Gram-Negative ESKAPE Bacteria Surveillance in COVID-19 Pandemic Exposes High-Risk Sequence Types of Acinetobacter baumannii MDR in a Tertiary Care Hospital.

The interruption of bacteriological surveillance due to the COVID-19 pandemic brought serious consequences, such as the collapse of health systems and the possible increase in antimicrobial resistance. Therefore, it is necessary to know the rate of resistance and its associated mechanisms in bacteria causing hospital infections during the pandemic. The aim of this work was to show the phenotypic and molecular characteristics of antimicrobial resistance in ESKAPE bacteria in a Mexican tertiary care hospital in the second and third years of the pandemic. For this purpose, during 2021 and 2022, two hundred unduplicated strains of the ESKAPE group (Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) were collected from various clinical sources and categorized by resistance according to the CLSI. An analysis of variance (ANOVA) complemented by the Tukey test was performed to search for changes in antimicrobial susceptibility profiles during the study period. Finally, the mechanisms of resistance involved in carbapenem resistance were analyzed, and the search for efflux pumps and high-risk sequence types in A. baumannii was performed by multilocus analysis (MLST). The results showed no changes in K. pneumoniae resistance during the period analyzed. Decreases in quinolone resistance were identified in E. coli (p = 0.039) and P. aeruginosa (p = 0.03). Interestingly, A. baumannii showed increases in resistance to penicillins (p = 0.004), aminoglycosides (p < 0.001, p = 0.027), carbapenems (p = 0.027), and folate inhibitors (p = 0.001). Several genes involved in carbapenem resistance were identified (blaNDM, blaVIM, blaOXA, blaKPC, blaOXA-40, and blaOXA-48) with a predominance of blaOXA-40 and the adeABCRS efflux pump in A. baumannii. Finally, MLST analysis revealed the presence of globally distributed sequence types (ST369 and ST758) related to hospital outbreaks in other parts of the world. The results presented demonstrate that the ESKAPE group has played an important role during the COVID-19 pandemic as nosocomial antibiotic-resistant pathogens and in particular A. baumannii MDR as a potential reservoir of resistance genes. The implications of the increases in antimicrobial resistance in pathogens of the ESKAPE group and mainly in A. baumannii during the COVID-19 pandemic are analyzed and discussed.

Neutralizing Antibodies against SARS-CoV-2: Importance of Comorbidities in Health Personnel against Reinfections.

One of the priority lines of action to contain the SARS-CoV-2 pandemic was vaccination programs for healthcare workers. However, with the emergence of highly contagious strains, such as the Omicron variant, it was necessary to know the serological status of health personnel to make decisions for the application of reinforcements. The aim of this work was to determine the seroprevalence against SARS-CoV-2 in healthcare workers in a Mexican hospital after six months of the administration of the Pfizer-BioNTech vaccine (two doses, 4 weeks apart) and to investigate the association between comorbidities, response to the vaccine, and reinfections. Neutralizing antibodies against SARS-CoV-2 were determined using ELISA assays for 262 employees of Hospital Juárez de México with and without a history of COVID-19. A beta regression analysis was performed to study the associated comorbidities and their relationship with the levels of antibodies against SARS-CoV-2. Finally, an epidemiological follow-up was carried out to detect reinfections in this population. A significant difference in SARS-CoV-2 seroprevalence was observed in workers with a history of COVID-19 prior to vaccination compared to those without a history of the disease (MD: 0.961 and SD: 0.049; <0.001). Beta regression showed that workers with a history of COVID-19 have greater protection compared to those without a history of the infection. Neutralizing antibodies were found to be decreased in alcoholic and diabetic subjects (80.1%). Notably, eight cases of Omicron reinfections were identified, and gender and obesity were associated with the presence of reinfections (6.41 OR; 95% BCa CI: 1.15, 105.0). The response to the vaccine was influenced by the history of SARS-CoV-2 infection and associated comorbidities. The above highlights the importance of prioritizing this segment of the population for reinforcements in periods of less than one year to guarantee their effectiveness against new variants.

COVID-19 Outbreak during Summer Courses at an Elementary School.

Due to the COVID-19 emergency, face-to-face classes were suspended. After the vaccination of teachers and to mitigate educational backwardness, the schools have begun to reopen with protocols established by the government. Here, we investigated the COVID-19 outbreak in summer courses during the reopening of a private elementary school in July 2021. We report confirmed cases of COVID-19 in staff members, students, and their families. A total community of 290 people was part of this study, and we built the contact network. The clinical features of all cases are described. We used the methodology of cases and contacts. The index case was identified by epidemiological tracking, and containment measures were activated, as well as further infection chains in the setting. We estimate the attack rate for staff members at 15.68% (95% CI 7.0-28.6), students at 12.24% (95% CI 4.6-24.8), and family members at 2.6% (95% CI 0.8-6.0). An incubation period of 48-72 h was determined. A student-teacher-student-family transmission sequence was identified. The area where the infection was identified was the school swimming pool, an area where face masks are not worn or, in some cases, inadequately used. Finally, we continue with intermittent staff testing and early detection actions, reinforcing prevention measures, environmental control, cleaning, and educational interventions with students regarding the implementation of preventive measures through classes led by school health staff.

Disinfection efficacy of ozone on ESKAPE bacteria biofilms: Potential use in difficult-to-access medical devices.

BACKGROUND: Medical devices can be reservoirs of multidrug-resistant bacteria that may be involved in the acquisition of infections since bacteria with the ability to form biofilms that are difficult to eradicate, mainly in mechanical ventilators. The aim of this work was to evaluate the efficacy of O3 against biofilms of bacteria ESKAPE group through disinfection studies. METHODS: The formation of biofilms of ESKAPE group bacteria was induced in vitro. O3 was injected at different exposure times at a constant dose of 600 mg/h. The recovery of surviving bacteria after O3 treatment was assessed by bacterial counts and biofilm disruption was analyzed. Finally, the viability and integrity of biofilms after O3 treatment was determined by confocal laser scanning microscopy (CLSM). RESULTS: O3 showed bactericidal activity on biofilms from 12 min/7.68 ppm for A. baumannii and C. freundii. P. aeruginosa, K. pneumoniae and S. aureus were killed after 15 min/9.60 ppm. Correlation analyses showed inversely proportional relationships between the variables "disruption versus O3". CLSM revealed that death was time-dependent of biofilms upon O3 exposure. Orthogonal plane analysis showed that bacteria located in the outer region of the biofilms were the ones that initially suffered damage from O3 exposure. CONCLUSIONS: Our findings suggest that this method could be an alternative for the disinfection in mechanical ventilators colonized by bacteria biofilm forming.

Epidemiology of the first seven years of national surveillance of amoebic liver abscesses in Mexico.

The epidemiological behaviour of the main extraintestinal complication due to E. histolytica (amoebic liver abscess, ALA) has been little explored in developing countries. Since Mexico meets the characteristics to be considered as endemic, the aim of this work was to analyze the national surveillance data (seven years) of ALA issued by the General Directorate of Epidemiology. An analysis of cases and incidence of ALA (2014-2020) was performed in the annual reports issued by the GDE in Mexico. Cases and incidence of ALA were classified by year, incidence, age group, sex and seasons. Geographical distribution map for the whole country of ALA was constructed. The cases and mean incidence of ALA did not shown significant variation during the study period. Of the total cases accumulated, Sonora, Sinaloa, Nayarit, Colima and Zacatecas states showed the most incidence by ALA. Male sex of 24-44 years old showed higher ALA cases. No temporal behaviour was identified between the ALA cases. In Mexico, the incidence of ALA remains unchanged, however, it should not be underestimated since the monitoring programs for the search for new cases have not yet been implemented mainly in endemic states. These results summarize the priority in the national ALA report.

ESKAPE bacteria characterization reveals the presence of Acinetobacter baumannii and Pseudomonas aeruginosa outbreaks in COVID-19/VAP patients.

INTRODUCTION: A decrease of detection of outbreaks by multidrug-resistant bacteria in critical areas has been reduced due to COVID-19 pandemic. Therefore, molecular epidemiological surveillance should be a primary tool to reveal associations not evident by classical epidemiology. The aim of this work was to demonstrate the presence of hidden outbreaks in the first wave of the COVID-19 pandemic and to associate their possible origin. METHODS: A population of 96 COVID-19 patients was included in the study (April to June 2020) from Hospital Juárez de México. Genetic identification and antimicrobial susceptibility testing of VAP causative agents isolated from COVID-19 patients was performed. Resistance phenotypes were confirmed by PCR. Clonal association of isolates was performed by analysis of intergenic regions obtained. Finally, the association of clonal cases of VAP patients was performed by timelines. RESULTS: ESKAPE and non-ESKAPE bacteria were identified as causative agents of VAP. ESKAPE bacteria were classified as MDR and XDR. Only A. baumannii and P. aeruginosa were identified as clonally distributed in 13 COVID-19/VAP patients. Time analysis showed that cross-transmission existed between patients and care areas. CONCLUSIONS: Acinetobacter baumannii and Pseudomonas aeruginosa were involved in outbreaks non-detected in COVID-19/VAP patients in the first wave of COVID-19 pandemic.

Trends in Gliosis in Obesity, and the Role of Antioxidants as a Therapeutic Alternative.

Obesity remains a global health problem. Chronic low-grade inflammation in this pathology has been related to comorbidities such as cognitive alterations that, in the long term, can lead to neurodegenerative diseases. Neuroinflammation or gliosis in patients with obesity and type 2 diabetes mellitus has been related to the effect of adipokines, high lipid levels and glucose, which increase the production of free radicals. Cerebral gliosis can be a risk factor for developing neurodegenerative diseases, and antioxidants could be an alternative for the prevention and treatment of neural comorbidities in obese patients. AIM: Identify the immunological and oxidative stress mechanisms that produce gliosis in patients with obesity and propose antioxidants as an alternative to reducing neuroinflammation. METHOD: Advanced searches were performed in scientific databases: PubMed, ProQuest, EBSCO, and the Science Citation index for research on the physiopathology of gliosis in obese patients and for the possible role of antioxidants in its management. CONCLUSION: Patients with obesity can develop neuroinflammation, conditioned by various adipokines, excess lipids and glucose, which results in an increase in free radicals that must be neutralized with antioxidants to reduce gliosis and the risk of long-term neurodegeneration.

Mechanical complications of weekly care and maintenance versus once every 10 days of the peripherally inserted central catheter line insertion site in newborns: A propensity score-matched cohort study in Mexico.

PURPOSE: To evaluate the mechanical complications of weekly care and maintenance versus once every 10 days of the peripherally inserted central catheter (PICC) line insertion site versus once every 10 days in newborns. DESIGN AND METHODS: Prospective propensity score matched cohort study. Care and maintenance of the PICC line insertion site were performed on days 7 and 10 during January 2018 to December 2019. To compare mechanical complications, propensity score matching was performed. Propensity scores were used to determine the relative risks and hazard ratios by using logistic regressions with log-link function and Cox regressions, respectively. RESULTS: We included 175 newborns hospitalized in the neonatal intensive care unit (NICU) who underwent insertion of a PICC line. Ninety-six received weekly care and maintenance, and 79 received care and maintenance every 10 days. Weekly care and maintenance were associated with more breakage (RR 1.98, 95% CI 1.68-2.34); occlusions (RR 0.81, 95% CI 0.46-1.42) and accidental withdrawals (RR 1.31, 95% CI 0.93-1.84) were not different between care and maintenance every 7 and 10 days. A survival analysis was performed, showing that weekly care and maintenance are a risk factor for removal for mechanical complications (HR 7.61, 95% CI 3.05-19.01). CONCLUSION: We concluded that care and maintenance of the PICC in newborns every 10 days have fewer complications than when performing care and maintenance every 7 days. PRACTICE IMPLICATIONS: Newborns requiring intravenous therapy will benefit from care and maintenance every 10 days, and this practice could potentially spread to other NICUs.

Epidemiological and Clinical Characteristics of Hospitalized Pediatric Patients with SARS-CoV-2 Infection in Mexico City, Mexico.

Background: Evidence from across the world suggests that the pediatric population shows different clinical manifestations and has a lower risk of severe presentation of SARS-CoV-2 infection compared to adults. However, Mexico has one of the highest mortality rates in the pediatric population due to SARS-CoV-2 infection. Therefore, our objective was to explore the epidemiological and clinical characteristics associated with a positive confirmatory test in the Mexican pediatric population admitted to a tertiary care hospital in Mexico City. Methods: Clinical, imaging and laboratory data were retrospectively collected from 121 children hospitalized during the period from March 4th, 2020, to August 8th, 2021. The patients were identified as suspicious cases according to the guidelines of the General Directorate of Epidemiology of Mexico. Real-time polymerase chain reaction (RT-PCR) tests were used to confirm SARS-CoV-2 infection. Categorical variables were compared using the Chi-square test, and propensity score matching was performed to determine univariate and multivariate odds ratios of the population regarding a positive vs. negative SARS-CoV-2 result. Results: Of the 121 children, 36 had laboratory-confirmed SARS-CoV-2 infection. The main risk for SARS-CoV-2-associated pediatric hospitalization was contact with a family member with SARS-CoV-2. It was also found that fever and fatigue were statistically significantly associated with a positive SARS-CoV-2 test in multivariate models. Clinical and laboratory data in this Mexican hospitalized pediatric cohort differ from other reports worldwide; the mortality rate (1.6%) of the population studied was higher than that seen in reports from other countries. Conclusion: Our study found that fever and fatigue at hospital presentation as well as an antecedent exposure to a family member with SARS-CoV-2 infection were important risk factors for SARS-CoV-2 positivity in children at hospital admission.

Interaction of metabolic dysfunction-associated fatty liver disease and nonalcoholic fatty liver disease with advanced fibrosis in the death and intubation of patients hospitalized with coronavirus disease 2019.

Patients with pre-existing liver diseases are considered to have an increased risk of morbidity and mortality from any type of infection, including viruses. The aim of this work was to explore the implications of metabolic dysfunction-associated fatty liver disease (MAFLD) and nonalcoholic fatty liver disease (NAFLD) definitions in coronavirus disease 2019 (COVID-19) and to study the interaction between advanced fibrosis (AF) and each of these diseases in the death and intubation of patients hospitalized with COVID-19. We performed a retrospective study with 359 patients hospitalized with confirmed COVID-19 infection in a tertiary referral hospital who were admitted between April and June 2020. A multivariate Cox model was performed regarding the interaction of AF with MAFLD and NAFLD in the mortality and intubation of patients with COVID-19. The death rate was statistically significantly higher in the MAFLD group compared to the control group (55% vs. 38.3%, p = 0.02). No significant difference was seen in the death rate between the NAFLD and control group. The MAFLD (44.09% vs. 20%, p = 0.001) and NAFLD (40.51% vs. 20%, p = 0.01) groups had statistically significantly higher intubation rates than the control group. A statistically significant interaction between NAFLD and AF was associated with an increase in mortality (p = 0.01), while a statistically significant interaction between MAFLD and AF was associated with an increased risk of mortality (p = 0.006) and intubation (p = 0.049). In the case of patients hospitalized with COVID-19, our results indicate that the death rate was higher in the MAFLD group but not the NAFLD group compared to that in the control group. The intubation rates were higher in the NAFLD and MAFLD groups compared to rates in the control group, suggesting that both could be associated with COVID-19 severity. In addition, we found interactions between AF with MAFLD and NAFLD.

Massive sequencing of the V3-V4 hypervariable region of bronchoalveolar lavage from patients with COVID-19 and VAP reveals the collapse of the pulmonary microbiota.

Background. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic is a predisposing factor for the development of healthcare-associated infections, of which ventilator-associated pneumonia (VAP) is one.Hypothesis. VAP is caused by ESKAPE bacteria and other pathogens not detected by microbiological culture.Aim. To elucidate the bacterial pathogens of severe coronavirus disease 2019 (COVID-19) and VAP patients by massive sequencing and to predict their degree of relationship with the age and sex of the patients.Methods. Analysis of ribosomal libraries of the V3-V4 hypervariable region obtained by Illumina sequencing of bronchoalveolar lavages from COVID-19 and VAP (first wave) patients from Hospital Juárez de México.Results. Acinetobacter and Pseudomonas were the main bacterial genera in the bronchoalveolar lavages (BALs) analysed. Other members of the ESKAPE group, such as Enterococcus and Klebsiella, were also identified. Taxonomic composition per patient showed that non-ESKAPE genera were present with significant relative abundances, such as Prevotella, Stenotrophomas, Enterococcus, Mycoplasma, Serratia and Corynebacterium. Kruskal-Wallis analysis proved that VAP acquisition is an adverse event that is not influenced by the sex and age of COVID-19 patients.Discussion. Metagenomic findings in COVID-19/VAP patients highlight the importance of implementing comprehensive microbiological diagnostics by including alternative tools for the detection of the causal agents of healthcare-associated infections (HAIs).Conclusions. Timely identification of bacteria 'not sought' in diagnostic bacteriology laboratories will allow specific and targeted treatments. Implications for the restricted diagnosis of VAP causative agents in COVID-19 patients and the presence of pathogens not detected by classical microbiology are analysed and discussed.

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.

Impact of the modification of a cleaning and disinfection method of mechanical ventilators of COVID-19 patients and ventilator-associated pneumonia: One year of experience.

BACKGROUND: Mechanical ventilators are essential biomedical devices for the respiratory support of patients with SARS-CoV-2 infection. These devices can be transmitters of bacterial pathogens. Therefore, it is necessary to implement effective disinfection procedures. The aim of this work was to show the impact of the modification of a cleaning and disinfection method of mechanical ventilators of patients with SARS-CoV-2 and ventilator-associated pneumonia. METHODS: A total of 338 mechanical ventilators of patients infected with SARS-CoV-2 and ESKAPE bacteria were divided in two groups. Group A and B were subjected to cleaning and disinfection with superoxidation solution-Cl/enzymatic detergent and isopropyl alcohol, respectively. Both groups were cultured for the detection of ESKAPE bacteria. The isolates were subjected to tests for identification, resistance, adherence, and genomic typing. RESULTS: Contamination rates of 21.6% (n = 36) were identified in group A. The inspiratory limb was the circuit involved in most cases of postdisinfection contamination. Acinetobacter baumanni, Pseudomonas aeruginosa, and multi-resistant Klebsiella pneumoniae were the pathogens involved in the contamination cases. The pathogens were highly adherent and in the case of A. baumanni, clonal dispersion was detected in 14 ventilators. Disinfection with enzymatic detergents allows a 100% reduction in contamination rates. CONCLUSIONS: The implementation of cleaning and disinfection with enzymatic detergents/isopropyl alcohol of mechanical ventilators of patients with SARS-CoV-2 and ESKAPE bacteria had a positive impact on postdisinfection microbial contamination rates.

Klebsiella pneumoniae blaNDM-1 carrying a class 1 integron causing a hospital outbreak in a Mexican attention center.

INTRODUCTION: Infections acquired in hospitals are the cause of high morbidity and mortality and with the emergence of resistant bacteria, the problem is greater. The aim of this work was to determine the genetic characteristics and timeline of Klebsiella pneumoniae blaNDM-1 carrying a class 1 integron involved in an intrahospital outbreak. METHODOLOGY: Investigation was made from the first detection of K. pneumoniae blaNDM-1, strain "466", and the last clone "423". 16S rRNA gene analysis showed that 466 strain and clones were related to K. pneumoniae. Extended-spectrum ß-lactamases (ESBL) was detected according to the Clinical and Laboratory Standards Institute (CLSI) and real time-PCR. Typing of K. pneumoniae blaNDM-1 strains was carried by ERIC-PCR and sequencing the variable region of the integrons were performed. RESULTS: A cluster of six resistant isolates of K. pneumoniae blaNDM-1 was detected in intensive care unit (ICU), internal medicine (IM) and orthopedics (OT). Timeline revealed that the first bacterial identification was in ICU and the last clone in OT service. The array genetic of variable region was "IntI/aadA5-drfA17/qacEΔ1-Sul1". CONCLUSIONS: The evidences highlight the importance of the epidemiological surveillance of Extended-spectrum ß-lactamases (ESBL) strains, as well as the need for molecular epidemiological studies to identify the routes of transmission and the contamination sources within health personnel.

Clonal dispersion of Acinetobacter baumannii in an intensive care unit designed to patients COVID-19.

INTRODUCTION: SARS-CoV2 pandemic marks the need to pay attention to bacterial pathogens that can complicate the hospital stay of patients in the intensive care unit (ICU). ESKAPE bacteria which includes Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae are considered the most important, because of their close relationship with the development of ventilator-associated pneumonia (VAP). The aim of this work was to identify and characterize ESKAPE bacteria and to detect their possible clonal spread in medical devices, patients, and medical personnel of the ICU for COVID-19 patients of the Hospital Juarez de Mexico. METHODOLOGY: Genetic identification of ESKAPE bacteria was performed by analyzing the 16S rRNA gene. Resistance assays were performed according to the CLSI guidelines. Assembly of AdeABCRS operon and inhibition assays of pumps efflux in Acinetobacter baumannii isolates were performed. Associated gene involved in biofilm formation (icaA) was performed in isolates belonging to the Staphylococcus genus. Finally, typing by ERIC-PCR and characterization of mobile genetic element SCCmec were done. RESULTS: Heterogeneous distribution of ESKAPE and non-ESKAPE bacteria was detected in various medical devices, patients, and medical personnel. Acinetobacter baumannii and Staphylococcus aureus were the predominant ESKAPE members. The analysis of intergenic regions revealed an important clonal distribution of A. baumannii (AdeABCRS+). Genotyping of SCCmec mobile genetic elements and the icaA gene showed that there is no clonal distribution of S. aureus. CONCLUSIONS: Clonal spread of A. baumannii (AdeABCRS+) highlights the importance of adopting good practices for equipment disinfection, surfaces and management of COVID-19 patients.

Catecholamine levels and gene expression of their receptors in tissues of adults with osteosarcoma.

AIM: The purpose of this work was to identify and measure catecholamines, their metabolites, and the gene expression of catecholamine receptors in osteosarcoma tissue. MATERIALS AND METHODS: The levels of 3,4-dihydroxyphenylacetic acid, norepinephrine, serotonin, and 5-hydroxyindoleacetic acid in cancer tissue and in adjacent and non-oncological bone tissue were analysed by high-performance liquid chromatography, and the gene expression of catecholamine receptors and of dopamine ß-hydroxylase, monoaminoxidase, ki67, and Runx2 in the osteosarcoma tissue, tissue adjacent to the tumour, non-oncological bone, and human brain tissue was analysed by RT-PCR. RESULTS: We found significantly higher levels of 3,4-dihydroxyphenylacetic acid and norepinephrine in the cancer sample than in adjacent and non-oncological bone. We found that ß-adrenergic receptors and dopaminergic receptors, dopamine ß-hydroxylase, ki67, Runx2, and serotonergic receptor gene expression were significantly higher in tumour tissue than in adjacent and non-oncological bone. CONCLUSION: Catecholamines and their receptors could be potential molecular markers for osteosarcoma progression.

Genetic and phenotypic determinants of resistance to antibiotics in Aeromonas spp., strains isolated from pediatric patients.

INTRODUCTION: Intestinal and extraintestinal infections by Aeromonas spp., remain controversial, due to the existence of healthy carriers of Aeromonas spp. In children under five years old, the diarrhea of infectious origin constitutes the second cause of mortality and remains a major concern for public health. The aim of this work was to detect the pheno/genotype of ß-lactamases and class 1 integrons in Aeromonas spp., strains isolated from pediatric patients in a tertiary referral hospital in Mexico. METHODOLOGY: Sixty-six strains of Aeromonas spp., were isolated from clinical samples of pediatric origin and were identified by RFLP-PCR 16S rRNA. Resistance phenotype according to CLSI, genetic and phenotypic detection of extended-spectrum ß-lactamases (ESBL) and metallo-b-lactamases (MBL) was performed. Finally, characterization of class 1 integrons was performed. RESULTS: Aeromonas spp., strains of diarrheic origin were more predominant. A wide heterogeneity was detected, where A. caviae was the predominant specie. Second-generation cephalosporins, fluoroquinolones, and nitrofurans had best antimicrobial activity; moreover, antibiotics of the ß-lactamic and lincosamides families showed lower inhibitory activity. Phenotypically, prevalences of 4.55% and 3.03% were detected for MBL (intestinal origin) and ESBL (extraintestinal origin), respectively. blaIMIS-cphA and blaTEM-1 genes, and nineteen class 1 integrons carrying two variants of cassettes corresponding to adenylyl transferases (aadA), and dihydrofolate reductases (dfrA). Monogenic array with aadA1 cassette was predominantly. CONCLUSIONS: ESBL and class 1 integrons, in Aeromonas collected from pediatric patients, determines a major detection challenge for the clinical microbiology laboratory and represents a remarkable epidemiological risk of nosocomial spread of multidrug-resistant determinants.

Disinfection of N95 masks artificially contaminated with SARS-CoV-2 and ESKAPE bacteria using hydrogen peroxide plasma: Impact on the reutilization of disposable devices.

INTRODUCTION: One of the serious consequences of the SARS-CoV-2 pandemic is the shortage of protective equipment for health personnel. N95 masks are considered one of the essential protective equipment in the management of patients with COVID-19. The shortage of N95 masks implies potential health risks for health personnel and significant economic losses for the health institution. The objective of this work was to investigate the disinfection of N95 masks artificially contaminated with SARS-CoV-2 and ESKAPE bacteria by using hydrogen peroxide plasma. MATERIAL AND METHODS: We examined the disinfection capacity of hydrogen peroxide plasma against the SARS-CoV-2 and 2 members of the ESKAPE bacteria (Acinetobacter baumannii and Staphylococcus aureus) through a study of artificial contamination in situ of N95 masks. Amplification of specific genes by real-time reverse transcription polymerase chain reaction of SARS-CoV-2 and microbiological culture of ESKAPE bacteria was performed before and after the disinfection process. RESULTS: SARS-CoV-2 was not detected in all assays using 5 different concentrations of the virus, and A baumannii and S aureus were not cultivable with inoculums of 102 to 106 CFU after disinfection tests of N95 masks with hydrogen peroxide plasma. CONCLUSION: Disinfection of N95 masks by using the hydrogen peroxide plasma technology can be an alternative for their reuse in a shortage situation. Implications for the use of disinfection technologies of N95 masks and the safety of health personnel are discussed.

Commensal and virulent Escherichia coli strains of vaginal origin are reservoirs of resistance cassettes in class 1 integrons.

INTRODUCTION: Antimicrobial resistance in Escherichia coli, one of the causal agents of aerobic vaginitis, leads to the persistence of the infection. The investigation of integrons acquires relevance, since they are elements that are responsible for the acquisition of resistance to antibiotics. The aim of this work was to describe the structural diversity of class 1 integrons in virulent and commensal strains of E. coli isolated from patients with vaginal infection. METHODOLOGY: Ninety-two strains of E. coli were isolated from patients with aerobic vaginitis. Resistance profile against 19 antibiotics and class 1 integrons were detected by PCR. The identity and arrangement of cassettes was determined by sequencing. ERIC-PCR assays were carried out in strains with identical arrays. Finally, genotyping by Clermont algorithm and serotyping were performed. Seventeen strains showed integrons located in plasmids. RESULTS: Ten different gene cassette arrays were identified in 30 strains of E. coli. Cassettes corresponding to genes coding for adenylyltransferases (aadA), dihydrofolate reductases (dfrA), and oxacillinases (blaOXA) were detected. Array dfrA17-aadA5 was predominantly prevalent over the other arrays identified. Phylogenetic group A was the most predominant, followed by group B2 and D. CONCLUSIONS: This study demonstrates the presence of E. coli of vaginal origin carrying class 1 integrons, which are main genetic elements of capture of resistance genes, with the possibility of capturing new resistance cassettes. These evidences should serve for the modification of protocols in the diagnosis and treatment of aerobic vaginitis, and the development of policies for the rational use of antimicrobials.

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.