Bacterial incidence and drug resistance from pathogens recovered from blood, cerebrospinal and pleural fluids in 2019-2020. Results of the Invifar network.

Background: Antimicrobial resistance is a global concern. Analysis of sterile fluids is essential because microorganisms are defined as significant in most cases. Blood, cerebrospinal, and pleural fluids are frequently received in the microbiology lab because they are associated with considerable rates of morbi-mortality. Knowledge of epidemiology in these samples is needed to choose proper empirical treatments due to the importance of reducing selection pressure. Methods: We used retrospective laboratory data of blood, CSF, and pleural fluid collected from patients in Mexico between 2019 and 2020. Each laboratory identified the strains and tested susceptibility using its routine methods. For Streptococcus pneumoniae, a comparative analysis was performed with data from the broth microdilution method. Results: Forty-five centers participated in the study, with 30,746 clinical isolates from blood, 2,429 from pleural fluid, and 2,275 from CSF. For blood and CSF, Staphylococcus epidermidis was the most frequent. For blood, among gram negatives, the most frequent was Escherichia coli. Among Enterobacterales, 9.8% of K. pneumoniae were carbapenem-resistant. For S. pneumoniae, similar resistance percentages were observed for levofloxacin, cefotaxime, and vancomycin. For CSF, the most frequent gram-negative was E. coli. In Acinetobacter baumannii, carbapenem resistance was 71.4%. The most frequent species detected for pleural fluid was E. coli; in A. baumannii, carbapenem resistance was 96.3%. Conclusion: Gram-negative bacteria, with E. coli most prevalent, are frequently recovered from CSF, blood, and pleural fluid. In S. pneumoniae, the routine, conventional methods showed good agreement in detecting resistance percentages for erythromycin, levofloxacin, and vancomycin.

One-step nested RT-PCR for COVID-19 detection: A flexible, locally developed test for SARS-CoV2 nucleic acid detection.

INTRODUCTION: Due to the coronavirus pandemic, identifying the infected individuals has become key to limiting its spread. Virus nucleic acid real-time RT-PCR testing has become the current standard diagnostic method but high demand could lead to shortages. Therefore, we propose a detection strategy using a one-step nested RT-PCR. METHODOLOGY: The nucleotide region in the ORF1ab gene that has the greatest differences between the human coronavirus and the bat coronavirus was selected. Primers were designed after that sequence. All diagnostic primers are species-specific since the 3´ end of the sequence differs from that of other species. A primer set also creates a synthetic positive control. Amplified products were seen in a 2.5% agarose gel, as well as in an SYBR Green-Based Real-Time RT-PCR. RESULTS: Amplification was achieved for the positive control and specific regions in both techniques. CONCLUSIONS: This new technique is flexible and easy to implement. It does not require a real-time thermocycler and can be interpreted in agarose gels, as well as adapted to quantify the viral genome. It has the advantage that if the coronavirus mutates in one of the key amplification nucleotides, at least one pair can still amplify, thanks to the four diagnostic primers.

Presence of Acute Chagas Disease Among Febrile Patients in the Western Coast of Mexico.

Chagas disease (ChD) is a parasitosis caused by the protozoan Trypanosoma cruzi (Tc). It is endemic to almost all Latin American countries, including the southern United States. The acute form of ChD and its actual incidence have rarely been described in Mexico, despite the extensive presence of favorable niches for its transmission. The objective of this study was to estimate the frequency of acute ChD in febrile patients at the central Pacific coast of Mexico. For this, we surveyed patients with persistent fever (5 to 10 days) in five hospitals at the Mexican states of Jalisco, Colima, and Nayarit in 2012. Samples were taken from a total of 485 patients to detect Tc in blood using the polymerase chain reaction (PCR) test and direct microscopic examination. Of these subjects, 10 were positive for PCR and none for microscopic examination (2% in 12 months). We adjusted this rate by the total people at risk in the area and obtained an incidence of 7.4/100,000 habs./year. The positive cases showed no association with sex, rural settlement, or pet ownership, only with the contact with Triatominae insects (odds ratio = 9.22 and confidence interval: 1.93-44.06). The clinical picture of positive patients showed an association with the diagnosis of lower respiratory tract infections. Meanwhile, only one fatal case showed the typical picture of acute fatal cardiomyopathy. The pulmonary manifestations of our patients suggest possible lung pathogenicity of Tc, which merits further investigation. Our findings differ markedly from the official reports for ChD. This difference suggests an underestimation of the disease. These findings urge the Mexican health authorities to implement more vigorous actions aimed at improving medical skills in the timely diagnosis of ChD, as well as to apply efficient preventive programs.

Respiratory viruses detected in Mexican children younger than 5 years old with community-acquired pneumonia: a national multicenter study.

BACKGROUND: Acute respiratory infections are the leading cause of mortality in children worldwide, especially in developing countries. Pneumonia accounts for 16% of all deaths of children under 5 years of age and was the cause of death of 935000 children in 2015. Despite its frequency and severity, information regarding its etiology is limited. The aim of this study was to identify respiratory viruses associated with community-acquired pneumonia (CAP) in children younger than 5 years old. METHODS: One thousand four hundred and four children younger than 5 years of age with a clinical and/or radiological diagnosis of CAP in 11 hospitals in Mexico were included. Nasal washes were collected, placed in viral medium, and frozen at -70°C until processing. The first 832 samples were processed using the multiplex Bio-Plex/Luminex system and the remaining 572 samples using the Anyplex multiplex RT-PCR. Clinical data regarding diagnosis, clinical signs and symptoms, radiographic pattern, and risk factors were obtained and recorded. RESULTS: Of the samples tested, 81.6% were positive for viruses. Respiratory syncytial virus (types A and B) was found in 23.7%, human enterovirus/rhinovirus in 16.6%, metapneumovirus in 5.7%, parainfluenza virus (types 1-4) in 5.5%, influenza virus (types A and B) in 3.6%, adenovirus in 2.2%, coronavirus (NL63, OC43, 229E, and HKU1) in 2.2%, and bocavirus in 0.4%. Co-infection with two or more viruses was present in 22.1%; 18.4% of the samples were negative. Using biomass for cooking, daycare attendance, absence of breastfeeding, and co-infections were found to be statistically significant risk factors for the presence of severe pneumonia. CONCLUSIONS: Respiratory syncytial virus (types A and B), human enterovirus/rhinovirus, and metapneumovirus were the respiratory viruses identified most frequently in children younger than 5 years old with CAP. Co-infection was present in an important proportion of the children.

Preclinical trial on the use of doxycycline for the treatment of adenocarcinoma of the duodenum.

Adenocarcinoma of the duodenum comprises 50-70% of duodenal tumors. There is an increase in extracellular matrix metalloproteinases in this disease and it has been suggested that they play an important role in the development and pathology. Therefore, new therapeutic recommendations based on inhibitors of these enzymes, such as doxycycline, are under investigation. The cytotoxic effect of doxycycline was evaluated in the HuTu-80 duodenal adenocarcinoma cell line and its antitumor effect was determined in an immunodeficient murine model. A 10-µM (4.4 µg/ml) concentration of doxycycline was capable of causing apoptosis in 90% of the culture cells. Doxycycline was also responsible for a decrease in tumor growth and an increase in the survival of the mice with HuTu-80-cell tumors. These results suggest that doxycycline is a potential cytotoxic and antitumor agent effective in the treatment of adenocarcinoma of the duodenum.

Histological changes caused by meclofenamic acid in androgen-independent prostate cancer tumors: evaluation in a mouse model.

Meclofenamic acid is a nonsteroidal anti-inflammatory drug that has shown therapeutic potential for different types of cancers, including androgen-independent prostate neoplasms. The antitumor effect of diverse nonsteroidal anti-inflammatory drugs has been shown to be accompanied by histological and molecular changes that are responsible for this beneficial effect. The objective of the present work was to analyze the histological changes caused by meclofenamic acid in androgen-independent prostate cancer. Tumors were created in a nude mouse model using PC3 cancerous human cells. Meclofenamic acid (10 mg/kg/day; experimental group, n=5) or saline solution (control group, n=5) was administered intraperitoneally for twenty days. Histological analysis was then carried out on the tumors, describing changes in the cellular architecture, fibrosis, and quantification of cellular proliferation and tumor vasculature. Meclofenamic acid causes histological changes that indicate less tumor aggression (less hypercellularity, fewer atypical mitoses, and fewer nuclear polymorphisms), an increase in fibrosis, and reduced cellular proliferation and tumor vascularity. Further studies are needed to evaluate the molecular changes that cause the beneficial and therapeutic effects of meclofenamic acid in androgen-independent prostate cancer.

Histological changes caused by meclofenamic acid in androgen independent prostate cancer tumors: evaluation in a mouse model

ABSTRACT Meclofenamic acid is a nonsteroidal anti-inflammatory drug that has shown therapeutic potential for different types of cancers, including androgen-independent prostate neoplasms. The antitumor effect of diverse nonsteroidal anti-inflammatory drugs has been shown to be accompanied by histological and molecular changes that are responsible for this beneficial effect. The objective of the present work was to analyze the histological changes caused by meclofenamic acid in androgen-independent prostate cancer. Tumors were created in a nude mouse model using PC3 cancerous human cells. Meclofenamic acid (10 mg/kg/day; experimental group, n=5) or saline solution (control group, n=5) was administered intraperitoneally for twenty days. Histological analysis was then carried out on the tumors, describing changes in the cellular architecture, fibrosis, and quantification of cellular proliferation and tumor vasculature. Meclofenamic acid causes histological changes that indicate less tumor aggression (less hypercellularity, fewer atypical mitoses, and fewer nuclear polymorphisms), an increase in fibrosis, and reduced cellular proliferation and tumor vascularity. Further studies are needed to evaluate the molecular changes that cause the beneficial and therapeutic effects of meclofenamic acid in androgen-independent prostate cancer.

Preclinical analysis of nonsteroidal anti-inflammatory drug usefulness for the simultaneous prevention of steatohepatitis, atherosclerosis and hyperlipidemia.

Nonalcoholic steatohepatitis (NASH) is currently one of the primary liver diseases. Recent studies have shown a clinical relation between NASH and atherosclerosis. There is much interest in these two diseases because they are both associated with great morbidity and mortality. Inflammation and the overexpression of COX-2 participate in the pathophysiology of the two diseases, and therefore simultaneous treatment is feasible. The role of the four NSAIDs, meclofenamate, mefenamate, flufenamate, and aspirin, was analyzed in a mouse model of NASH, as well as preclinical atherosclerosis induced by a high-fat diet (HFD). Six mouse groups were formed. Five of the groups were fed a high-fat diet for 6 months and one group was fed a standard diet, acting as the normality reference. Of the five groups fed a high-fat diet, four received a NSAID, each of them identified by the specific drug administered. One group received no treatment. Serum markers (cholesterol, triglycerides, ALT, and AST) and histologic changes in the aorta and liver were analyzed for the study. Aspirin significantly reduced the hepaticsteatosis. All the drugs significantly reduced the hepatic inflammatory infiltrate. In relation to atherosclerosis, there were significant reductions in all the study variables with the use of aspirin and flufenamate. The four medications were able to stop steatosis from progressing into steatohepatitis by reducing inflammation. However, aspirin was the most beneficial, simultaneously reducing steatosis, atherosclerosis, and serum cholesterol levels.

Association of Milk and Meat Consumption with the Development of Breast Cancer in a Western Mexican Population.

BACKGROUND: Breast cancer is a public health problem and it is the most common gynecologic neoplasia worldwide. The risk factors for its development are of both hereditary and environmental origin. Certain foods have been clearly associated with modifying the breast cancer risk. The aim of the present analysis was to evaluate the effects of cow's milk and meat consumption on the development of breast cancer in a population from Western Mexico (Colima). MATERIAL AND METHODS: We studied 97 patients presenting with a histopathologic diagnosis of breast cancer and 104 control individuals who did not present with the disease (Breast Imaging Report and Data System (BI-RADS) 1-2). 80% of the population belonged to a low socioeconomic stratum. The main clinical characteristics were analyzed along with the lifetime consumption of meat and milk. RESULTS: High milk consumption increased the breast cancer risk by 7.2 times (p = 0.008) whereas the consumption of meat was not significantly associated with the disease. CONCLUSIONS: High consumption of cow's milk was a risk factor for the development of breast cancer. Further studies are needed to evaluate the effects of dietary patterns on the development of breast cancer in diverse populations with ethnic, cultural, and economic differences.

Protective effect of doxycycline on germinal epithelial loss caused by a high-fat diet.

INTRODUCTION: A high-fat diet and male obesity are aspects associated with germinal epithelial alterations and male infertility. Some reports have shown that certain tetracyclines can protect the germinal epithelium from toxic drugs. The aim of the present study design was to evaluate the possible effect of doxycycline on testicular germ cells in individuals fed a Western diet (atherogenic), using a murine model. METHODS: Two groups of male mice (BALB/c) were fed a high-fat Western diet (HFD). One of these two groups was given doxycycline at a dose of 10 mg/kg/day (HFD+Dox). A third group was fed a standard rodent diet (SD group). After 6 months, the mice were euthanized and morphologic and histopathologic analyses were performed. RESULTS: Germinal epithelial height was similar between the SD group (54 µm) and the HFD+Dox group (53 µm) (p = 0.26), and it was significantly reduced in the HFD group (47 µm) (p = 0.0001). The degree of germinal epithelial loss (DGEL) was significantly lower in the SD (10) and HFD+Dox (12.5) groups than in the HFD group (30) (p = 0.0001 and =0.007, respectively). There were no differences in the DGEL between the SD and HFD+Dox groups (p = 0.42). CONCLUSIONS: Doxycycline administration was shown to prevent germinal epithelial loss in the testes of mice fed a high-fat diet. Future studies are necessary to evaluate the clinical usefulness of doxycycline or its analogs in persons with a habitual high-fat diet.

Detection of sequences from a potentially novel strain of cell fusing agent virus in Mexican Stegomyia (Aedes) aegypti mosquitoes.

Flaviviruses (FVs) are a very heterogeneous group of viruses that includes viruses capable of infecting insects and/or vertebrates. Different human-disease-causing FVs are disseminated by mosquitoes, and therefore, the search for FV in these insects has recently been proposed in order to evaluate their potential transmission in a given community. An entomological survey was carried out in Colima (the hyperendemic dengue fever transmission zone in Mexico) to collect culicidae in urban and wild areas. No human-pathogenic FVs were found, but sequences related to a potentially novel strain of cell fusing agent virus (CFAV) were detected in Stegomyia (Aedes) aegypti mosquitoes.

Polymorphism in the matrix metalloproteinase-2 gene promoter is associated with cervical neoplasm risk in Mexican women.

Matrix metalloproteinase-2 (MMP-2) is an enzyme with proteolytic activity on matrix proteins, and previous studies have revealed a strong association between the MMP-2 -1306C-->T polymorphism and the risk of several types of cancer. Our study looked at whether this polymorphism contributed to the development of cervical neoplasia by analyzing 54 patients with invasive squamous cell cervical cancer, 100 patients with cervical intraepithelial neoplasia, and 126 control subjects. The MMP-2 CC genotype was more frequent in the cancer patients when compared with the control group (OR 2.57; 95% CI 1.15-5.86). The association of cervical cancer with the CC genotype was more pronounced in women who had first coitus at an early age (OR 3.96; 95% CI 1.46-11.06). The CC genotype was associated with intraepithelial neoplasia only in women with first coitus at 19 years old or younger. The data suggest that the MMP-2 -1306C-->T polymorphism contributes to the development of squamous cell cervical cancer in the population studied, especially in women who had first coitus at an early age.