Isolation ofBdellovibriosp. from soil samples in Mexico and their potential applications in control of pathogens

In this study, two strains of Bdellovibrio were isolated from soil samples using the culture-dependent technique and two members of the family Enterobacteriaceae (Klebsiella sp. and Salmonella sp.) as prey. The Bdellovibrio strains were bacteriolytic, plaque-forming, and highly motile gram-negative bacteria. We identified and confirmed the Bdellovibrio strains using microscopy, PCR amplification, and sequencing of the 16S rRNA gene. They were observed to be different strains based on hit locus and prey range analyses. Here, the first report on Bdellovibrio strains isolated from soil in Mexico corroborates earlier report indicating that populations of Bdellovibrio found in soil are heterogeneous thereby the need to identify the various strains

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

First record of invasive mosquito aedes albopictus in tabasco and Yucatan, Mexico

The invasive mosquito Aedes albopictus is currently distributed in most of the southern Mexican region. Since the species was first recorded in the state of Tamaulipas, in northeastern Mexico in 1988, it has expanded its distribution throughout the Sierra Madre Oriental and Gulf of Mexico to the Neotropical region of the country. Currently the species occurs in the states of Tamaulipas, Coahuila, Nuevo Leon, Veracruz, Chiapas, Morelos, Quintana Roo, Sinaloa, San Luis Potosi, and Hidalgo. This is the first report of the mosquito in the states of Tabasco and Yucatan and the confirmation of its presence in Quintana Roo state. Aedes albopictus has been incriminated as a secondary vector of diseases such as those caused by dengue, chikungunya, and Zika viruses, which have caused epidemic outbreaks in most tropical and subtropical regions of Mexico; therefore, surveillance for the detection of Ae. albopictus is paramount so that targeted control strategies can be implemented for its control throughout Mexico

Potential of Neem-based Varnish as Adulticide of Aedes aegypti Mosquitoes

Aedes aegypti (L.) (Diptera: Culicidae) is the primary vector of several arboviruses of public health importance worldwide. Resistance to insecticides led to increasing interest in exploring eco-friendly alternatives such as plant extracts used as bioinsecticides. This study describes laboratory research using neem-based varnish against adult Ae. aegypti mosquitoes. Five concentrations (0, 1, 5, 10, and 15% v/v) of neem-based varnish were evaluated against male and female Ae. aegypti by 2 hours of direct exposure. The life span of exposed Ae. aegypti mosquitoes was significantly less. LT50 ranged from 1.98-2.65 and 3.2-6.06 days for males and females, respectively, exposed to 1 to 15% concentrations of neem-based varnish. LT50 of nonexposed male and female mosquitoes were 16.20-19.60 days, respectively. The results indicated that neem-based varnish was very toxic to Ae. aegyipti mosquitoes. This botanical insecticide can be an alternative for biological control of mosquitoes

The mosquitoes (Diptera: Culicidae) of Nuevo León, Mexico, with descriptions of two new species

To document the diversity and distribution of mosquitoes inhabiting the Mexican state of Nuevo León, collection trips were conducted to all physiographic regions (Grand Northamerican Plains, Coastal Plain of North Gulf, and Sierra Madre Oriental) and subregions across the state. A total of 3,176 specimens were collected. Additionally, we re-examined mosquito specimens in two Mexican entomological collections: The Collection of Insects and Mites of Medical Importance and the Collection of Arthropods of Medical Importance. These represent the two culicid subfamilies Anophelinae and Culicinae, 8 tribes, 12 genera, 25 subgenera, and 64 named species. Of these, 1 tribe, 2 genera, 5 subgenera, and 14 species are new records for the mosquito fauna of Nuevo León. Three undescribed species were collected. Two are described in this study: Aedes (Ochlerotatus) amateuri Ortega & Zavortink n. sp., and Aedes (Protomacleaya) lewnielseni Ortega & Zavortink n. sp. The third belongs to the genus Wyeomyia. Twelve species previously recorded from Nuevo León were not collected during this study. Taxonomic notes, new distribution limits, and comments about the medical importance of some species are reported

Dengue Serotypes Circulating in Aedes aegypti and Humans in a Poor or Peripheral Neighborhood at Reynosa, Mexico

Eleven entomological variables were correlated with households seropositive (Y= 1) or seronegative (Y= 0) for dengue virus depending on the percentage of seropositive to total participants per household. DENV serotypes were identified in mosquito vectors. Three entomologic (spring, summer, and fall) and two serologic surveys (spring and fall) were done in 77 households at Reynosa, Mexico in 2014. Numbers of water-filled containers, larvae, and pupae were counted per household, and adult Aedes aegypti (L.) were collected with a backpack aspirator after landing on humans. In spring and fall, incidence of IgG and IgM dengue antibodies was determined per household and DENV serotypes in mosquitoes collected indoors. The households were infested with 1,573 female and 1,142 male Ae. aegypti. About 56 and 46% of 322 residents were participants in spring and fall, respectively, resulting in 117 and 95 positive cases for IgG/IgM in 68 and 62% of seropositive households. Recent transmission occurred in 8% of households with three IgM-positive participants and three IgG seroconversions, and all seropositive samples were DENV-2. A multivariate logistic regression indicated host-seeking females were the only explanatory variable linked to 48 seropositive households in fall, with 85% (289) clumped in 24 households. Host-seeking female mosquitoes also were correlated linearly with the number of IgG/IgM cases per household where an increase in 50 mosquitoes matched one IgG/IgM case. DENV -1 was detected in one pool of Ae. aegypti, and in another of Aedes albopictus Skuse. DENV -2 was amplified (10^7 RNA copies per milliliter) in one pool of 10 male Ae. aegypti, and at 3.40 log 10^4 in one male Ae. albopictus. DENV-1 and DENV-2 circulating in humans and mosquitoes were determined, with vertical cycles in both species of mosquito vector

Back from the past: Molecular and morphological support for Simulium mutucuna Nunes de Mello & Vieira da Silva, 1974 (Diptera: Simuliidae) as a valid species

Simulium mutucuna, a species described based on a single female from Roraima state, was previously synonymized with Simulium paynei and currently is considered a synonym of Simulium rubrithorax. In the present paper we present morphological and molecular evidence supporting the validity of S. mutucuna based on analysis of specimens from Brazil, Venezuela and Mexico. We redescribe the female and describe, for the first time, the male, pupa and larva of S. mutucuna and discuss the morphological differences between this species and the others that are already considered as its senior synonyms. Currently, the distribution of S. mutucuna is restricted to Roraima state. The distribution record for S. rubrithorax in Brazil’s North region needs to be removed, since the previous records were based on occurrence of S. mutucuna. Finally, we present new evidence of cryptic diversity in the S. paynei complex based on molecular information

Rickettsioses and other Tick-borne Diseases across the Border: Regional Focus in Chihuahua

Rocky Mountain spotted fever is of public importance from clinical and veterinary perspectives. During the last decade, cases have increased throughout Mexico, along with other tick-borne diseases. The number of cases reported has increased in northern states of the country that border the United States of America. Studies to understand the current state of affairs with the tick vector and identification of etiological agents also have increased. From the six border states, two in the northwest and central region are of special interest because of the close proximity of the populations from both regions -- Baja California (Tijuana-San Diego and Mexicali- Calexico) and Chihuahua (Ciudad Juárez-El Paso). However, not much information is available on the current situation of Rocky Mountain spotted fever and other rickettsiosis in the State of Chihuahua. Because of increased clinical cases reported, where Chihuahua was the State with the second most number of cases nationwide in 2020, the purpose of this study was to identify methods of detection and vector collection strategies in the region

Host-seeking Aedes aegypti linked to dengue seropositive households at northeasternMexico

Background & objectives: Dengue is endemic in the cities along the USA-Mexico border where accurate interventions against Aedesaegypti are required to curb transmission. Here, we examined the link of 11 entomological variables with households (HHs) seropositive(Y=1) or seronegative (Y=0) depending on the proportion of seropositive participants/total participants per HH, and identified the DENVserotypes in mosquito vectors. Methods: Three entomologic (spring, summer and fall) and two serologic surveys (spring and fall) wereconducted in 77 HHs in Reynosa, Mexico in 2014. Water-filled containers, larvae and pupae were recorded per HH, with adult Ae. aegypti captured with a backpack aspirator and in human landing collections (HLC). In spring and fall we determined the incidence of IgG and IgMdengue antibodies per HH, and the DENV serotypes in mosquitoes collected indoors. Results: The surveyed HHs were infested with 1573female and 1142 male Ae. aegypti. About 56% and 46% of 322 residents were participants in spring and fall, respectively resulting 117 and95 positive cases for IgG/IgM, in 68% and 62% of seropositive HHs. Recent transmission occurred at 8% HHs with three IgM-positive participants and three IgG seroconversions, and all seropositive samples were for DENV-2. A multivariate analysis showed that the host-seeking females (HSFs) (339) were the only explanatory variable linked to 48 seropositive HHs in the fall, with the 85% (289) clumped in 24HHs. Further, the HSFs were correlated linearly with the number of IgG/IgM cases/HH where an increase in 50 mosquitoes matched to oneIgG/IgM case. Finally, DENV-2 was found highly amplified (107 RNA copies/ml) in one pool of 10 male Ae. aegypti, and at 3.40 Log 10 4 in one male Ae. albopictus. Interpretation & conclusion: Dengue transmission is stable in the examined HHs. Abundance of HSF Ae.aegypti was associated to seropositive HHs, and summing our results to the literature, the four DENV serotypes circulate in humans and vectors at the bordering corridor of Reynosa - Matamoros, Mexico, where indoor interventions against HSFs in August-September are needed to halt viral amplification and transmission