Ozone as an alternative decontamination process for N95 facemask and biosafety gowns.

COVID-19 pandemic created a global shortage of medical protective equipment. Here, we considered ozone (O3) a disinfectant alternative due to its potent oxidative activity against biological macromolecules. The O3 decontamination assays were done using SARS-CoV-2 obtained from patients to produce artificial contamination of N95 masks and biosecurity gowns. The quantification of SARS-CoV-2 was performed before and after exposing the samples to different ozone gas concentrations for times between 5 and 30 min. Viral loads as a function of the O3 exposure time were estimated from the data obtained by the RT-PCR technique. The genetic material of the virus was no longer detected for any tested concentrations after 15 min of O3 exposure, which means a disinfection Concentration-Time above 144 ppm min. Vibrational spectroscopies were used to follow the modifications of the polymeric fibers after the O3 treatment. The results indicate that the N95 masks could be safely reused after decontamination with treatments of 15 min at the established O3 doses for a maximum of 6 cycles.

Biocide effect against SARS-CoV-2 and ESKAPE pathogens of a noncytotoxic silver-copper nanofilm.

Nanometric materials with biocidal properties effective against severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) and pathogenic bacteria could be used to modify surfaces, reducing the risk of touching transmission. In this work, we showed that a nanometric layer of bimetallic AgCu can be effectively deposited on polypropylene (PP) fibers. The virucidal properties of the AgCu nanofilm were evaluated by comparing the viral loads remaining on uncoated and coated PP after contact times between 2 and 24 h. Quantification of virion numbers for different initial concentrations indicated a reduction of more than 95% after 2 h of contact. The bactericidal action of the AgCu nanofilm was also confirmed by inoculating uncoated and coated PP with a pool of pathogenic bacteria associated with pneumonia (ESKAPE). Meanwhile, no cytotoxicity was observed for human fibroblasts and keratinocyte cells, indicating that the nanofilm could be in contact with human skin without threat. The deposition of the AgCu nanofilm on the nonwoven component of reusable cloth masks might help to prevent virus and bacterial infection while reducing the pollution burden related to the disposable masks. The possible mechanism of biocide contact action was studied by quantum chemistry calculations that show that the addition of Ag and/or Cu makes the polymeric fiber a better electron acceptor. This can promote the oxidation of the phospholipids present at both the virus and bacterial membranes. The rupture at the membrane exposes and damages the genetic material of the virus. More studies are needed to determine the mechanism of action, but the results reported here indicate that Cu and Ag ions are good allies, which can help protect us from the virus that has caused this disturbing pandemic.

Epidemiological behavior and current forecast of syphilis in Mexico: increase in male population.

OBJECTIVES: Even when new cases of syphilis are notifiable since 1944, the Mexican National Epidemiological Surveillance System lacks information on the changes of the rate of case reports considering the geographic and demographic variables. Therefore, it is necessary to have evidence, with particular attention to the study of the epidemiological behavior by the identification of risk factors and groups. The objective of this study was to analyze the epidemiology, geographical distribution, and forecast of syphilis in Mexico. STUDY DESIGN: The design of the study was a secondary research of epidemiological databases. METHODS: A retrospective analysis of the national surveillance data (2007-2017) of acquired and congenital syphilis (CS) issued by the General Directorate of Epidemiology was performed. RESULTS: Of all cases, 34,998 and 1030 cases were reported for acquired syphilis (AS) and CS , respectively, reflecting an increasing trend in the whole country for both diseases. Cases and incidence of AS per year showed that, male gender presented an increase in reproductive age. Distribution of the rate of case reports is mostly commanded by the states in the extreme north (Gulf of California and northern Gulf of Mexico) and south (Gulf of southern Mexico and the Caribbean Sea). Likewise, the Seasonal Autoregressive Integrated Moving Average model was selected as the best-fit model for the forecast analysis. This model was used to forecast AS cases during 2018-2019. AS may have a slight fluctuation (on the rise) during the following 24 months. CONCLUSIONS: These findings underscore the importance of intensifying, as well as expanding screening and treatment in adult population, including men, who are not routinely benefiting from maternal and reproductive service-based syphilis screening and treatment.

Horizontal Gene Transfer and Its Association with Antibiotic Resistance in the Genus Aeromonas spp.

The evolution of multidrug resistant bacteria to the most diverse antimicrobials known so far pose a serious problem to global public health. Currently, microorganisms that develop resistant phenotypes to multiple drugs are associated with high morbidity and mortality. This resistance is encoded by a group of genes termed 'bacterial resistome', divided in intrinsic and extrinsic resistome. The first one refers to the resistance displayed on an organism without previous exposure to an antibiotic not involving horizontal genetic transfer, and it can be acquired via mutations. The latter, on the contrary, is acquired exclusively via horizontal genetic transfer involving mobile genetic elements that constitute the 'bacterial mobilome'. This transfer is mediated by three different mechanisms: transduction, transformation, and conjugation. Recently, a problem of public health due to implications in the emergence of multi-drug resistance in Aeromonas spp. strains in water environments has been described. This is derived from the genetic material transfer via conjugation events. This is important, since bacteria that have acquired antibiotic resistance in natural environments can cause infections derived from their ingestion or direct contact with open wounds or mucosal tissue, which in turn, by their resistant nature, makes their eradication complex. Implications of the emergence of resistance in Aeromonas spp. by horizontal gene transfer on public health are discussed.

Evolution of incidence and geographical distribution of Chagas disease in Mexico during a decade (2007-2016).

Chagas disease, whose aetiological agent is the protozoan Trypanosoma cruzi, mainly occurs in Latin America. In order to know the epidemiology and the geographical distribution of this disease in Mexico, the present work analyses the national surveillance data (10 years) for Chagas disease issued by the General Directorate of Epidemiology (GDE). An ecological analysis of Chagas disease (2007-2016) was performed in the annual reports issued by the GDE in Mexico. The cases and incidence were classified by year, state, age group, gender and seasons. A national distribution map showing Chagas disease incidence was generated. An increase of new cases was identified throughout the country (rates from 0.37 to 0.81 per 100 000 inhabitants). Of the total cases accumulated (7388), the major cases were attributed to the states of Veracruz, Chiapas, Quintana Roo, Oaxaca, Morelos and Yucatán. The analysis per age groups and gender revealed that, in most age groups, the incidence was higher in the male population. The most number of cases was identified in spring and summer; a direct relationship between the environmental temperature increase and the number of new cases was identified. The analysis showed that the rate of Chagas disease increased presumably due to state programmes; the search for new cases has expanded and we speculate that the disease is associated with occupational activities. These results summarise and recall how important it is to implement the monitoring of Chagas disease mainly in south states of the Mexican Republic in order to implement strategies to control this disease.

Treatment of platelet concentrates and plasma with riboflavin and UV light: Impact in bacterial reduction.

OBJECTIVES: Transfusion of hemocomponents is essential for clinical and surgical procedures and therefore their safety has increased. An option for pathogen reduction includes the combination of riboflavin and UV light. To our knowledge, there are no studies in Latin America that demonstrate the effectiveness of the pathogen reduction in hemocomponents. The objective of this work was to evaluate the efficiency of a pathogens reduction system in platelets concentrates (PC) and plasma. MATERIALS AND METHODS: PC and plasma were contaminated with Escherichia coli, Klebsiella pneumoniae, Streptococcus pyogenes and Staphylococcus epidermidis at 104 to 106 CFU and subjected to bacterial reduction. After bacterial reduction, hemocomponents were subjected to cultivation of surviving bacteria by automated method and classical colonies quantification. Additionally, quality control testing was performed in order to confirm the integrity of platelets and coagulation laboratory values in plasma before and after bacterial reduction. RESULTS: The bacterial death in PC/plasma was expressed by Logarithmic Reduction Value as follows: for both strains (E. coli and S. pyogenes) 4/4, 5/5 and 6/6; for K. pneumoniae 2.54/2.23, 2.94/2.22 and 3.44/2.98, for S. epidermidis 4/4, 3.11/5 and 3.23/4.19, for 104, 105 and 106 CFU, respectively. In PC and plasma, platelet count, pH (at 22°C), activated partial thromboplastin time (aPTT), prothrombin time (PT), fibrinogen, factor VIII and total proteins (TP) were slightly modified. CONCLUSIONS: UV light with riboflavin is able to reduce an important number of pathogens in hemocomponents; however, the bacterial reduction is influenced by the nature and quantity of the pathogen.

External quality control program in screening for infectious diseases at blood banks in Mexico.

INTRODUCTION: Quality control for the detection of infectious markers in blood banks is a necessary activity to ensure the accuracy of donor screening results. Considering that in Mexico blood safety is one of the goals of the National Action Programs, it is essential to evaluate banks through an External Quality Control Program. OBJECTIVE: To analyze one of the evaluations that showed the greatest participation (2014-2/lot46) of banks in the Mexican Republic in the detection of transfusion-transmitted diseases. MATERIALS AND METHODS: A randomized panel of infectious markers of HIV, HCV, HBV, Treponema pallidum and Trypanosoma cruzi was manufactured under high quality standards. The evaluation criteria for each infectious marker were the identification of false positives and false negative results. Additionally, technologies used to detect infectious markers were requested for each bank. RESULTS: Of the 503 banks, only 374 participated in the evaluation. Technologies based on chemiluminescence, immunofluorescence and immunocolorimetry were used to detect viral markers. Even rapid tests for T. pallidum continue to be the methods of choice with 42%. Trypanosoma cruzi was 20% with fast techniques versus 80% with automated tests. Highest incidence of false positives was identified for T. pallidum and HBV, followed by T. cruzi, HIV and HCV. Fourteen (3.74%) false negatives results were identified for T. cruzi, followed by T. pallidum (n = 5/1.33%), HCV (n = 4/1.06) and HVB/HIV (n = 2/0.53%). CONCLUSION: False positive results identified for each infectious marker was considered high. This evidence will allow us to focus on areas of opportunity during serologic screening with greater emphasis on good laboratory practices.

HLA analysis of Mexican candidates for bone marrow transplantation and probability of finding compatible related donors.

INTRODUCTION: Oncohematological disorders are the main cause of morbidity in the Mexican population from 1 to 19 years old, where megakaryoblastic and promyelocitic leukemias are more frequent. Considering that the success of a transplant is multifactorial, the criterion of compatibility in the HLA system is crucial and even more so when the source of HSC is bone marrow. OBJECTIVE: To determine the frequency of the HLA genotype in Mexican candidates who require a bone marrow transplant from related donors and the probability to find donors. MATERIALS AND METHODS: One hundred twenty-six candidates for bone marrow transplant and related donors were tested for HLA class I (-A*, -B* alleles) and class II (-DRB1* allele) in intermediate-resolution, as the first phase in the choice of the possible donor. The criteria to identify donors were determined by antigen-matched in each HLA haplotype as follows: 4/6, 5/6 and 6/6 at the HLA-A*, HLA-B*, and HLA-DRB1* alleles. RESULTS: Of all the candidates analyzed, 57.93%, at least one bone marrow donor was identified; in 53 cases, no donor was found. The average size of the families was 4.79 ±â€¯1.06 members. A higher percentage of compatibility with grade 6/6 (31.6%) was identified with brothers, followed by sisters in 25.3%. The probability to find at least one compatible potential donor was 1.51 ±â€¯0.92 donors. CONCLUSION: In the first phase to select donors, Mexican patients studied in this work, have a compatible donor, however the grade of resolution test influenced in the probability identified.

Prevalence of bacterial contamination in platelet concentrates at the National Center of Blood Transfusion (Mexico).

OBJECTIVES: Most common bacterial sepsis associated with transfusion is caused by contaminated Platelet Concentrates (PC). The screening of PC to detect bacterial contamination is obligatory in Mexico, and it is carried out in quality control programs. In Mexico, the identification and molecular characterization of bacterial contaminants to detect contamination sources have not been implemented due to high costs; however, it is an actual current need. MATERIAL AND METHODS: One hundred PC were randomly selected and microbiologically analyzed. This sample size corresponds to 1% of the PC obtained by the National Center of Blood Transfusion (NCBT) in Mexico City according to the Official Mexican Standard NOM-253-SSA1-2012. Additionally, molecular biology tests were implemented in order to identify the possible contamination sources. RESULTS: Nine of the 100 PC analyzed (9%) showed bacterial contamination; analysis of the nucleotide sequences revealed the presence of characteristic microbiota from donor skin and soil. Diverse clonal relationship between the strains was identified in Staphylococcus epidermidis. CONCLUSION: Detection of contaminants associated with environmental and skin flora, shows the need to implement measures in the process of disinfecting skin at the site of phlebotomy and cleaning each of the areas involved in blood collection.

Central nervous system prophylaxis with intrathecal liposomal cytarabine in a subset of high-risk patients with diffuse large B-cell lymphoma receiving first line systemic therapy in a prospective trial.

The dissemination in the central nervous system (CNS) is an uncommon but fatal complication occurring in patients with diffuse large B-cell lymphoma (DLBCL). Standard prophylaxis has been demonstrated to reduce CNS relapse and improve survival rates. Intrathecal (IT) liposomal cytarabine allows maintaining elevated drug levels in the cerebrospinal fluid for an extended period of time. Data on the efficacy and safety of liposomal cytarabine as CNS prophylaxis in patients with DLBCL are still insufficient. The objective of the present study was to evaluate the effectiveness and safety of the prophylaxis with IT liposomal cytarabine in prevention of CNS relapse in high-risk patients with DLBCL who were included in a trial of first line systemic therapy with 6 cycles of dose-dense R-CHOP every 14 days. Twenty-four (18.6 %) out of 129 patients were identified to have risk factors for CNS involvement, defined as follows: >30 % bone marrow infiltration, testes infiltration, retroperitoneal mass ≥10 cm, Waldeyer ring, or bulky cervical nodes involvement. Liposomal cytarabine (50 mg) was administered by lumbar puncture the first day of the 1st, 2nd, and 6th cycle of R-CHOP14 scheme. Among 70 IT infusions, grade 3-4 adverse events reported were headache (one patient) and nausea/vomiting (one patient). With a median follow-up of 40.1 months, no CNS involvement by DLBCL was observed in any patient. In conclusion, IT liposomal cytarabine is safe, feasible, and effective for CNS prophylaxis, causing few associated risks and little discomfort to patients with DLBCL.

In vivo transfer of plasmid pRAS1 between Aeromonas salmonicida and Aeromonas hydrophila in artificially infected Cyprinus carpio L.

This study investigated the possible in vivo transfer of plasmid pRAS1 between Aeromonas salmonicida and A. hydrophila inhabiting two different organs of Cyprinus carpio L. To distinguish transconjugants from naturally occurring antibiotic resistant bacteria, twelve luminescent transposon-tagged A. hydrophila strains using mini Tn5luxCDABEKm2 transposon were generated. In conjugal transfer experiments, fish were conditioned with the donor bacteria and subsequently immersed in water containing the recipient strain. Bacteria were recovered from gills and intestines and isolated by growth on selective plates. Transconjugants were identified by their resistance to the pRAS1 encoded antimicrobials and by light emission. In vivo transfer frequencies ranged between 10(-3) and 10(-6) and were somewhat lower in intestines, compared to gills. Transfer frequencies were also smaller relative to those obtained in vitro. The minimal amount of donor and recipient bacteria needed to yield detectable transconjugants in vivo was 1 x 10(4) CFU mL(-1). Implications of this plasmid transfer in natural settings and its possible consequences to human health are discussed.

[C-reactive protein in differential diagnosis of primary thrombocytosis]. / La proteína C reactiva en el diagnóstico diferencial de la trombocitosis primaria.

BACKGROUND: The most potent stimulator for the hepatic synthesis of C-reactive protein is the interleukin-6. Also interleukin-6 is endowed with thrombopoietic activity, and its seric levels increases in most of secondary thrombocytosis whereas they remain normal in chronic myeloproliferative diseases or primary thrombocytosis. The aims of the study were verify the ability of quantitation of serum C-reactive protein in the differential diagnosis of primary thrombocytosis. METHODS: Serum samples from 89 patients with thrombocytosis (> 400 x 10(9)/1) and 54 normal controls were assayed for C-reactive protein. Patients with thrombocytosis were classified in primary thrombocytosis with 27 patients (chronic myeloproliferative disease with thrombocytosis) and secondary thrombocytosis (62 cases). RESULTS: The mean C-reactive protein serum levels observed in the 27 patients with primary thrombocytosis were 13 +/- 10 mg/l, superior to normal controls (7 +/- 5 mg/l; p < 0.01). In the secondary thrombocytosis group, C-reactive protein serum levels reached a mean value of 59 +/- 34 mg/l, clearly superior to control group and the primary thrombocytosis group (p < 0.0001). No patients in primary thrombocytosis group reached a C-reactive protein value > 40 mg/l, versus 65% of patients in secondary thrombocytosis group. A normal value occurred in 67% cases of primary thrombocytosis group, but also in 17% cases of secondary thrombocytosis group. CONCLUSIONS: Quantitation of C-reactive protein could thus prove useful in the differential diagnosis between primary and secondary thrombocytosis.

Sweet's syndrome during the chronic phase of chronic myeloid leukaemia.

We report the case of a 52 year-old male in the chronic phase of chronic myeloid leukaemia, with Philadelphia chromosome due to t(9;22) in the karyotype. He was treated with courses of busulfan and hydroxyurea. Fourteen months after initial presentation, the patient developed fever, non-productive cough, maculonodular violaceous painful skin lesions and bilateral pulmonary infiltrates visible on a chest roentgenogram. Laboratory data, repeated bone marrow aspiration and biopsy and karyotype analysis showed findings similar to those of the initial diagnosis. A biopsy taken from one of the trunk lesions was consistent with Sweet's syndrome. Oral methylprednisolone therapy was initiated at doses of 64 mg daily, and the skin lesions and fever were rapidly resolved. When we reduced the steroid dose, skin lesions and fever recurred. Two further courses of steroid therapy were given with similar results. Finally we treated him with naproxen (750 mg daily for 1 month) with a rapid and stable response. This drug should be considered as an alternative treatment for patients with Sweet's syndrome not responding to corticosteroids or for immunocompromised hosts.