Frequency of Leptospira in the Blood of Patients with Fever of Unknown Origin in Sinaloa, Mexico.

Background: Leptospira is a genus of bacteria that causes the zoonotic disease known as leptospirosis, which mainly affects countries with tropical and subtropical climates. Its prevalence may be underestimated because the initial stage of the infection is characterized by presenting a febrile condition that is easily confused with other diseases, such as dengue. This work reports the frequency of leptospirosis in the blood of patients with febrile symptoms of unknown origin. Materials and Methods: A total of 218 peripheral blood samples were analyzed from volunteer participants from Culiacan Sinaloa in June 2019, one half corresponded to patients with undiagnosed febrile symptoms and the other half to asymptomatic volunteers. Data collected included the age and sex of the participants. Leptospira was detected by qPCR using a fragment of the lipL32 gene from the bacteria's genome as a target. Fisher's exact test was used as a statistical method to estimate the relationship between the infection and the data collected. Results: The study group comprised 134 female and 84 male patients ranging from ages 1 to 92 years, averaging 41 years. In this study, Leptospira infection was identified in the blood of 22/218 participating volunteers (10.09%), of which 20/109 (18.34%) presented febrile symptoms, whereas 2/109 (1.83%) were asymptomatic. The most affected participants were women with ages between 27 and 59 years. However, the analysis of the relationship between infection and the variables studied did not show statistical significance. Conclusions: Leptospirosis was detected in blood samples from patients with undiagnosed febrile illness and asymptomatic symptoms in Sinaloa. The lipL32 gene is useful as a target in identifying Leptospira in human blood in the acute phase of the disease.

Genomic Profiling of Antibiotic-Resistant Escherichia coli Isolates from Surface Water of Agricultural Drainage in North-Western Mexico: Detection of the International High-Risk Lineages ST410 and ST617.

Aquatic environments are recognized as one of the main reservoirs for the emergence and dissemination of high-risk lineages of multidrug-resistant (MDR) bacteria of public health concern. However, the genomic characteristics of antibiotic-resistant Escherichia coli isolates from aquatic origins remain limited. Herein, we examined the antibiotic resistance and virulence genomic profiles of three E. coli recovered from surface water in northwest Mexico. Antimicrobial susceptibility testing, whole-genome sequencing (WGS), and in-depth in silico analysis were performed. Two E. coli exhibited MDR phenotypes. WGS-based typing revealed genetic diversity, and phylogenetic analysis corroborated a notable divergent relationship among the studied E. coli. One E. coli strain, harboring enterotoxigenic and extraintestinal pathogenic-associated virulence genes, was assigned to the ST4 lineage. MDR E. coli, belonging to the international high-risk clones ST410 and ST617, carried genes and mutations conferring resistance to aminoglycosides, ß-lactams, quinolones, sulfonamides, tetracyclines, and trimethoprim. This study describes, for the first time, the detection and genomic profiling of high-risk lineages of E. coli ST410 and ST617 from surface water in Mexico. Additionally, our results underscore the role of surface water as a reservoir for critical pathogenic and MDR E. coli clones and the need for the surveillance and monitoring of aquatic environments via WGS from the One Health perspective.

Natural Vertical Transmission of Dengue Virus Serotype 4 in Aedes aegypti Larvae from Urban Areas in Sinaloa, Mexico.

Dengue virus (DENV) is transmitted to humans by the bite of the vector Aedes aegypti. Several researchers have suggested that the mechanism of vertical transmission of DENV in the vector is a key aspect for the prevalence of the virus in the environment and the potentiation of epidemic outbreaks of the disease. In this context and as part of an integrated study of DENV serotypes in mosquitoes of urban areas in Sinaloa, Mexico, the presence of DENV-4 in larval stages of Ae. aegypti was evaluated to demonstrate the vertical transmission of this serotype. In total, 672 larvae of Ae. aegypti were collected in 16 sectors and were grouped into 36 pools, of which 41.66% (15/36 pools) tested positive for DENV-4, with a minimum infection rate = 22.32. The analysis of the obtained sequences showed a 98% similarity to the DENV-4 with sequences previously reported in GenBank. These results show that Ae. aegypti acts as a natural reservoir for DENV-4 in this region.

High prevalent human papillomavirus infections of the oral cavity of asymptomatic HIV-positive men.

BACKGROUND: Incidence of anal and oral infections with Human Papillomavirus (HPV) is increasing, particularly among Human Immunodeficiency Virus-positive (HIV+) men. HPV type 16 has exhibited the highest incidence and only limited data is available on other prevalent types, variants of HPV16, as well as associated factors. We were interested in identifying prevalent HPV types, variants of type 16, as well as factors associated with HPV16 infections in the oral cavity of HIV+ men who have sex with men (MSM). METHODS: A cross-sectional study of oral cavity samples from HIV+ MSM, that in a previous study were identified as positive for HPV16 in the anal canal. Cells from the oral cavity (102 samples, paired with 102 from the anal canal of same patient) were used to extract DNA and detect HPV infections using INNO-LiPA HPV Genotyping Extra II, and PCR. From these, 80 samples (paired, 40 anal and 40 oral) were used to identify variants of type 16 by sequencing. Statistical differences were estimated by the X2 test, and p values equal to or less than 0.05 were considered significant. SPSS ver. Twenty-four statistical software (IBM Corp) was used. RESULTS: We found a high prevalence of High-Risk HPV (HR-HPV) and Low-Risk HPV (LR-HPV). Patients were positive in the oral cavity for HR types; 16, 39 and 18 (80.4, 61.8 and 52.9% respectively) and LR types 11 and 6 (53.9 and 34.3% respectively). Surprisingly, only European variants of type 16 were found in the oral cavity, although American Asian (22.5%) and African (2.5%) variants were identified in the anal canal. The analysis showed that CD4 counts could be the most important risk factor associated with HR-HPV infections in the oral cavity, anal canal or both anatomical regions. The risk of infection of the oral cavity with type 18 increased in men diagnosed with HIV for more than 6 years. CONCLUSIONS: Prevalence of both HR and LR HPV's in the oral cavity of Mexican HIV+ MSM is very high. The fact that only European variants of HPV16 were found in the oral cavity suggest a possible tropism not previously described.

Therapeutic effect of treatment with metformin and/or 4-hydroxychalcone in male Wistar rats with nonalcoholic fatty liver disease.

Nonalcoholic fatty liver disease (NAFLD) is the most common liver disease in the world. Despite the impact of this pathology in the population, nowadays there is no specific treatment for this disease, focusing its treatment on risks factors. However, it is imperative the existence of a specific treatment, due to this, the aim of this study was to determine the therapeutic effect of treatment with metformin, 4-hydroxychalcone or co-treatment on male Wistar rats with NAFLD. Wistar rats were divided into two groups with free access to either tap water or 50% sucrose (NAFLD) during 25 weeks. After 20 weeks of induction each were divided into four groups that received daily p.o. administration of: i) saline solution (1 ml); ii) metformin (200 mg/kg/day); iii) 4-hydroxychalcone (80 mg/kg/day) and i.v.) co-treatment (metformin plus 4-hydroxychalcone at the doses mentioned above), for 5 weeks. In healthy rats: metformin and co-treatment modified food and total caloric intake and induced diarrhea; but none of the treatments changed the other parameters evaluated. Meanwhile in rats with NAFLD: i) metformin inhibited hepatic total cholesterol and TGF-ß, increased diarrhea frequency, and slightly decreased liver steatosis, and fibrosis; ii) 4-hydroxychalcone decreased IL-6, TNF-α and TGF-ß, increased IL-10, and markedly decreased liver steatosis and fibrosis; and iii) co-treatment markedly decreased food intake, total caloric intake, and body weight, increased diarrhea; increased IL-10, showing and intermediate effect on decrease TNF-α, TGF-ß, liver steatosis and fibrosis. Our results showed that 4-hydroxychalcone treatment was the most effective among the treatments tested against NAFLD.

First report of autochthonous canine leishmaniasis caused by Leishmania (L.) mexicana in Sinaloa, Mexico.

Leishmaniasis is a neglected tropical disease caused by different species of protozoan parasites of the genus Leishmania. Dogs have been proven as primary hosts of the parasite. Cases of cutaneous leishmaniasis in humans caused by Leishmania mexicana have been reported in Sinaloa; however, the vectors and hosts involved in the epidemiology of the parasite in northwestern Mexico are still unknown. Given the public health implications of this parasite's domestic hosts regarding the permanence and transmission of the disease to humans, the objective of the present study was to detect and determine the species of Leishmania that caused the first three cases of autochthonous canine leishmaniasis in the state of Sinaloa, Mexico. Three domestic dogs showing symptoms similar to canine leishmaniasis were identified, including chronic eye inflammation, corneal opacity, ocular exudate, emaciation and hyporexia. DNA was extracted from venous blood of the infected animals using a commercial kit. The internal transcribed spacer (ITS-1) of ribosomal DNA (rDNA) was amplified by specific primers for Leishmania from the extracted DNA, and the PCR products were digested with the restriction enzyme HaeIII. In addition, PCR products were subjected to automated sequencing. Molecular analysis showed that the infecting species was L. mexicana. This is the first report of autochthonous canine leishmaniasis caused by L. mexicana in Sinaloa, Mexico. Further studies are required to identify the species that serve as vectors and other wild and domestic hosts of the parasite, as well as to determine if there are more species of Leishmania circulating in Sinaloa.

Histopathological and biochemical changes in the development of nonalcoholic fatty liver disease induced by high-sucrose diet at different times.

The high intake of sweetened drinks is associated with obesity and insulin resistance. These pathologies are directly related to the development of nonalcoholic fatty liver disease (NAFLD), considered a condition of metabolic syndrome (MS). Due to their increasing worldwide prevalence, experimental animal models have been developed to gain a better understanding of its physiopathology; notwithstanding, few studies have evaluated its progression in association with MS and ingestion of sweetened drinks. Therefore, the aim of this study was to understand the pathophysiologic characteristics of NAFLD related to sucrose concentration and time of ingestion in rats. Wistar rats were divided into 2 groups with free access to either tap water or 30% sucrose, and euthanized at 12, 16, or 20 weeks; and 2 additional groups were given free access to either 40% or 50% sucrose and were euthanized at 20 weeks. Biochemical parameters and levels of serum cytokines were measured, and histology was performed. Ingestion of 30% sucrose induced liver steatosis until 16 weeks (grade 2) and 20 weeks (grade 3). Meanwhile, during 20 weeks, 40% sucrose induced grade 5 of nonalcoholic steatohepatitis (NASH) and 50% sucrose induced grade 6 of NASH and fibrosis. This study demonstrated that increasing time of induction and concentration of sucrose ingestion resulted in a higher grade of NAFLD.

High frequency of HPV16 European variant E350G among Mexican women from Sinaloa.

BACKGROUND & OBJECTIVES: Human papillomavirus (HPV) infections play a crucial role in the aetiology of cervical cancer (CC), and HPV16 is the primary viral genotype associated with CC. A number of variants of the HPV16 E6 gene are involved in the progression of CC, differing in their prevalence and biological and biochemical properties. This study was designed to determine the frequency of HPV types 16/18 and to identify the presence of HPV16 E6-variants in asymptomatic Mexican women. METHODS: A total of 189 cervical Pap smears were collected from women attending public health services in three different cities in Sinaloa, Mexico. Viral DNA was identified by amplification of E6 viral gene fragments using polymerase chain reaction (PCR). Identification of variants was done by sequencing a DNA fragment (321bp) of the HPV16 E6 gene. RESULTS: More than half of the women tested were HPV-positive (52.38%), with HPV16 being the most frequent genotype (21.16%), followed by HPV18 (8.99%). Sequence analysis of the E6-HPV16 PCR products showed that in all cases, the viruses corresponded to European variants. It was further observed that the E350G intra-variant was the most common (>76%). INTERPRETATION & CONCLUSIONS: This study showed a predominance of European lineage variants of HPV16 among asymptomatic women from Sinaloa, Mexico, predominantly with of the E350G variant. This variant has been shown to be associated with an increased risk of early development of CC. The use of molecular identification of carcinogenic HPV and Pap test screening may be a good strategy for monitoring women to prevent CC.

First Evidence of Vertical Infection of Dengue Virus 2 in Aedes aegypti Mosquitoes from Sinaloa, Mexico.

Fourteen pools of Aedes aegypti larvae collected within the urban area of Culiacán, Sinaloa, were analyzed by RT-PCR. The results demonstrate, for the first time, the vertical infection of serotype-2 dengue virus (DENV-2) in Sinaloa, Mexico, suggesting that Ae. aegypti acts as a natural reservoir of DENV-2 in this region.

First Record of Aedes albopictus in Sinaloa, Mexico.

We report here the discovery of Aedes albopictus for the first time in Sinaloa state, Mexico. The mosquito larvae were collected from small water containers in the urban area of Culiacan city, Sinaloa state. Identification of the species was done primarily by morphology, followed by confirmation with polymerase-chain-reaction-based molecular method.

Immunoproteomic Identification of p29 Antigen as the Elongation Factor-1α of Leishmania mexicana.

Previously, we identified five Leishmania mexicana antigens reacting with antibodies from cutaneous leishmaniasis patients, designated on the basis of their molecular weights as p26 (pI 7.8), p27 (pI 8.1), p28 (pI 8.6), p29 (pI 8.5), and p31 (pI 9.0). Among these antigens, p29 was most strongly recognized by the antibodies. Thereafter, p29 was identified as elongation factor-1α (EF-1α) of Leishmania mexicana through mass spectrometry analysis and western blot using a commercial antibody that reacted with EF-1α from different species. Our results showed that the p29 antigen of Leishmania mexicana is EF-1α.

Histopathological changes in third-instar and adult Anastrepha ludens (Diptera: Tephritidae) after in vitro heat treatment.

The Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae), is one of the most harmful pests of mango causing direct damage by oviposition on the fruit pulp. Mango for export is subjected to hydrothermal treatment as a quarantine method for the control of this pest, but exposure to heat for long periods of time reduces considerably the quality and shelf-life of treated fruit. The aim of this work was to study morphological changes of third-instar larvae and adults of A. ludens after in vitro exposure to high temperature at sublethal times. A heating block system was used to expose larvae at 46.1°C for 19.6 and 12.9 min, producing 94.6 and 70% mortality, respectively. Treated larvae were processed for optical microscopy. A fraction of surviving treated larvae was separated into containers with artificial diet to allow development into adults. Adult sexual organs were dissected and processed for transmission electron microscopy analysis. Results showed that 94.6% of the treated larvae died at 46.1°C for 19.6 min and none of the surviving larvae eclosed to adulthood, as they developed as malformed puparia. For the in vitro treatment at 46.1°C during 12.9 min, 70% of the treated larvae died and only 3.75% reached the adult stage, but ultrastructural damage in the male testes and in the female ovaries was observed. Additionally, 11.1% of the adult flies from the in vitro treatment also showed wing malformation and were incapable of flying. The analysis showed that surviving flies were unable to reproduce.

Spontaneous cure after natural infection with Gnathostoma turgidum (Nematoda) in Virginia opossums (Didelphis virginiana).

Seasonality of the nematode Gnathostoma turgidum in Virginia opossums (Didelphis virginiana) in the wild has been reported; however, the mechanisms involved in deworming are unknown. We monitored the parasitologic and biologic changes in four Virginia opossums naturally infected with G. turgidum by coproparasitologic examination and abdominal ultrasonography. Eggs became detectable in the feces of opossums in May, peaked in July and August, and suddenly decreased in October. Adults of G. turgidum were expelled in the feces mainly in September. Ultrasonography of the liver showed slight damage during May. Lesions in the stomach appeared in April and persisted until September. The abnormalities of the liver and stomach were resolved in November. These data suggest that G. turgidum is likely expelled as a result of host immunologic mechanisms, although termination of a natural life span cannot be definitively excluded.

Prevalence of Salmonella enterica serovar Albany in captive zoo wild animals in the Culiacán Zoo in Mexico.

Salmonellosis is an important zoonotic disease but little is known about the role that free-living animals play as carriers of this pathogen. Moreover, the primary route of infection in the wild needs to be elucidated. The aim of this study was to determine the source and the route of transmission of Salmonella enterica serovar Albany (S. Albany) infection in captive zoo wild animals in the Culiacán Zoo. A total of 267 samples were analyzed including 220 fecal samples from zoo animals, 15 fecal samples from rodents, 5 pooled samples each of two insects (Musca domestica and Periplaneta americana), and 22 samples of animal feed. We detected S. Albany in 28 (10.5%) of the samples analyzed, including in samples from raw chicken meat. Characterization of isolates was performed by serotyping and pulsed-field gel electrophoresis. All isolates shared a single pulsed-field gel electrophoresis profile, indicating a possible common origin. These data suggest that the infected meat consumed by the wild felines was the primary source of infection in this zoo. It is likely that the pathogen was shed in the feces and disseminated by insects and rats to other locations in the zoo.

Molecular diagnosis of Leishmania mexicana in a cutaneous leishmaniasis case in Sinaloa, Mexico.

Leishmaniasis has been considered endemic in Sinaloa, Mexico, since 1994. Despite that Leishmania mexicana is the main etiological agent of cutaneous leishmaniasis (CL) in other regions of Mexico, the species causing CL in patients from Sinaloa state has not been previously established, although Leishmania braziliensis has been found in the neighboring southern state, Nayarit. L. braziliensis is also associated with mucocutaneous leishmaniasis, which is a more complicated clinical variant. Due to the implications on individual and public health, the objective of this report was to identify the Leishmania species present in Sinaloa, Mexico. Using the first internal transcribed spacer (ITS-1) polymerase chain reaction-restriction fragment length polymorphism, we identified L. mexicana in a CL patient from Sinaloa and confirmed the extended distribution of this parasite in Mexico.

Relación del polimorfismo TaqI del gen del receptor de la vitamina D con la lepra lepromatosa en población mexicana / Association between the TaqI polymorphism of Vitamin D Receptor gene and lepromatous leprosy in a Mexican population sample

OBJETIVO: Determinar la relación del polimorfismo TaqI del gen del receptor de la vitamina D (RVD) con la lepra lepromatosa (LL) en individuos originarios de Sinaloa, México. MATERIAL Y MÉTODOS: Se amplificó un fragmento de 740 pb del gen RVD en muestras de ADN de 71 pacientes con LL y 144 controles en el Hospital General de Culiacán durante el periodo 2004-2007. El polimorfismo se identificó mediante la endonucleasa TaqI. RESULTADOS: Se observó un aumento de relevancia estadística del genotipo TT en pacientes con LL en comparación con los controles (p= 0.040; RM= 1.82). CONCLUSIÓN: Se demuestra un nexo entre el genotipo TT y la susceptibilidad a la LL.

OBJETIVE: To establish the association of the vitamin D receptor gene TaqI polymorphism with lepromatous leprosy (LL) in individuals from Sinaloa, Mexico. MATERIAL AND METHODS: A 740 bp fragment was amplified from the VDR gene in DNA samples of 71 patients with LL and 144 controls in the Hospital General de Culiacán during 2004-2007. Polymorphism was identified through TaqI endonuclease. RESULTS: A significant increase in the genotype TT of the VDR gene was observed in patients when compared to controls (p = 0.040; OR = 1.82). CONCLUSIONS: Our data support the association between the TT genotype and susceptibility to LL in this Mexican population.

[Association between the TaqI polymorphism of the vitamin D receptor gene and lepromatous leprosy in a Mexican population sample]. / Relación del polimorfismo TaqI del gen del receptor de la vitamina D con la lepra lepromatosa en población mexicana.

OBJECTIVE: To establish the association of the vitamin D receptor gene TaqI polymorphism with lepromatous leprosy (LL) in individuals from Sinaloa, Mexico. MATERIAL AND METHODS: A 740 bp fragment was amplified from the VDR gene in DNA samples of 71 patients with LL and 144 controls in the Hospital General de Culiacán during 2004-2007. Polymorphism was identified through TaqI endonuclease. RESULTS: A significant increase in the genotype TT of the VDR gene was observed in patients when compared to controls (p = 0.040; OR = 1.82). CONCLUSIONS: Our data support the association between the TT genotype and susceptibility to LL in this Mexican population.

[Cutaneous leishmaniasis caused by Leishmania mexicana in Durango, Mexico: first clinical case report]. / Leishmaniasis cutánea causada por Leishmania mexicana en Durango, Mexico. Informe del primer caso clínico.

BACKGROUND: Leishmanisis is a parasitic diseases caused by intracellular protozoan of Leishmania genus. These parasites are transmitted by the bite of phlebotomine flies. Leishmanises are classified in different clinic variants: cutaneous localized or diffuse, mucocutaneous and visceral. In Mexico, the leishmanisis are distributed in several states, however Durango was considered free of leishmaniasis. CLINICAL CASE: A 9 year old male patient with an ulcerated pruriginous node of circular shape, 13 x 18 mm diameter, localized in the back of the right arm with 6 months progression. The patient was a permanent resident of Durango, Mexico. Histopathology evidenced macrophages infected with amastigotes. The PCR-RFLP result was consistent with Leishmania mexicana. Treatment with glucantime was satisfactory. CONCLUSIONS: Here we report the first clinical case of leishmanisis cutaneous localized caused by Leishmania mexicana from Durango, Mexico in a 9 years old male, confirming the increasing propagation of this protozoan parasite in Mexico.

Discovery of an endemic area of Gnathostoma turgidum infection among opossums, Didelphis virginiana, in Mexico.

Gnathostomosis, caused by Gnathostoma binucleatum, is a serious public health issue in Mexico. Although 2 other Gnathostoma spp., G. turgidum and G. lamothei, have been found in wild animals, their natural life cycle or their relation to human disease remains unclear. While we were conducting an epidemiological survey on Gnathostoma spp. in Sinaloa State, Mexico, we found an endemic area for G. turgidum in common opossums, Didelphis virginiana, located in Tecualilla, Sinaloa. The species identification was carried out by morphological and molecular biological methods. This is the first record of an endemic area for G. turgidum infection in opossums, D. virginiana, in the Americas.