies in selected hospitals. Cord-blood plasma samples obtained from mothers were tested for DENV antibody by an enzyme-linked immuno-sorbent assay (ELISA), plaque reduction neutralization test (PRNT) and a multiplex microsphere immunoassay. All DENV antibody positive plasma samples were also tested for WNV antibody by the same assays to consider the possibility that DENV antibody positive samples reflected WNV cross reactive antibody. The results indicated that 0.74% (11/1,472) of the mothers had a previous DENV infection and that 3.3% (48/1,472) had a previous WNV infection. Of these mothers, 0.20% (3/1,472) had antibody to both DENV and WNV as evidence of infection by both viruses. The results indicated that 0.2% (3/1472) of the mothers were positive for antibody to only WNV envelope, thus suggesting an undetermined flavivirus infection. Although 6 of the 11 DENV antibody positive mothers did not have a history of travel to a DENV endemic country, the findings of this survey provided further evidence of local transmission of WNV and suggested the possibility of focal autochthonous transmission of DENV in the El Paso community.

Serological Evidence of West Nile Virus Infection in White-Tailed Deer in Central Texas.

White-tailed deer (WTD) are abundant mammals widely distributed across the United States. As a result, WTD are considered to be excellent sentinels for detecting arboviral activity in certain geographic areas. Evidence of West Nile virus (WNV) antibody in WTD has been reported previously in several states. However, WNV infection in WTD has not been reported from Texas, where the incidence of human West Nile (WN) cases is among the highest in the United States. Therefore, the aim of this study was to determine the prevalence of WNV antibody in WTD in central Texas. Sera samples (n = 644) were collected from deer during the fall and winter in western Travis County, Texas from 2014 to 2018 and tested for WNV immunoglobulin G (IgG) antibody by an indirect enzyme-linked immunosorbent assay (ELISA). ELISA antibody-positive samples were further tested for WNV and St. Louis encephalitis virus (SLEV) antibodies by an 80% plaque-reduction neutralization tests (PRNT80). Overall, 9% (n = 58) and 0.31% (n = 2) of the deer samples had serological evidence of WNV and SLEV infections, respectively. WNV seroprevalence differed significantly by age (p < 0.05), but there was no significant difference between sex. Interestingly, 3.1% (n = 20) of the samples were positive for Flavivirus IgG antibody by ELISA, but negative for SLEV and WNV antibodies, suggesting that other Flaviviruses may be circulating among WTD in Texas. Finally, these results supported WNV infection among WTD and highlight their potential role as sentinels for the detection of WNV in Texas and warrant further studies to determine the role WTD play in the maintenance and transmission of WNV.

Marker-free PLRV resistant potato mediated by Cre-loxP excision and RNAi.

An inverted repeat construct corresponding to a segment of the potato leaf roll virus coat protein gene was created under control of a constitutive promoter and transferred into a transformation vector with a heat inducible Cre-loxP system to excise the nptII antibiotic resistance marker gene. Fifty-eight transgenic events were evaluated for resistance to PLRV by greenhouse inoculations, which lead to the identification of 7 highly resistant events, of which 4 were extremely resistant. This resistance was also highly effective against accumulation in subsequent tuber generations from inoculated plants, which has not been reported before. Northern blot analysis showed correlation of PLRV specific siRNA accumulation with the level of PLRV resistance. Heat mediated excision of the nptII antibiotic resistance gene in PLRV resistant events was highly efficient in one event with full excision in 71 % of treated explants. On the other hand 8 out of 10 analyzed events showed truncated T-DNA insertions lacking one of the two loxP sites as determined by PCR and confirmed by sequencing flanking regions in 2 events, suggesting cryptic LB sites in the non-coding region between the nptII gene and the flanking loxP site. Accordingly, it is proposed to modify the Cre-loxP vector by reducing the 1 kb size of the region between nptII, loxP, and the LB.

Identificación molecular de Pichia guillermondii aislada de aguas ácidas de minas en el Perú y su resistencia a metales pesados / Molecular identification of Pichia guillermondii isolated from mine water acidic of Peru and its resistance to heavy metals

Las aguas ácidas de minas tienen una considerable diversidad de microorganismos eucariontes, entre ellos hongos y protistas; en particular, poco se conoce sobre la diversidad de levaduras en drenajes ácidos de minas peruanas. En el presente estudio se aisló y caracterizó la levadura 1MA9, mediante la amplificación y secuenciación del LSU D1/D2 del gen rRNA 26S. La cepa 1MA9 se identificó molecularmente como Pichia guillermondi, ésta presentó una resistencia alta a Mn2+ (>400 mM), intermedia a iones Zn2+ y Co2+ (400—600 mM), pero fue sensible a iones Cu2+. Este trabajo representa el primer reporte de levaduras en ambientes acuáticos ácidos proveniente de minas peruanas.

Microbe eukaryotes like fungi and protista are common in the drainage of mines. Few information is known on microbial diversity of acid drainages of Peruvian mines. In this work we isolated and characterized the 1M9 yeast. We utilized LSU D1/D2 of the 26S rRNA gene sequence phylogenetic analyses to characterize the diversity the yeast 1MA9 isolated. The strain 1MA9 was closely related to the Pichia guilliermondii. The yeast showed high resistance to Mn2+ (>400 mM), intermediate to ions Zn2+ and Co2+ (400—600 mM), but sensible to ions Cu2+. This work provides the first data on yeasts from an aquatic acid environment of Peruvian mines.