Spotted Fever and Typhus Group Rickettsiae in Dogs and Humans, Mexico, 2022.

We found serologic evidence of spotted fever group Rickettsia in humans and dogs and typhus group Rickettsia in dogs in Reynosa, Mexico. Our investigation revealed serologic samples reactive to spotted fever group Rickettsia in 5 community members, which highlights a potential rickettsial transmission scenario in this region.

Domestic Dogs as Sentinels for West Nile Virus but not Aedes-borne Flaviviruses, Mexico.

We tested 294 domestic pet dogs in Mexico for neutralizing antibodies for mosquito-borne flaviviruses. We found high (42.6%) exposure to West Nile virus in Reynosa (northern Mexico) and low (1.2%) exposure in Tuxtla Gutierrez (southern Mexico) but very limited exposure to Aedes-borne flaviviruses. Domestic dogs may be useful sentinels for West Nile virus.

Exploitation of Mangrove Endophytic Fungi for Infectious Disease Drug Discovery.

There is an acute need for new and effective agents to treat infectious diseases. We conducted a screening program to assess the potential of mangrove-derived endophytic fungi as a source of new antibiotics. Fungi cultured in the presence and absence of small molecule epigenetic modulators were screened against Mycobacterium tuberculosis and the ESKAPE panel of bacterial pathogens, as well as two eukaryotic infective agents, Leishmania donovani and Naegleria fowleri. By comparison of bioactivity data among treatments and targets, trends became evident, such as the result that more than 60% of active extracts were revealed to be selective to a single target. Validating the technique of using small molecules to dysregulate secondary metabolite production pathways, nearly half (44%) of those fungi producing active extracts only did so following histone deacetylase inhibitory (HDACi) or DNA methyltransferase inhibitory (DNMTi) treatment.

Association of KIR3DL1/S1 and HLA-Bw4 with CD4 T cell counts in HIV-infected Mexican mestizos.

Certain genotypic combinations of killer-cell immunoglobulin-like receptors (KIR) and human leukocyte antigens (HLA) have been associated with favourable outcomes after exposure to human immunodeficiency virus in Caucasoid and African populations. Human immunodeficiency virus (HIV) infection is characterized by a rapid exhaustion of CD4 cells, which results in impaired cellular immunity. During this early phase of infection, it is thought that the natural killer (NK) cells represent the main effector arm of the host immune response to HIV. This study investigates whether KIR and HLA factors are associated to CD4 T cell numbers after HIV infection in Mexican mestizos as assessed at the time of initial medical evaluation and subsequent clinical follow-up. KIR and HLA-B gene carrier frequency differences were compared between groups of patients stratified by CD4 T cell numbers as assessed during their first medical evaluation (a point in time at which all patients were anti-retroviral therapy naïve). In addition, the influence that these genetic factors have on averaged historical CD4 cell counts in patients subjected to follow-up (mostly therapy-experienced) was also evaluated. Our results suggest a protective role for the HLA-Bw4 and KIR3D + Bw4 combination in both therapy-naïve and therapy-experienced patients. This report furthers our understanding on the way that immune genes modulate HIV disease progression in less-studied human populations such as the Mexican mestizos with a special focus on CD4 T cell number and behaviour.

[Control of Aedes aegypti breeding sites with the program Recicla por tu bienestar in Merida, Mexico]. / Control de criaderos de Aedes aegypti con el programa Recicla por tu bienestar en Mérida, México.

OBJECTIVES: To determine the importance of Ae. aegypti breeding-sites in Merida;to evaluate the impact of Recicla por tu bienestar (RxB, a recycling program) on the reduction of breeding sites and the perception of participants. MATERIALS AND METHODS: The relative importance for pupae production of the different types of breeding-sites was determined. Pre-and post-RxB entomological surveys were performed in participant neighborhoods to evaluate the impact on total containers and positive breeding-sites. A survey on the perception of participating people about dengue prevention and control and RxB was applied. RESULTS: Buckets/pots and "small diverse items" were the most important breeding-sites. RxB had a significant impact in the reduction of total containers (IRR = 0.74), positive containers (IRR = 0.33) and the risk of a house being positive for Ae. aegypti (OR = 0.41). All the interviewed participants referred RxB as needed and most consider it useful. CONCLUSIONS: RxB should be considered as a good practice for the dengue vector control.

The detection of inherent homologous recombination between repeat sequences in H. pylori 26695 by the PCR-based method.

Helicobacter pylori infects more than half of the world's population, making it the most widespread infection of bacteria. It has high genetic diversity and has been considered as one of the most variable bacterial species. In the present study, a PCR-based method was used to detect the presence and the relative frequency of homologous recombination between repeat sequences (>500 bp) in H. pylori 26695. All the recombinant structures have been confirmed by sequencing. The inversion generated between inverted repeats showed distinct features from the recombination for duplication or deletion between direct repeats. Meanwhile, we gave the mathematic reasoning of a general formula for the calculation of relative recombination frequency and indicated the conditions for its application. This formula could be extensively applied to detect the frequency of homologous recombination, site-specific recombination, and other types of predictable recombination. Our results should be helpful for better understanding the genome evolution and adaptation of bacteria.

Grass Infusions in Autocidal Gravid Ovitraps to Lure Aedes Albopictus.

Aedes albopictus is a vector of several pathogens of significant public health concern. In this situation, gravid traps have become a common surveillance tool for Aedes spp., which commonly use hay infusions as an attractant. Diverse grass infusions have been assessed to enhance the attraction to this vector mosquito. However, these studies have focused on the oviposition effect, and the attraction potential to gravid Ae. albopictus females has not been evaluated yet. Here we report the attractiveness of infusions of 4 different botanical species (Cenchrus purpureus, Cyanodon dactylon, Megathyrus maximus, Pennisetum ciliare) as baits in sticky ovitraps and autocidal gravid ovitraps (AGOs) under laboratory, semifield, and field conditions. In the laboratory, Cynodon dactylon showed attractiveness, whereas in semifield conditions, both C. dactylon and Megathyrsus maximus were similarly attractive for gravid Ae. albopictus. None of the infusions conducted with AGOs were able to lure Ae. albopictus and other species of mosquitoes in a 14-wk field experiment. Our results demonstrate the feasibility of finding more attractive infusions for Ae. albopictus females to improve the efficacy of AGO traps, but further testing of infusions in AGOs in field settings is needed.

FIRST RECORDS OF AEDES TORMENTOR AND CULEX PANOCOSSA AS A RESULT OF VECTOR SURVEILLANCE ACTIVITIES CONDUCTED DURING THE CHARACTERIZATION OF FOCI OF EASTERN EQUINE ENCEPHALITIS IN TAMAULIPAS, MEXICO.

We report the 1st records of Aedes tormentor and Culex panocossa throughout vector surveillance events carried out in putative foci of eastern equine encephalitis in Tamaulipas, Mexico. Formerly, Ae. tormentor had been reported in, at least, 2 Central American countries and Mexico. In Mexico, reports were from the states of Campeche, Chiapas, Quintana Roo, and Veracruz. Records of Ae. tormentor in these 4 Neotropical states were recently reviewed and eliminated; thus, the southernmost geographic distribution for this species is considered to be the state of Tamaulipas Mexico in its neotropical zone. Further, Cx. panocossa had been collected in Guerrero, Tabasco, and Veracruz. In Tamaulipas, there are 82 species of mosquitoes, being the 4th state accounting for the highest mosquito species diversity of 11 states in which comprehensive studies have been conducted on the subject of mosquito distribution.

Domestic Dog Infection with Trypanosoma cruzi from Northern and Southern Regions of Mexico.

Background: Chagas disease or American trypanosomiasis, caused by Trypanosoma cruzi and vectored by triatomines, affects millions of people worldwide. In endemic countries including Mexico, infections in domestic animals, such as dogs, may affect the risk of human disease when they serve as a source of infection to vectors that subsequently infect humans. Materials and Methods: We conducted a cross-sectional study of 296 dogs from two cities near the northern and southern borders of Mexico: Reynosa, Tamaulipas, and Tuxtla Gutierrez, Chiapas. Infection was measured based on testing of blood using T. cruzi quantitative PCR (qPCR) and up to three antibody detection assays. The StatPak immunochromatographic assay was used to screen samples and the indirect fluorescent antibody (IFA) and multiplex microsphere immunoassay (MIA) tests were used as secondary tests on all samples that screened positive and a subset of negatives. Serologic positivity was defined based on reactivity on at least two independent tests. Results: Of the 280 samples tested for parasite DNA, two (0.7%) were positive, one of which (0.4%) was confirmed as T. cruzi discrete typing unit TcIV. Overall, 72 (24.3%) samples were reactive for T. cruzi antibodies via StatPak of which 8 were also positive using MIA and 2 were also positive using IFA (including one of the PCR-positive dogs). Overall, nine dogs (3.4%) met study criteria of positivity based on either/both serology or PCR tests. Positive dogs were found in both regions of Mexico; five (2.7%) from Reynosa and four (3.6%) from Tuxtla Gutierrez. We found no association between infection status and state of origin, sex, age group, breed group, neighborhood, and whether other pets lived in the home. Conclusion: Our results re-emphasize dogs' utility as sentinels for T. cruzi in Mexico and underscore the need for improved veterinary diagnostic tests and parasite surveillance at the household level in endemic countries.

Ethanolic Extract of Salvia officinalis Leaves Affects Viability, Survival, Migration, and the Formation and Growth of 3D Cultures of the Tumourigenic Murine HPV-16+-Related Cancer Cell Line.

Salvia officinalis (SO) is one of the most widely used plants in traditional medicine worldwide. In the present study, the effect of an ethanolic extract of S. officinalis leaves on hallmarks of cancer of HPV-16-positive cancer tumorigenic cells, TC-1, was analyzed in vitro. Phytochemical and spectroscopic analysis were performed. Additionally, the extract's flavonoid content, reducing iron, and antioxidant capacity were determined. In regard to the in vitro tests, the cytotoxic activity and its effect on the replicative capacity and on the cell migration of TC-1 cells were analyzed by viability and clonogenic, survival, and wound healing assays. The effect of a pre-treatment or treatment on 3D culture formation, growth, and reversion capacity was also examined. The results of the phytochemical analysis allowed the detection of tannins, saponins, steroids, and flavonoids. The flavonoids content was found to be 153.40 ± 10.68 µg/mg of extract. Additionally, the extract exhibited an antioxidant capacity and a ferric-reducing capacity of around 40% compared to the ascorbic acid. Thin layer chromatographic (TLC) analysis and spectroscopic tests showed the presence of compounds similar to quercetin and catechin flavonoids in the extract. In the in vitro assays, the SO extract induced in a concentration-dependent way changes in cell morphology, the decrease of cell viability, survival, and migration. At a concentration of 125 µg/mL, the extract inhibited spheroid formation, reduced their growth, and affected their reversion to 2D. Ethanolic extract of S. officinalis leaves had inhibitory effects on hallmarks of the cancer line HPV-16+. This suggests that the phytochemicals present in it may be a source of chemotherapeutics against cervical cancer.

Primary spontaneous cerebrospinal fluid leaks and idiopathic intracranial hypertension.

INTRODUCTION: Idiopathic intracranial hypertension (IIH) is increasingly recognized as a cause of spontaneous cerebrospinal fluid (CSF) leak in the otolarnygological and neurosurgical literature. The diagnosis of IIH in patients with spontaneous CSF leaks typically is made a few weeks after surgical repair of the leak when symptoms and signs of elevated intracranial pressure (ICP) appear. METHODS: Case reports and literature review. Two young obese women developed spontaneous CSF rhinorrhea related to an empty sella in one and a cribriform plate encephalocele in the other. Both patients underwent surgical repair of the CSF leak. A few weeks later, they developed chronic headaches and bilateral papilledema. Lumbar punctures showed elevated CSF opening pressures with normal CSF contents, with temporary improvement of headaches. A man with a 3-year history of untreated IIH developed spontaneous CSF rhinorrhea. He experienced improvement of his headaches and papilledema after a CSF shunting procedure, and the rhinorrhea resolved after endoscopic repair of the leak. RESULTS: These cases and the literature review confirm a definite association between IIH and spontaneous CSF leak based on: 1) similar demographics; 2) increased ICP in some patients with spontaneous CSF leak after leak repair; 3) higher rate of leak recurrence in patients with raised ICP; 4) patients with intracranial hypertension secondary to tumors may develop CSF leak, confirming that raised ICP from other causes than IIH can cause CSF leak. CONCLUSIONS: CSF leak occasionally may keep IIH patients symptom-free; however, classic symptoms and signs of intracranial hypertension may develop after a CSF leak is repaired, exposing these patients to a high risk of recurrence of the leak unless an ICP-lowering intervention is performed.

Detection of Onchocerca volvulus in Latin American black flies for pool screening PCR using high-throughput automated DNA isolation for transmission surveillance.

The posttreatment entomological surveillance (ES) of onchocerciasis in Latin America requires quite large numbers of flies to be examined for parasite infection to prove that the control strategies have worked and that the infection is on the path of elimination. Here, we report a high-throughput automated DNA isolation of Onchocerca volvulus for PCR using a major Latin American black fly vector of onchocerciasis. The sensitivity and relative effectiveness of silica-coated paramagnetic beads was evaluated in comparison with phenol chloroform (PC) method which is known as the gold standard of DNA extraction for ES in Latin America. The automated method was optimized in the laboratory and validated in the field to detect parasite DNA in Simulium ochraceum sensu lato flies in comparison with PC. The optimization of the automated method showed that it is sensitive to detect O. volvulus with a pool size of 100 flies as compared with PC which utilizes 50 flies pool size. The validation of the automated method in comparison with PC in an endemic community showed that 5/67 and 3/134 heads pools were positive for the two methods, respectively. There was no statistical variation (P < 0.05) in the estimation of transmission indices generated by automated method when compared with PC method. The fact that the automated method is sensitive to pool size up to 100 confers advantage over PC method and can, therefore, be employed in large-scale ES of onchocerciasis transmission in endemic areas of Latin America.

Aedes albopictus in northeast Mexico: an update on adult distribution and first report of parasitism by Ascogregarina taiwanensis.

BACKGROUND & OBJECTIVES: Aedes albopictus has been known as efficient vector of dengue in Asian countries and its wide displacement of Ae. aegypti has been documented in many parts of the world. The present survey was carried out to update the distribution of Ae. albopictus in northeast Mexico and to report the first record of parasitism of mosquitoes by Ascogregarina taiwanensis in Mexico. METHODS: Human landing collections were conducted in the month of May every year between 2007 and 2009 across the three states, Nuevo Leon (NL), Tamaulipas and Coahuila in northeast Mexico. Six human bait collections were also organized at the cemetery of Gomez Farias (GF), a village in southern Tamaulipas during the rainy and dry seasons in 2010. Aedes albopictus caught in 2010 were dissected for parasitic protozoan gregarines. RESULTS: The results of human landing collections carried out during 2007-10 across the three states of northeast zone of Mexico revealed that Ae. albopictus is invading along the route between Monterrey City in NL and Tampico, Tamaulipas, but not into the arid state of Coahuila. Aedes albopictus was recorded in nine new municipalities in addition to the 15 municipalities reported before 2005. Furthermore, six human-bait collections performed during the dry and rainy seasons in 2010 at the cemetery of GF suggest the exclusion of Ae. aegypti on that site. Dominance was shared by Ae. quadrivittatus, another container-inhabitant but indigenous species, and Ae. albopictus during the dry and rainy seasons, respectively. The results of dissection of the mosquitoes for gregarines revealed the parasitism of Ae. albopictus by A. taiwanensis. INTERPRETATION & CONCLUSION: The results of this study showed that Ae. albopictus has spread to all the municipalities in the northeastern Mexico except the arid area and reported the first record of parasitic protozoan A. taiwanensis in Mexico. We recommend further studies on larval and adult populations of natural container-occupant mosquitoes in northeastern Mexico in order to have a better documentation of the impact of Ae. albopictus upon the indigenous species community, and its epidemiological role in dengue transmission.

Non-mydriatic ocular fundus photography and telemedicine: past, present, and future.

Non-mydriatic ocular fundus photography is a promising alternative to direct ophthalmoscopy, particularly when combined with telemedicine. This review discusses these technologies from a longitudinal perspective: past, present, and future. The focus is directed to the role that non-mydriatic fundus photography and telemedicine have played in medical research and patient care, with emphasis on the major advances to date. Also discussed are the challenges to their widespread application and their substantial promise for revitalizing the importance of the ocular fundus examination in patient care, providing improved access to ophthalmic consultative services, and facilitating clinical and epidemiologic research.

A generalized Poisson model to predict host-seeking female Aedes aegypti marked by dusted Metarhizium anisopliae-exposed males.

We developed a biological control method directed toward Aedes aegypti using the release of Metarhizium anisopliae-contaminated males to spread the fungus to wild females. A generalized Poisson model was used to relate Ae. aegypti marked females (MKF) to M. anisopliae-exposed males (FEM). In a mark-recapture parallel arm trial, FEM release was a better predictor than unexposed male (UM) releases to forecast MKF by FEM. Total females (TF), marked males (MKM), and wild males (WM) as predictors were counted in human-landings in 15 households treated with 40 FEM each, vs 40 UM released/household/week in 15 households for eight weeks. Fit of MKF to standard, generalized Poisson (GP), and negative binomial models/arm built by TF, MKM, WM, and interactions as predictors were computed. In both arms, MKF was better modeled by GP, which in treated, all but one of the eight observed data fell within the confidence intervals predicted by the model. However, the control GP had two outliers and MKM as a single predictor. Likewise, the pseudo-R2 measures of 95% and 46% for treated and control groups also showed that the GP with FEM was more suitable to predict MKF. It should thus be possible to use the GP model to indirectly estimate that an increase of one TF or one fungus-exposed male would increase the number of marked-females by 8% or 9%, respectively, while wild males were an irrelevant predictor to the model.

Daytime Resting Activity of Aedes Aegypti and Culex Quinquefasciatus Populations in Northern Mexico.

Aedes aegypti and Culex quinquefasciatus are disease vectors distributed throughout much of the world and are responsible for a high burden of vector-borne disease, which has increased during the last 2 decades. Most pathogens vectored by these mosquitoes do not have therapeutic remedies; thus, combating these diseases is dependent upon vector control. Improvements in vector control strategies are urgently needed, but these hinge on understanding the biology and ecology of Ae. aegypti and Cx. quinquefasciatus. Both species have been extensively investigated, but further knowledge on diel resting activity of these vectors can improve vector surveillance and control tools for targeting resting vector populations. From April to December 2021, we determined outdoor daytime resting habits of Ae. aegypti and Cx. quinquefasciatus male, female, and blood-fed female populations in Reynosa, Mexico, using large red odor-baited wooden box traps. The daytime resting activity for Ae. aegypti males, females, and blood-fed females was restricted to a period between 0900 h and 1300 h, with a peak at 0900 h, while the resting activity of Cx. quinquefasciatus male, female, and blood-fed females was between 0700 h and 1100 h, with a peak at 0700 h. A generalized additive model was developed to relate relative humidity and temperature to resting Cx. quinquefasciatus and Ae. aegypti male, female, and blood-fed populations caught in traps. This study advances the understanding of outdoor resting behavior for 2 important vector mosquito species and discusses future studies to fill additional knowledge gaps.

Antimicrobial peptides with cell-penetrating activity as prophylactic and treatment drugs.

Health is fundamental for the development of individuals and evolution of species. In that sense, for human societies is relevant to understand how the human body has developed molecular strategies to maintain health. In the present review, we summarize diverse evidence that support the role of peptides in this endeavor. Of particular interest to the present review are antimicrobial peptides (AMP) and cell-penetrating peptides (CPP). Different experimental evidence indicates that AMP/CPP are able to regulate autophagy, which in turn regulates the immune system response. AMP also assists in the establishment of the microbiota, which in turn is critical for different behavioral and health aspects of humans. Thus, AMP and CPP are multifunctional peptides that regulate two aspects of our bodies that are fundamental to our health: autophagy and microbiota. While it is now clear the multifunctional nature of these peptides, we are still in the early stages of the development of computational strategies aimed to assist experimentalists in identifying selective multifunctional AMP/CPP to control nonhealthy conditions. For instance, both AMP and CPP are computationally characterized as amphipatic and cationic, yet none of these features are relevant to differentiate these peptides from non-AMP or non-CPP. The present review aims to highlight current knowledge that may facilitate the development of AMP's design tools for preventing or treating illness.

SARS-CoV-2 Infections in a High-Risk Migratory Population Arriving to a Migrant House along the US-Mexico Border.

Few reports exist on the COVID-19 epidemiology of migrant populations. We tested 370 migratory individuals from ten countries arriving at a migrant house along the US-Mexico border based on a rapid assay detecting SARS-CoV-2 antigen. Fifty-six were positive, for a prevalence of 15.1% (95%-CIs of 11.8-19.2%). Only 21 positive persons presented signs or symptoms associated with the infection (95%-CIs = 25-49%). Most (51.7%) positive migrants arrived in the previous two days before being tested, indicating that the virus infection was acquired during their transit. Out of the total of 56 positive individuals, 37.5% were from El Salvador, 33.9% from Honduras, and 21.4% from Guatemala. This study suggests that vulnerable populations traveling from countries in Latin America and seeking residence in the US are high-risk individuals for exposure to SARS-CoV-2. The rapid antigen COVID-19 testing on arrival at the migrant house, and subsequent 10-day quarantine, was a critical step to help minimize further transmission. Therefore, the present study demonstrates that public health services provided to migratory and vulnerable populations are necessary for pandemic control.

Increased Attraction and Stability of Beauveria bassiana-Formulated Microgranules for Aedes aegypti Biocontrol.

Aedes aegypti (Linn.) incidence has increased in recent years, causing human viral diseases such as dengue, which are often fatal. Beauveria bassiana (Bals., Vuillemin) efficacy for Ae. aegypti biological control has been evidenced but it relies on host susceptibility and strain virulence. We hypothesized that B. bassiana conidia microgranular formulations (MGF) with the additives acetone, lactic acid, and sugar increase Ae. aegypti adult exposure, thus improving their biocontrol effectiveness. Beauveria bassiana strain four (BBPTG4) conidia stability was assessed after 0 d, 5 d, and 30 d storage at 25 °C ± 2 °C with additives or in MGF after 91 d of storage at 25 °C ± 2 °C or 4 °C ± 1 °C, whereas mortality was evaluated after adult exposure to MGF + conidia, using home-made traps. Additives did not show toxicity to conidia. In addition, we observed that sugar in MGF increased Ae. aegypti adults' attraction and their viability resulted in a 3-fold reduction after 5 d and 1- to 4-fold decrease after 30 d of storage, and formulations were less attractive (p < 0.05). Conidia stability was higher on MGF regardless of the storage temperature, losing up to 2.5-fold viability after 91 d. In conclusion, BBPTG4 infected and killed Ae. aegypti, whereas MGF attracting adults resulted in 42.2% mortality, increasing fungus auto dissemination potential among infected surviving adults. It is necessary to further evaluate MGF against Ae. aegypti in the field.

Domestic Triatoma spp. Infections with Trypanosoma cruzi, Household Infestations, and Molecular Identification in Oaxaca, México.

In Latin America, Mexico is the country with the second highest annual estimated number of Chagas disease cases, caused by Trypanosoma cruzi, due to vector-borne transmission. The state of Oaxaca is the location of the first documented human cases of Chagas disease in Mexico and contained the highest T. cruzi seropositive rate (3.5%) from blood donors. Here, entomological surveys, from 2017 to 2019, were conducted to collect triatomines in 124 villages of 60 municipalities. Four principal domestic Triatoma spp. (Hemiptera: Triatominae), Triatoma phyllosoma, T. barberi, T. mazzotti, and T. dimidiata, of Oaxaca, Mexico were identified by morphology and molecular analysis of the barcode region of the cytochrome oxidase 1 (cox1 or COI or CO1) gene. A total of 41 out of 83 T. phyllosoma specimens examined by microscopy were positive for T. cruzi (49%), 49 out of 171 for T. barberi (28%), 31 out of 177 for T. mazzotti (17%), and none out of 10 for T. dimidiata (0%). Overall, the infestation index was 3.1% of households containing at least one triatomine; the crowding index was a mean of two Triatoma spp./household; and the colonization index was 0.38 for households based on presence of nymphs. Geographical distribution of triatomines in Oaxaca at the municipality level and endophilic behavior is also reported. Precise identification, endophilic habits, and infection rates of these triatomines are paramount for vector control programs of the Ministry of Health of Oaxaca and beyond.