A bioinformatic approach to identify confirmed and probable CRISPR-Cas systems in the Acinetobacter calcoaceticus-Acinetobacter baumannii complex genomes.

Introduction: The Acinetobacter calcoaceticus-Acinetobacter baumannii complex, or Acb complex, consists of six species: Acinetobacter baumannii, Acinetobacter calcoaceticus, Acinetobacter nosocomialis, Acinetobacter pittii, Acinetobacter seifertii, and Acinetobacter lactucae. A. baumannii is the most clinically significant of these species and is frequently related to healthcare-associated infections (HCAIs). Clustered regularly interspaced short palindromic repeat (CRISPR) arrays and associated genes (cas) constitute bacterial adaptive immune systems and function as variable genetic elements. This study aimed to conduct a genomic analysis of Acb complex genomes available in databases to describe and characterize CRISPR systems and cas genes. Methods: Acb complex genomes available in the NCBI and BV-BRC databases, the identification and characterization of CRISPR-Cas systems were performed using CRISPRCasFinder, CRISPRminer, and CRISPRDetect. Sequence types (STs) were determined using the Oxford scheme and ribosomal multilocus sequence typing (rMLST). Prophages were identified using PHASTER and Prophage Hunter. Results: A total of 293 genomes representing six Acb species exhibited CRISPR-related sequences. These genomes originate from various sources, including clinical specimens, animals, medical devices, and environmental samples. Sequence typing identified 145 ribosomal multilocus sequence types (rSTs). CRISPR-Cas systems were confirmed in 26.3% of the genomes, classified as subtypes I-Fa, I-Fb and I-Fv. Probable CRISPR arrays and cas genes associated with CRISPR-Cas subtypes III-A, I-B, and III-B were also detected. Some of the CRISPR-Cas systems are associated with genomic regions related to Cap4 proteins, and toxin-antitoxin systems. Moreover, prophage sequences were prevalent in 68.9% of the genomes. Analysis revealed a connection between these prophages and CRISPR-Cas systems, indicating an ongoing arms race between the bacteria and their bacteriophages. Furthermore, proteins associated with anti-CRISPR systems, such as AcrF11 and AcrF7, were identified in the A. baumannii and A. pittii genomes. Discussion: This study elucidates CRISPR-Cas systems and defense mechanisms within the Acb complex, highlighting their diverse distribution and interactions with prophages and other genetic elements. This study also provides valuable insights into the evolution and adaptation of these microorganisms in various environments and clinical settings.

Intrauterine Transmission of Zika and Vertical Transfer of Neutralizing Antibodies Detected Immediately at Birth in Oaxaca, Mexico: An Analysis in the Context of Microcephaly.

Zika virus (ZIKV) can cause neurological issues in infants. To provide protection, neutralizing antibodies should be transferred from the mother to the infant. We conducted a study at the Hospital General de Pochutla, Oaxaca, Mexico. Samples were collected from mothers (blood and breast milk) and infants (saliva and dried blood spots) within the first 12 postnatal hours (December 2017 to February 2018) and tested for ZIKV total and neutralizing antibodies as well as ZIKV-PCR. Microcephaly was evaluated according to INTERGROWTH-21st standards. Maternal IgG seroprevalence was 28.4% with 10.4% active infection, while infant IgG seroprevalence was 5.5% with 2.4% active infection. There were two cases of virolactia, and 6.3% of the infant saliva samples tested positive for ZIKV. Additionally, 18.3% of the infants were in a cephalic perimeter percentile lower than 10 and had an association between microcephaly and serology or a PCR between 8.6 and 60.9%. The infant blood samples had neutralizing antibodies, indicating intrauterine protection. Microcephaly was correlated with serology or PCR, but in our study population, non-ZIKV factors may be involved as well. Low ZIKV infection values in breast milk mean that breastfeeding is safe in most of the mothers and infants of the endemic area studied.

Clinical and molecular characterization of children and adults with respiratory bocavirus infection in Mexico: a cross-sectional nested study within the ILI002 prospective observational study.

Background: Human Bocaviruses (HBoV) can cause acute respiratory tract infections. High coinfection rates cloud its pathogenicity. This study sought to describe the clinical features of HBoV1 disease in children and adults with Influenza-like illness (ILI), exploring associations between viral load, clinical features, and seasonality. Methods: Patients who tested positive for HBoV1 by polymerase chain reaction, enrolled from April 2010 to March 2014 in the ILI002 prospective observational cohort study were included in this cross-sectional nested study. Participants were included in ILI002 if they presented with signs and/or symptoms suggestive of influenza-like illness. Samples were tested for viral load, and NP1 and VP1/VP2 phylogenetic analyses, except for the samples lacking suitable and viable clinical material for genotyping. Findings: We identified HBoV1 in 157 (2.8%) of participants. Prevalence was 4.5% in children and 1.8% in adults. Single HBoV1 detection occurred in 41.1% and 46.3% of children and adults, respectively. Children commonly experienced fever (83.3%), cough with sputum (74.4%), and shortness of breath (72.2%). In the multivariate analysis of children, significant positive associations were detected between viral loads and age (0.20 [95% CI: 0.07, 0.33]), and the presence of fever (2.64 [95% CI: 1.35, 3.94]), nasal congestion (1.03 [95% CI: 0.07, 1.99]), dry cough (1.32 [95% CI: 0.42, 2.22]), chest congestion (1.57 [95% CI: 0.33, 2.80]), red eyes (1.25 [95% CI: 0.35, 2.14]), cough with sputum (1.79 [95% CI: 0.80, 2.78]), and other signs and symptoms such as chills, dizziness, and diaphoresis (1.73 [95% CI: 0.19, 3.27]). In contrast, significant negative associations were found between viral loads and percent neutrophils on the blood count (-0.04 [95% CI: -0.06, -0.02]), fatigue (-1.60 [95% CI: -2.46, -0.74]) and the presence of other symptoms or signs, including adenopathy and rash (-1.26 [95% CI: -2.31, -0.21]). Adults commonly experienced sore throat (73.1%), fatigue (77.4%), and headache (73.1%). In the multivariate analysis of adults, significant positive associations were detected between viral load and body mass index (0.13 [95% CI: 0.04, 0.21]), and the presence of confusion (1.54 [95% CI: 0.55, 2.53]), and sore throat (1.03 [95% CI: 0.20, 1.85]), and significant negative associations were detected between viral load and chest congestion (-1.16 [95% CI: -2.07, -0.24]). HBoV1 was detected throughout the year irrespective of season, temperature, and humidity. Interpretation: This study demonstrated the importance of detecting HBoV1 in patients with influenza-like illness either as single infection or co-infection, in both adults and children, and improves the characterization of HBoV1 seasonality, clinical features, and viral load. Phylogenetic analyses show a high conservation. Funding: The Mexican Emerging Infectious Diseases Clinical Research Network (LaRed), CONACYT (Fondo Sectorial SSA/IMSS/ISSSTE, Projects No. 71260 and No. 127088), Fondos federales no. HIM/2015/006, NIAID, NIH through a contract with Westat, Inc. (HHSN2722009000031, HHSN27200002), NCI, NIH (75N91019D00024, 75N91019F00130). Additional information at the end of the manuscript.

Epstein­Barr virus as a promoter of tumorigenesis in the tumor microenvironment of breast cancer (Review).

Epstein­Barr virus (EBV) is an oncovirus associated with various neoplasms, including breast cancer (BC). EBV­associated oncogenesis requires the action of several viral molecules, such as EBV nuclear antigen 3C, latent membrane protein 1, microRNAs and long non­coding RNAs, which are able of manipulating the cellular machinery, inducing an evasion of the immune system, blocking apoptosis processes, promoting cell survival and metastasis. The risk of developing cancer is associated with epigenetic alterations and alterations in various signaling pathways. The activation of all these molecules can modify the expression of EBV proteins with oncogenic activity, influencing the oncogenic process. It is clear that BC, being multifactorial, presents a greater complexity; in numerous cases, the infection associated with EBV may be crucial for this neoplasia, if particular conditions for both the virus and host are present. In the present review, all these variables are analyzed in an aim to improve the understanding of the participation of EBV in BC.

Recombinant Escherichia coli BL21 with LngA Variants from ETEC E9034A Promotes Adherence to HT-29 Cells.

The CS21 pilus produced by enterotoxigenic Escherichia coli (ETEC) is involved in adherence to HT-29 intestinal cells. The CS21 pilus assembles proteins encoded by 14 genes clustered into the lng operon. AIM: This study aimed to determine whether E. coli BL21 (ECBL) transformed with the lng operon lacking the lngA gene (pE9034AΔlngA) and complemented in trans with lngA variants of ETEC clinical strains, as well as point substitutions, exhibited modified adherence to HT-29 cells. METHODS: A kanamycin cassette was used to replace the lngA gene in the lng operon of the E9034A strain, and the construct was transformed into the ECBL strain. The pJET1.2 vector carrying lngA genes with allelic variants was transformed into ECBLpE9034AΔlngA (ECBLΔlngA). The point substitutions were performed in the pJETlngAFMU073332 vector. RESULTS: Bioinformatic alignment analysis of the LngA proteins showed hypervariable regions and clustered the clinical ETEC strains into three groups. Variations in amino acid residues affect the adherence percentages of recombinant ECBL strains with lngA variants and site-specific mutations with HT-29 cells. CONCLUSION: In this study, ECBL carrying the lng operon harboring lngA variants of six clinical ETEC strains, as well as point substitutions, exerted an effect on the adherence of ECBL to HT-29 cells, thereby confirming the importance of the CS21 pilus in adherence.

Comparative genomic analysis of uropathogenic Escherichia coli strains from women with recurrent urinary tract infection.

Introduction: Recurrent urinary tract infections (RUTIs) caused by uropathogenic Escherichia coli are costly public health problems impacting patients' quality of life. Aim: In this work, a comparative genomics analysis of three clinical RUTI strains isolated from bladder biopsy specimens was performed. Materials and methods: One hundred seventy-two whole genomes of urinary tract E. coli strains were selected from the NCBI database. The search for virulence factors, fitness genes, regions of interest, and genetic elements associated with resistance was manually carried out. The phenotypic characterization of antibiotic resistance, haemolysis, motility, and biofilm formation was performed. Moreover, adherence and invasion assays with human bladder HTB-5 cells, and transmission electron microscopy (TEM) were performed. Results: The UTI-1_774U and UTI-3_455U/ST1193 strains were associated with the extraintestinal pathotypes, and the UTI-2_245U/ST295 strain was associated with the intestinal pathotype, according to a phylogenetic analysis of 172 E. coli urinary strains. The three RUTI strains were of clinical, epidemiological, and zoonotic relevance. Several resistance genes were found within the plasmids of these strains, and a multidrug resistance phenotype was revealed. Other virulence genes associated with CFT073 were not identified in the three RUTI strains (genes for type 1 and P fimbriae, haemolysin hlyA, and sat toxin). Quantitative adherence analysis showed that UTI-1_774U was significantly (p < 0.0001) more adherent to human bladder HTB-5 cells. Quantitative invasion analysis showed that UTI-2_245U was significantly more invasive than the control strains. No haemolysis or biofilm activity was detected in the three RUTI strains. The TEM micrographs showed the presence of short and thin fimbriae only in the UTI-2_245U strain. Conclusion: The high variability and genetic diversity of the RUTI strains indicate that are a mosaic of virulence, resistance, and fitness genes that could promote recurrence in susceptible patients.

Pheromone Activity after Stimulation with Ampicillin in a Plasmid-Free Enterococcus faecalis Strain.

Enterococci exhibit clumping under the selective pressure of antibiotics. The aim of this study was to analyze the effect of supernatants from a plasmid-free clone (C29) of Enterococcus faecalis subjected to 0.25×, 0.5×, and 0.75× of the minimal inhibitory concentration (MIC) of ampicillin on the expression of an aggregation substance (AS) by a donor plasmid clone (1390R). A clumping assay was performed. The relative expression of prgB (gene that encodes AS) was determined and semiquantified in 1390R, and iad1 expression was determined and semiquantified in C29. AS expression was analyzed in the stimulated 1390R cells by confocal microscopy, flow cytometry, and ELISA. Adherence was also measured. Maximal clumping was observed with the pheromone medium 0.25×. Only the 1390R strain stimulated with the C29 supernatant without ampicillin and with 0.25× was able to express prgB. No expression of prgB was observed at 0.5× and 0.75×. The difference in relative expression (RE) of 1390R without ampicillin and with 0.25× was 0.5-fold. AS expression in 1390R showed the greatest increase upon stimulation with 0.25×. When 1390R was stimulated with 0.5× and 0.75×, AS expression was also observed but was significantly lower. Ampicillin stimulated C29 switch-off pheromone expression in recipient cells, which in turn switched off AS expression in donor cells. We observed that although prgB was switched off after 0.5× stimulation in C29, the supernatants induced expression in certain 1390R strains. In conclusion, ampicillin was able to modulate pheromone expression in free plasmid clones which, in turn, modulated AS expression in plasmid donor cells. The fact that PrgB gene expression was switched off after the ampicillin stimulus at 0.5× MIC, whereas AS proteins were present on the surface of the bacteria, suggested that a mechanism of rescue associated with mechanism pheromone sensing may be involved.

Features of antibody responses after SARS-COV-2 infection in healthcare workers in the first wave of COVID-19 pandemic in Mexico City.

OBJECTIVE: To investigate the antibody response to SARS-CoV-2 and identify associated factors in frontline and second-line healthcare workers (HCWs) at a large hospital in Mexico City during the first wave of COVID-19 pandemic. METHODS: This was a cross-sectional study of HCWs returning to work following mandatory isolation after recovering from COVID-19. Immunoglobulin (Ig) M and IgG antibodies elicited by SARS-CoV-2 were semiquantitatively measured using densitometric analysis of band intensities in lateral flow assay (LFA) devices. The mean pixel intensity (dots-per-inch [dpi]) of each band on the LFA was considered a measure of antibody titre. RESULTS: Of the 111 HCWs involved in the study, antibody responses were detected in 73/111 (66%) participants. Severe COVID symptoms was associated with old age. No differences in IgM intensity were observed between men and women, but IgG intensity was significantly higher in men than in women. Second-line HCWs produced a higher IgG intensity than firstline HCWs. The IgG intensity was high in severe cases. CONCLUSIONS: For HCWs who may acquire SARS-CoV-2 infection, it is necessary to establish a routine program for detection of the virus to avoid risk of infection and spread of COVID-19.

In Vitro Analysis of Extracts of Plant Used in Mexican Traditional Medicine, Which Are Useful to Combat Clostridioides difficile Infection.

Recently, a worrying acceleration of the emergence of antibiotic-resistant bacteria has been reported. The increase in antibiotic-associated diseases, such as Clostridioides difficile infection (CDI), has promoted research on new treatments that could be more effective and less aggressive for CDI patients. This study evaluates eight plants with antimicrobial activity commonly used in Mexican traditional medicine to evaluate their potential against C. difficile. We provide essential information about these plants' activities and action mechanisms against C. difficile and their effect on different bacterial infection activities: motility, adherence, sporulation, and germination. The selected plants are rosemary, estafiate, rue, epazote, mint, toloache, ajenjo, and thyme. We used clinical isolates to test their activity against strains responsible for current outbreaks to provide more information about the clinical impact of these extracts. We found that thyme, ajenjo, and mint were the most effective against the isolates. We identified that the extracts affected protein synthesis. In addition, the extracts affect the strains' motility, and some, such as thyme extract, affect adherence, whereas rue extract affects sporulation. These results led to the identification of new compounds beneficial to CDI treatment.

Molecular Epidemiology of Multidrug-Resistant Uropathogenic Escherichia coli O25b Strains Associated with Complicated Urinary Tract Infection in Children.

BACKGROUND: Uropathogenic Escherichia coli (UPEC) has increased the incidence of urinary tract infection (UTI). It is the cause of more than 80% of community-acquired cystitis cases and more than 70% of uncomplicated acute pyelonephritis cases. AIM: The present study describes the molecular epidemiology of UPEC O25b clinical strains based on their resistance profiles, virulence genes, and genetic diversity. METHODS: Resistance profiles were identified using the Kirby-Bauer method, including the phenotypic production of extended-spectrum ß-lactamases (ESBLs) and metallo-ß-lactamases (MBLs). The UPEC serogroups, phylogenetic groups, virulence genes, and integrons were determined via multiplex PCR. Genetic diversity was established using pulsed-field gel electrophoresis (PFGE), and sequence type (ST) was determined via multilocus sequence typing (MLST). RESULTS: UPEC strains (n = 126) from hospitalized children with complicated UTIs (cUTIs) were identified as O25b, of which 41.27% were multidrug resistant (MDR) and 15.87% were extensively drug resistant (XDR). The O25b strains harbored the fimH (95.23%), csgA (91.26%), papGII (80.95%), chuA (95.23%), iutD (88.09%), satA (84.92%), and intl1 (47.61%) genes. Moreover, 64.28% were producers of ESBLs and had high genetic diversity. ST131 (63.63%) was associated primarily with phylogenetic group B2, and ST69 (100%) was associated primarily with phylogenetic group D. CONCLUSION: UPEC O25b/ST131 harbors a wide genetic diversity of virulence and resistance genes, which contribute to cUTIs in pediatrics.

Flagella, Type I Fimbriae and Curli of Uropathogenic Escherichia coli Promote the Release of Proinflammatory Cytokines in a Coculture System.

BACKGROUND: Urinary tract infections (UTIs) are a public health problem in Mexico, and uropathogenic Escherichia coli (UPEC) is one of the main etiological agents. Flagella, type I fimbriae, and curli promote the ability of these bacteria to successfully colonize its host. AIM: This study aimed to determine whether flagella-, type I fimbriae-, and curli-expressing UPEC induces the release of proinflammatory cytokines in an established coculture system. METHODS: The fliC, fimH, and csgA genes by UPEC strain were disrupted by allelic replacement. Flagella, type I fimbriae, and curli were visualized by transmission electron microscopy (TEM). HTB-5 (upper chamber) and HMC-1 (lower chamber) cells cocultured in Transwell® plates were infected with these UPEC strains and purified proteins. There was adherence to HTB-5 cells treated with different UPEC strains and they were quantified as colony-forming units (CFU)/mL. RESULTS: High concentrations of IL-6 and IL-8 were induced by the FimH and FliC proteins; however, these cytokines were detected in low concentrations in presence of CsgA. Compared with UPEC CFT073, CFT073ΔfimH, CFT073ΔfimHΔfliC, and CFT073ΔcsgAΔfimH strains significantly reduced the adherence to HTB-5 cells. CONCLUSION: The FimH and FliC proteins are involved in IL-6 and IL-8 release in a coculture model of HTB-5 and HMC-1 cells.

Control of Methicillin-Resistant Staphylococcus aureus Strains Associated With a Hospital Outbreak Involving Contamination From Anesthesia Equipment Using UV-C.

Methicillin-resistant Staphylococcus aureus (MRSA) is considered an opportunistic pathogen in humans and is mainly associated with healthcare-associated infections (HCAIs). This bacterium colonizes the skin and mucous membranes of healthy people and causes frequent hospital outbreaks. The aim of this study was to perform molecular typing of the staphylococcal cassette chromosome mec (SCCmec) and agr loci as wells as to establish the pulsotypes and clonal complexes (CCs) for MRSA and methicillin-sensitive S. aureus (MSSA) outbreaks associated with the operating room (OR) at a pediatric hospital. Twenty-five clinical strains of S. aureus (19 MRSA and 6 MSSA strains) were recovered from the outbreak (patients, anesthesia equipment, and nasopharyngeal exudates from external service anesthesia technicians). These clinical S. aureus strains were mainly resistant to benzylpenicillin (100%) and erythromycin (84%) and were susceptible to vancomycin and nitrofurantoin. The SCCmec type II was amplified in 84% of the S. aureus strains, and the most frequent type of the agr locus was agrII, which was amplified in 72% of the strains; however, the agrI and agrIII genes were mainly detected in MSSA strains. A pulsed-field gel electrophoresis (PFGE) analysis grouped the 25 strains into 16 pulsotypes (P), the most frequent of which was P1, including 10 MRSA strains related to the anesthesia equipment, external service anesthesia technicians, and hospitalized patients. Multilocus sequence typing (MLST) identified 15 sequence types (STs) distributed in nine CCs. The most prevalent ST was ST1011, belonging to CC5, which was associated with the SCCmec type II and agrII type. We postulate that the external service anesthesia technicians were MRSA carriers and that these strains were indirectly transmitted from the contaminated anesthesia equipment that was inappropriately disinfected. Finally, the MRSA outbreak was controlled when the anesthesia equipment disinfection was improved and hand hygiene was reinforced.

Molecular Epidemiology of Acinetobacter calcoaceticus-Acinetobacter baumannii Complex Isolated From Children at the Hospital Infantil de México Federico Gómez.

The Acinetobacter calcoaceticus-baumannii (Acb) complex is regarded as a group of phenotypically indistinguishable opportunistic pathogens responsible for mainly causing hospital-acquired pneumonia and bacteremia. The aim of this study was to determine the frequency of isolation of the species that constitute the Acb complex, as well as their susceptibility to antibiotics, and their distribution at the Hospital Infantil de Mexico Federico Gomez (HIMFG). A total of 88 strains previously identified by Vitek 2®, 40 as Acinetobacter baumannii and 48 as Acb complex were isolated from 52 children from 07, January 2015 to 28, September 2017. A. baumannii accounted for 89.77% (79/88) of the strains; Acinetobacter pittii, 6.82% (6/88); and Acinetobacter nosocomialis, 3.40% (3/88). Most strains were recovered mainly from patients in the intensive care unit (ICU) and emergency wards. Blood cultures (BC) provided 44.32% (39/88) of strains. The 13.63% (12/88) of strains were associated with primary bacteremia, 3.4% (3/88) with secondary bacteremia, and 2.3% (2/88) with pneumonia. In addition, 44.32% (39/88) were multidrug-resistant (MDR) strains and, 11.36% (10/88) were extensively drug-resistant (XDR). All strains amplified the bla OXA-51 gene; 51.13% (45/88), the bla OXA-23 gene; 4.54% (4/88), the bla OXA-24 gene; and 2.27% (2/88), the bla OXA-58 gene. Plasmid profiles showed that the strains had 1-6 plasmids. The strains were distributed in 52 pulsotypes, and 24 showed identical restriction patterns, with a correlation coefficient of 1.0. Notably, some strains with the same pulsotype were isolated from different patients, wards, or years, suggesting the persistence of more than one clone. Twenty-seven sequence types (STs) were determined for the strains based on a Pasteur multilocus sequence typing (MLST) scheme using massive sequencing; the most prevalent was ST 156 (27.27%, 24/88). The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)-Cas I-Fb system provided amplification in A. baumannii and A. pittii strains (22.73%, 20/88). This study identified an increased number of MDR strains and the relationship among strains through molecular typing. The data suggest that more than one strain could be causing an infection in some patient. The implementation of molecular epidemiology allowed the characterization of a set of strains and identification of different attributes associated with its distribution in a specific environment.

Variable Expression of Notch1 and Pax5 in Classical Hodgkin Lymphoma and Infection with Epstein-Barr in Pediatric Patients.

NOTCH1 and PAX5 participate in the proliferation and differentiation of B and T lymphocytes. Their expression can be modified by activation of NOTCH1, induced by the Epstein-Barr (EBV) viral proteins identified as LMP1 and LMP2. To identify whether PAX5, NOTCH1, and EBV latency genes participate in the oncogenic process of pediatric patients with classical Hodgkin lymphoma (cHL), the present study aimed to identify the variable expression of NOTCH1 among disease subtypes and to assess its effect on PAX5 expression. A total of 41 paraffin-embedded tissues from Mexican pediatric patients with cHL were analyzed. The expression of CD30, CD20, NOTCH1, PAX5, and LMP1 was evaluated by immunohistochemistry and immunofluorescence. EBV detection was performed by in situ hybridization. Out of all cases, 78% (32/41) of the cHL cases were EBV positive. NOTCH1 expression was detected in 78.1% (25/32) of EBV-positive cases, nodular sclerosis being the most frequent subtype (11/25, 44%). In cases where the expression of both genes was identified, double immunofluorescence assays were conducted, finding no colocalization. We found that Reed-Sternberg cells had aberrant expression compared to their cells of origin (B lymphocytes) due to the molecular mechanisms involved in the loss of expression of PAX5 and that the identification of NOTCH1 could be considered as a candidate diagnostic/prognostic marker and a therapeutic target in pediatric cHL.

Molecular Epidemiology, Antibiotic Resistance, and Virulence Traits of Stenotrophomonas maltophilia Strains Associated With an Outbreak in a Mexican Tertiary Care Hospital.

Stenotrophomonas maltophilia, an emerging opportunistic pathogen, is widely distributed in the environment the resistance mechanisms, and virulence factors of this bacterium facilitate its dissemination in hospitals. This study aimed to characterize the molecular epidemiology of S. maltophilia strains associated with an outbreak in the Children's Hospital of México Federico Gómez (HIMFG). Twenty-one clinical S. maltophilia strains were recovered from cultures of blood and urine samples from 10 pediatric patients at the emergency department, and nine environmental S. maltophilia strains recovered from faucets in the same area were also included. Two of the 10 patients were related with health care-associated infections (HCAIs), and the other eight patients (8/10) were infected with environmental S. maltophilia strains. The outbreak was controlled by monthly disinfection of the faucets in the emergency department. Typing using pulsed-field gel electrophoresis (PFGE) showed a 52% genetic diversity with seven pulsotypes denoted P1-P7 among all S. maltophilia strains. Three pulsotypes (P2, P3, and P7) were identified among both the clinical and environmental S. maltophilia strains and associated with two type sequences (STs), namely, ST304 and ST24. Moreover, 80% (24/30) of the strains exhibited resistance mainly to tetracycline, 76.66% (23/30) to trimethoprim-sulfamethoxazole, and 23.33% (7/30) to the extended-spectrum ß-lactamase (ESBL) phenotype. The main resistance genes identified by multiplex PCR were sul1 in 100% (30/30), qnr in 86.66% (26/30), and intl1 in 80% (24/30) of the samples, respectively. Furthermore, the pilU, hlylII, and rmlA genes were identified in 96.6% (29/30), 90% (27/30), and 83.33% (25/30) of the samples, respectively. Additionally, 76.66% (23/30) of the S. maltophilia strains exhibited high swimming motility, 46.66% (14/30) showed moderate biofilm formation capacity, 43.33% (13/30) displayed moderate twitching motility, and 20% (6/30) exhibited high adherence. The clinical S. maltophilia strains isolated from blood most strongly adhered to HTB-9 cells. In conclusion, the molecular epidemiology and some of the features such as resistance, and virulence genes associated with colonization patterns are pathogenic attributes that can promote S. maltophilia dissemination, persistence, and facilitate the outbreak that occurred in the HIMFG. This study supports the need for faucet disinfection as a control strategy for clinical outbreaks.

Curli of Uropathogenic Escherichia coli Enhance Urinary Tract Colonization as a Fitness Factor.

Curli, a type of fimbriae widely distributed in uropathogenic Escherichia coli (UPEC), are involved in adhesion to human bladder cell surfaces and biofilm development. The role of UPEC curli was evaluated in a murine model of urinary tract infection. The aim of this study was to establish the role of curli in C57BL/6 mice transurethrally infected with curli-producing and non-curli-producing UPEC strains. We confirmed that curli enhanced UPEC colonization in the urinary tract, resulting in damage to both the bladder and kidney. Intranasal immunization with recombinant CsgA protein protected against colonization by curli-producing UPEC in the urinary tract. Quantification of cytokines from urinary tract organs showed increases in interleukin-6 and tumor necrosis factor (TNF) release in the kidneys 48 h postinfection with curli-producing UPEC. By contrast, mice infected with non-curli-producing UPEC showed the highest release of interleukin-6, -10, and -17A and TNF. Curli may obscure other fimbriae and LPS, preventing interactions with Toll-like receptors. When intranasal immunization with recombinant FimH and PapG proteins and subsequent infection with this strain were performed, cytokine quantification showed a decrease in the stimulation and release by the uroepithelium. Thus, curli are amyloid-like fimbriae that enhances colonization in the urinary tract and a possible fitness factor.

Uropathogenic Escherichia coli strains harboring tosA gene were associated to high virulence genes and a multidrug-resistant profile.

TosA, a putative repeats-in-toxin protein that has recently gained importance as an antigenic molecule, has characteristics of nonfimbrial adhesins and can act as a virulence marker in uropathogenic Escherichia coli (UPEC) strains; however, little is known about the association of this protein with antibiotic resistance profiles in UPEC tosA+ clinical strains. The aim of this study was to evaluate UPEC tosA+ strains, including examining genetic diversity, associations with phylogenetic groups, resistance profiles, virulence genes, adherence assays, integrons, and extended-spectrum beta-lactamase phenotypes. Pulsed-field gel electrophoresis analysis grouped these strains into eight clusters with 62% genetic diversity. These strains were mainly associated with the multidrug-resistant profiles, together with an association with class 1 integron and the extended-spectrum beta-lactamase phenotype. Additionally, the strains exhibited a distribution of ≥96% for core-associated genes, while a variable distribution was identified for pathogenic islands-associated genes. Strong associations between UPEC tosA+ strains and two phylogenetic groups (B2 and D) were identified, including resistance to ß-lactam and non-ß-lactam antibiotics. The UPEC tosA+ clinical strains exhibited major adherence, which was related to the fitness and virulence genes. A recombinant TosA protein reacted with antibodies from the sera of urinary tract infection patients, and anti-recombinant TosA polyclonal antibodies also detected TosA expression in these strains. In conclusion, strains of UPEC tosA+ belonging to phylogenetic group B2 had a high frequency of fitness and virulence genes associated with class 1 integrons and the extended-spectrum beta-lactamase phenotype, which exhibited a high adherence profile. The TosA protein is expressed during infection with UPEC and is considered an immunogenic molecule.

Whole-Genome Sequences of Five Acinetobacter baumannii Strains From a Child With Leukemia M2.

Acinetobacter baumannii is an opportunistic pathogen and is one of the primary etiological agents of healthcare-associated infections (HAIs). A. baumannii infections are difficult to treat due to the intrinsic and acquired antibiotic resistance of strains of this bacterium, which frequently limits therapeutic options. In this study, five A. baumannii strains (810CP, 433H, 434H, 483H, and A-2), all of which were isolated from a child with leukemia M2, were characterized through antibiotic susceptibility profiling, the detection of genes encoding carbapenem hydrolyzing oxacillinases, pulsed-field gel electrophoresis (PFGE), multilocus sequence typing (MLST), adherence and invasion assays toward the A549 cell line, and the whole-genome sequence (WGS). The five strains showed Multidrug resistant (MDR) profiles and amplification of the bla OXA-23 gene, belonging to ST758 and grouped into two PFGE clusters. WGS of 810CP revealed the presence of a circular chromosome and two small plasmids, pAba810CPa and pAba810CPb. Both plasmids carried genes encoding the Sp1TA system, although resistance genes were not identified. A gene-by-gene comparison analysis was performed among the A. baumannii strains isolated in this study and others A. baumannii ST758 strains (HIMFG and INCan), showing that 86% of genes were present in all analyzed strains. Interestingly, the 433H, 434H, and 483H strains varied by 8-10 single-nucleotide variants (SNVs), while the A2 and 810CP strains varied by 46 SNVs. Subsequently, an analysis using BacWGSTdb showed that all of our strains had the same resistance genes and were ST758. However, some variations were observed in relation to virulence genes, mainly in the 810CP strain. The genes involved in the synthesis of hepta-acylated lipooligosaccharides, the pgaABCD locus encoding poly-ß-1-6-N-acetylglucosamine, the ompA gene, Csu pili, bap, the two-component system bfms/bfmR, a member of the phospholipase D family, and two iron-uptake systems were identified in our A. baumannii strains genome. The five A. baumannii strains isolated from the child were genetically different and showed important characteristics that promote survival in a hospital environment. The elucidation of their genomic sequences provides important information for understanding their epidemiology, antibiotic resistance, and putative virulence factors.

Role of Epstein-Barr Virus in Glioblastoma.

Gliomas are the most common and most lethal primary malignant adult brain tumors, and glioblastomas are the most frequent. Several risk factors are involved in their pathogenesis; these include environmental factors as well as host factors. The etiology of most gliomas remains unknown. Epstein-Barr Virus (EBV), a member of the Herpesviridae family, was the first tumoral virus to be described, and several viruses in connection with cancer were discovered thereafter. During the complex interaction between host and EBV, several events take place. In the context of survival, EBV can drive its host cells with subsequent disruption of the cellular machinery, leading to tumorigenesis as the final outcome. Thus, the EBV infection has been associated with different tumors. In this review, we discuss EBV and cancer. We have analyzed previously published papers and have conducted a critical analysis on the role of the viral infection in glioblastoma. Several works have described the presence of the virus, but none have shown a conclusive association. Thus, there is need to continue analyzing the interaction between host and virus to determine whether the viral presence is incidental or has some association with glioblastoma.

Correction: Features of urinary Escherichia coli isolated from children with complicated and uncomplicated urinary tract infections in Mexico.

[This corrects the article DOI: 10.1371/journal.pone.0204934.].