Analysis of influenza data generated by four epidemiological surveillance laboratories in Mexico, 2010-2016.

The disease caused by the influenza virus is a global public health problem due to its high rates of morbidity and mortality. Thus, analysis of the information generated by epidemiological surveillance systems has vital importance for health decision making. A retrospective analysis was performed using data generated by the four molecular diagnostic laboratories of the Mexican Social Security Institute between 2010 and 2016. Demographics, influenza positivity, seasonality, treatment choices and vaccination status analyses were performed for the vaccine according to its composition for each season. In all cases, both the different influenza subtypes and different age groups were considered separately. The circulation of A/H1N1pdm09 (48.7%), influenza A/H3N2 (21.1%), influenza B (12.6%), influenza A not subtyped (11%) and influenza A/H1N1 (6.6%) exhibited well-defined annual seasonality between November and March, and there were significant increases in the number of cases every 2 years. An inadequate use of oseltamivir was determined in 38% of cases, and the vaccination status in general varied between 12.1 and 18.5% depending on the season. Our results provide current information about influenza in Mexico and demonstrate the need to update both operational case definitions and medical practice guidelines to reduce the inappropriate use of antibiotics and antivirals.

Autodisplay of an avidin with biotin-binding activity on the surface of Escherichia coli.

OBJECTIVES: To display a recombinant avidin fused to the autotransporter ShdA to bind biotinylated molecules on the surface of Escherichia coli. RESULTS: Two chimeric protein constructs containing avidin fused to the autotransporter ShdA were expressed on the surface of Escherichia coli DH5α. One fusion protein contained 476 amino acids of the ShdA α and ß domains, whereas the second consisted of a 314 amino acid from α and truncated ß domains. Protein production was verified by SDS-PAGE using an antibody to the molecular FLAG-tag. The surface display of the avidin-shdA fusion protein was confirmed by confocal microscopy and flow cytometry analysis, and the biotin-binding activity was evaluated by fluorescence microscopy and flow cytometry using biotin-4-fluorescein and biotinylated-ovalbumin (OVA). CONCLUSIONS: Expression of a recombinant avidin with biotin-binding activity on the surface of E. coli was achieved using the autotransporter ShdA. This system is an alternative to bind biotinylated molecules to E. coli.

Establishment and cryptic transmission of Zika virus in Brazil and the Americas.

Transmission of Zika virus (ZIKV) in the Americas was first confirmed in May 2015 in northeast Brazil. Brazil has had the highest number of reported ZIKV cases worldwide (more than 200,000 by 24 December 2016) and the most cases associated with microcephaly and other birth defects (2,366 confirmed by 31 December 2016). Since the initial detection of ZIKV in Brazil, more than 45 countries in the Americas have reported local ZIKV transmission, with 24 of these reporting severe ZIKV-associated disease. However, the origin and epidemic history of ZIKV in Brazil and the Americas remain poorly understood, despite the value of this information for interpreting observed trends in reported microcephaly. Here we address this issue by generating 54 complete or partial ZIKV genomes, mostly from Brazil, and reporting data generated by a mobile genomics laboratory that travelled across northeast Brazil in 2016. One sequence represents the earliest confirmed ZIKV infection in Brazil. Analyses of viral genomes with ecological and epidemiological data yield an estimate that ZIKV was present in northeast Brazil by February 2014 and is likely to have disseminated from there, nationally and internationally, before the first detection of ZIKV in the Americas. Estimated dates for the international spread of ZIKV from Brazil indicate the duration of pre-detection cryptic transmission in recipient regions. The role of northeast Brazil in the establishment of ZIKV in the Americas is further supported by geographic analysis of ZIKV transmission potential and by estimates of the basic reproduction number of the virus.

Complete Genome Sequence of Human Respiratory Syncytial Virus Isolated in Mexico.

Human respiratory syncytial virus (HRSV) is a member of the Paramyxoviridae family, which causes lower respiratory tract infections in neonates and children younger than 5 years. Here, we report the complete genome sequence of HRSV, isolated from a nasopharyngeal swab of a pregnant woman with cardiac complications.

TUNEL-positive cells in the surgical border of an amputation due to infected diabetic foot.

Diabetic infected foot is the outcome of progressive vascular and neurological damage caused by persistent chronic hyperglycemia. Due to acute hypoxia and infection, the tissues develop extensive necrosis and gangrene, which often require amputation. The decision regarding the level of amputation relies mainly on the personal experience of the surgeon who must identify the healthy tissue without necrosis. However, tissue cells under stress may succumb before clear evidence of necrosis is present. In this study, dying cells with DNA damage were identified in the necrotic lesions and surgical borders of amputations. Therefore, the main purpose of this study was to identify apoptosis in the surgical borders of amputations required to treat infected diabetic foot. Apoptosis was identified by terminal deoxynucleotidyl transferase-mediated bio-dUTP nick-end labeling (TUNEL) in the superficial and deep tissues of wounds, and in the surgical borders of 10 consecutive adult patients with diabetes mellitus type 2 (DM2) who underwent amputation due to infected diabetic foot. The severity of the disease was classified by the Acute Physiological and Chronic Health Evaluation II (APACHE II) score on admission, and laboratory data were collected and bacteriological cultures were obtained from the lesions. The ankle/arm blood pressure index was measured, the blood flow in the affected limb was evaluated by high-resolution ultrasonography and color Doppler and pulse oximetry were performed during surgery. A total of 5 males and 5 females, aged 45-84 years (58.8 ± 14.1), were included. The APACHE II score was 2-18 points (8 ± 5.7). A total of 9 patients developed sepsis and 2 succumbed. A total of 5 patients required above-ankle amputation, and 5 required toe disarticulation. The ankle/arm blood pressure index ranged from 0.23-0.85 (0.51 ± 0.23). Apoptotic cells were found in ulcers and abscesses, and in areas without necrosis. In the surgical borders of the amputations, apoptotic cells were found in skeletal muscle, blood vessels and peripheral nerves, particularly Schwann cells. Morphometric analysis revealed that the extent of apoptosis was 2-3 logarithms higher in the surgical borders of the infected diabetic foot compared to the venous ulcers, which were used as the reference. In conclusion, apoptosis was identified in regenerating tissues within diabetic foot wounds and in the surgical borders of amputations, where the surgeon considered the tissues to be undamaged. This information suggests that apoptosis may be present before visible signs of necrosis appear in the diabetic foot and may be caused by hypoxia, acidosis or proinflammatory cytokines. The extent of apoptosis in tissues proximal to necrotic areas may anticipate the development of diabetic foot and help the surgeon to make decisions regarding the need and extent of amputation.

Trichinella spiralis: intranasal immunization with attenuated Salmonella enterica carrying a gp43 antigen-derived 30mer epitope elicits protection in BALB/c mice.

Trichinellosis is a public health problem and is considered an emergent/re-emergent disease in various countries. The etiological agent of trichinellosis is the nematode Trichinella, which infects domestic animals such as pigs and horses, as well as wild animals and humans. A veterinary vaccine could be an option to control the disease in domestic animals. Although several vaccine candidates have shown promising results, a vaccine against trichinellosis remains unavailable to date. Attenuated Salmonella strains are especially attractive live vectors because they elicit mucosal immunity, which is known to be important for the control of Trichinella spiralis infection at the intestinal level and can be administered by oral or intranasal routes. In this study, the autotransporter ShdA was used to display, on the surface of the Salmonella enterica serovar Typhimurium SL3261, the 210-239 amino acid epitope, (designated as Ag30) derived from the 43 kDa glycoprotein of T. spiralis muscle larvae. The fusion protein elicited antibodies in BALB/c mice that were able to recognize the native epitope on the surface of T. spiralis muscle larvae. Mice immunized by intranasal route with the recombinant Salmonella induced a protective immune response against the T. spiralis challenge, reducing by 61.83% the adult burden at day eight postinfection. This immune response was characterized by the induction of antigen-specific IgG1 and of IL-5 production. This study demonstrates the usefulness of Salmonella as a carrier of nematode epitopes providing a surface display system for intestinal parasite vaccine applications.

A fusogenic peptide expressed on the surface of Salmonella enterica elicits CTL responses to a dengue virus epitope.

Attenuated Salmonella strains are used widely as live carriers of antigens because they elicit both mucosal and systemic immunity against passenger antigens. However, they generally evoke poor cytotoxic T cell (CTL) responses because Salmonella resides within vacuolar compartments and the passenger antigens must travel to the cytosol and be processed through the MHC class I-dependent pathway to simulate CTLs. To address this problem, we designed a fusion protein to destabilize the phagosome membrane and allow a dengue epitope to reach the cytosol. The fusion protein was displayed on the bacterial surface of Salmonella enterica serovar Typhimurium SL3261 through the beta domain of the autotransporter MisL. The passenger alpha domain contained, from the N-terminus, a fusogenic sequence, the NS3 protein 298-306-amino acid CTL epitope from the dengue virus type 2, a molecular tag, and a recognition site for the protease OmpT to release it to the milieu. Display of the fusion protein on the bacterial surface was demonstrated by IFA and flow cytometry using antibodies against the molecular tag. Cleavage of the fusogenic protein-dengue peptide was demonstrated by flow cytometry using OmpT+ Escherichia coli strains. The recombinant Salmonella strains displaying the fusogenic-dengue peptide were able to lyse erythrocytes, induced specific proliferative responses, and elicited CTL responses. These results suggest that the recombinant fusion proteins containing fusogenic sequences provide a promising system to induce CTLs by live vector vaccines.