A novel chaperone-effector-immunity system identified in uropathogenic Escherichia coli UMN026.

Background: Urinary tract infections (UTIs) are very common worldwide. According to their symptomatology, these infections are classified as pyelonephritis, cystitis, or asymptomatic bacteriuria (AB). Approximately 75-95% of UTIs are caused by uropathogenic Escherichia coli (UPEC), which is an extraintestinal bacterium that possesses virulence factors for bacterial adherence and invasion in the urinary tract. In addition, UPEC possesses type 6 secretion systems (T6SS) as virulence mechanisms that can participate in bacterial competition and in bacterial pathogenicity. UPEC UMN026 carries three genes, namely, ECUMN_0231, ECUMN_0232, and ECUMN_0233, which encode three uncharacterized proteins related to the T6SS that are conserved in strains from phylogroups B2 and D and have been proposed as biomarkers of UTIs. Aim: To analyze the frequency of the ECUMN_0231, ECUMN_0232, ECUMN_0233, and vgrG genes in UTI isolates, as well as their expression in Luria Bertani (LB) medium and urine; to determine whether these genes are related to UTI symptoms or bacterial competence and to identify functional domains on the putative proteins. Methods: The frequency of the ECUMN and vgrG genes in 99 clinical isolates from UPEC was determined by endpoint PCR. The relationship between gene presence and UTI symptomatology was determined using the chi2 test, with p < 0.05 considered to indicate statistical significance. The expression of the three ECUMN genes and vgrG was analyzed by RT-PCR. The antibacterial activity of strain UMN026 was determined by bacterial competence assays. The identification of functional domains and the docking were performed using bioinformatic tools. Results: The ECUMN genes are conserved in 33.3% of clinical isolates from patients with symptomatic and asymptomatic UTIs and have no relationship with UTI symptomatology. Of the ECUMN+ isolates, only five (15.15%, 5/33) had the three ECUMN and vgrG genes. These genes were expressed in LB broth and urine in UPEC UMN026 but not in all the clinical isolates. Strain UMN026 had antibacterial activity against UPEC clinical isolate 4014 (ECUMN-) and E. faecalis but not against isolate 4012 (ECUMN+). Bioinformatics analysis suggested that the ECUMN genes encode a chaperone/effector/immunity system. Conclusions: The ECUMN genes are conserved in clinical isolates from symptomatic and asymptomatic patients and are not related to UTI symptoms. However, these genes encode a putative chaperone/effector/immunity system that seems to be involved in the antibacterial activity of strain UMN026.

Association of PADI2 and PADI4 polymorphisms in COVID-19 host severity and non-survival.

Background: Enzymes of the peptidylarginine deiminase family (PADs) play a relevant role in the pathogenesis of COVID-19. However, the association of single nucleotide polymorphisms (SNPs) in their genes with COVID-19 severity and death is unknown. Methodology: We included 1045 patients who were diagnosed with COVID-19 between October 2020 and December 2021. All subjects were genotyped for PADI2 (rs1005753 and rs2235926) and PADI4 (rs11203366, rs11203367, and rs874881) SNPs by TaqMan assays and their associations with disease severity, death, and inflammatory biomarkers were evaluated. Results: 291 patients presented had severe COVID-19 according to PaO2/FiO2, and 393 had a non-survival outcome. Carriers of the rs1005753 G/G genotype in the PADI2 gene presented susceptibility for severe COVID-19, while the heterozygous carriers in rs11203366, rs11203367, and rs874881 of the PADI4 gene showed risk of death. The GTACC haplotype in PADI2-PADI4 was associated with susceptibility to severe COVID-19, while the GCACC haplotype was a protective factor. The GCGTG haplotype was associated with severe COVID-19 but as a protective haplotype for death. Finally, the GTACC haplotype was associated with platelet-to-lymphocyte ratio (PLR), the GCACC haplotype with neutrophil-to-hemoglobin and lymphocyte and the GCGTG haplotype as a protective factor for the elevation of procalcitonin, D-dimer, CRP, LCRP, NHL, SII, NLR, and PLR. Conclusions: Our results suggest that the haplotypic combination of GTACC and some individual genotypes of PADI2 and PADI4 contribute to the subjects' susceptibility for severity and death by COVID-19.

Changes in lifestyle and physical and mental health related to long-confinement due COVID-19: a study during the first and second pandemic waves in Mexico and Chile.

We investigate changes in lifestyle, physical, and mental health during the confinement period of the first and second waves of COVID-19, as well as their relation to sociodemographic parameters and confinement status. Sociodemographic data and information regarding changes in their lifestyle behavior and changes in body weight and physical activity (PA) were collected. The SF-36 questionnaire was implemented for measuring the domains related to physical health (PH) and mental health (MH). The growth frequency of weight gain in the Mexican (4.8%) and Chilean (10.9%) populations was observed during the second wave. The MH component decreased in the Mexican and the Chilean population (p < 0.05). Moreover, the MH decreased significantly according to the degree of confinement (p < 0.01). Although some sociodemographic factors were related to the presence of a very low score (<50 scores) for the MH component during the first wave, it is perceived as a higher relative risk during the second wave in both populations. The long confinement due to COVID-19 is associated to negative changes in nutritional and physical lifestyle behavior, affecting mainly the MH component.

Enterotoxigenic profiles and submerged and interface biofilms in Bacillus cereus group isolates from foods / Perfiles enterotoxigénicos y biopelículas de superficie y sumergidas en aislados del grupo Bacillus cereus de alimentos

Abstract Biofilm formation by Bacillus cereus strains is now recognized as a systematic contaminaron mechanism in foods; the aim of this study was to evaluate the production of submerged and interface biofilms in strains of B. cereus group in different materials, the effect of dex-trose, motility, the presence of genes related to biofilms and the enterotoxigenic profile of the strains. We determine biofilm production by safranin assay, motility on semi-solid medium, toxin gene profiling and genes related to biofilm production by PCR in B. cereus group iso-lated from food. In this study, we observe strains used a higher production of biofilms in PVC; in the BHI broth, no submerged biofilms were found compared to phenol red broth and phenol red broth supplemented with dextrose; no strains with the ces gene were found, the enterotoxin profile was the most common the profile that includes genes for the three enterotoxins. We observed a different distribution of tasA and sipW with the origin of isolation of the strain, being more frequent in the strains isolated from eggshell. The production and type of biofilms are differential according to the type of material and culture medium used.

Resumen La formación de biopelículas por cepas de Bacillus cereus es reconocida como un mecanismo de contaminación sistemática en alimentos; el objetivo del estudio fue evaluar la producción de biopelículas sumergidas y de superficie en cepas del grupo de Bacillus cereus en diferentes materiales, el efecto de la dextrosa, la motilidad, la presencia de genes relacionados a biopelículas y el perfil enterotoxigénico de las cepas. Determinamos la producción de biopelículas por el ensayo de safranina, motilidad en medio sólido, perfil enterotoxigénico y genes relacionados a producción de biopelículas por PCR en aislados del grupo de Bacillus cereus de alimentos. En este estudio, observamos en las cepas utilizadas una alta producción de biopelículas en PVC; en caldo BHI, no se encontraron biopelículas sumergidas en comparación con el caldo rojo de fenol y caldo rojo de fenol suplementando con dextrosa; no se encontraron cepas con el gen ces, el perfil de enterotoxinas más común fue el perfil que incluía los genes de las tres enterotoxinas, también observamos una distribución diferente de tasA y sipW con relación al origen de la cepa, siendo más frecuente estos genes en las cepas aisladas de huevos. La producción y el tipo de biopelículas es diferente de acuerdo con el tipo de material y el medio de cultivo utilizado.

Bacillus cereus in the Artisanal Cheese Production Chain in Southwestern Mexico.

BACKGROUND: Bacillus cereus is associated with milk, dairy product, and dairy farm contamination. The aim of this study was to characterize strains of B. cereus in the small-scale artisanal cheese production chain in southwestern Mexico. METHODS: 130 samples were collected. B. cereus isolation was performed on Mannitol Egg Yolk Polymyxin (MYP) agar. Genotyping, enterotoxigenic profile, and determination of genes involved in the formation of B. cereus biofilm were performed by PCR. An antimicrobial susceptibility test was made by broth microdilution assay. The phylogenetic analysis was performed by amplification and sequencing of 16s rRNA. RESULTS: B. cereus sensu lato was isolated and molecularly identified in 16 samples and B. cereus sensu stricto (B. cereus) was the most frequently isolated and identified species (81.25%). Of all the isolated B. cereus sensu lato strains, 93.75% presented at least one gene for some diarrheagenic toxins, 87.5% formed biofilms, and 18.75% were amylolytic. All B. cereus sensu lato strains were resistant to beta-lactams and folate inhibitors. A close phylogenetic relationship between isolates was found between the cheese isolates and the air isolates. CONCLUSIONS: Strains of B. cereus sensu lato were found in small-scale artisanal cheeses on a farm in southwestern Mexico.

Enterotoxigenic profiles and submerged and interface biofilms in Bacillus cereus group isolates from foods.

Biofilm formation by Bacillus cereus strains is now recognized as a systematic contamination mechanism in foods; the aim of this study was to evaluate the production of submerged and interface biofilms in strains of B. cereus group in different materials, the effect of dextrose, motility, the presence of genes related to biofilms and the enterotoxigenic profile of the strains. We determine biofilm production by safranin assay, motility on semi-solid medium, toxin gene profiling and genes related to biofilm production by PCR in B. cereus group isolated from food. In this study, we observe strains used a higher production of biofilms in PVC; in the BHI broth, no submerged biofilms were found compared to phenol red broth and phenol red broth supplemented with dextrose; no strains with the ces gene were found, the enterotoxin profile was the most common the profile that includes genes for the three enterotoxins. We observed a different distribution of tasA and sipW with the origin of isolation of the strain, being more frequent in the strains isolated from eggshell. The production and type of biofilms are differential according to the type of material and culture medium used.

Potential Impact of Prosthetic Biomaterials on the Periodontium: A Comprehensive Review.

The success of a prosthetic treatment is closely related to the periodontal health of the individual. The aim of this article was to review and present the importance of prosthetic restorative materials on the condition of the periodontium, the changes that occur in the composition of the subgingival microbiota and the levels of inflammatory markers in gingival crevicular fluid. Articles on the influence of different prosthetic restorative materials on subgingival microbiota and proinflammatory cytokines were searched for using the keywords "prosthetic biomaterials", "fixed prosthesis", "periodontal health", "subgingival microbiota", "periodontal biomarkers" and "gingival crevicular fluid" in PubMed/Medline, Science Direct, Scopus and Google Scholar. The type of material used for prosthesis fabrication together with poor marginal and internal fit can result in changes in the composition of the subgingival microbiota, as well as increased accumulation and retention of dentobacterial plaque, thus favoring the development of periodontal disease and prosthetic treatment failure. Biological markers have helped to understand the inflammatory response of different prosthetic materials on periodontal tissues with the main purpose of improving their clinical application in patients who need them. Metal-free ceramic prostheses induce a lower inflammatory response regardless of the fabrication method; however, the use of CAD/CAM systems is recommended for their fabrication. In addition, it is presumed that metal-ceramic prostheses cause changes in the composition of the subgingival microbiota producing a more dysbiotic biofilm with a higher prevalence of periodontopathogenic bacteria, which may further favor periodontal deterioration.

Serum Levels of IFABP2 and Differences in Lactobacillus and Porphyromonas gingivalis Abundance on Gut Microbiota Are Associated with Poor Therapeutic Response in Rheumatoid Arthritis: A Pilot Study.

Intestinal dysbiosis is related to the physiopathology and clinical manifestation of rheumatoid arthritis (RA) and the response to pharmacologic treatment. The objectives of this study were (1) to analyze the effect of conventional synthetic disease modifying anti-rheumatic drugs (csDMARDs) on the abundance of gut microbiota's bacteria; (2) to evaluate the relationship between the differences in microbial abundance with the serum levels of intestinal fatty-acid binding protein 2 (IFABP2), cytokines, and the response phenotype to csDMARDs therapy in RA. A cross-sectional study was conducted on 23 women diagnosed with RA. The abundance of bacteria in gut microbiota was determined with qPCR. The ELISA technique determined serum levels of IFABP2, TNF-α, IL-10, and IL-17A. We found that the accumulated dose of methotrexate or prednisone is negatively associated with the abundance of Lactobacillus but positively associated with the abundance of Bacteroides fragilis. The Lactobacillus/Porphyromonas gingivalis ratio was associated with the Disease Activity Score-28 for RA with Erythrocyte Sedimentation Rate (DAS28-ESR) (r = 0.778, p = 0.030) and with the levels of IL-17A (r = 0.785, p = 0.027) in the group treated with csDMARD. Moreover, a relation between the serum levels of IFABP2 and TNF-α (r = 0.593, p = 0.035) was observed in the group treated with csDMARD. The serum levels of IFABP2 were higher in patients with secondary non-response to csDMARDs therapy. In conclusion, our results suggest that the ratios of gut microbiota's bacteria and intestinal permeability seems to establish the preamble for therapeutic secondary non-response in RA.

Characterization of Staphylococcus epidermidis clinical isolates from hospitalized patients with bloodstream infection obtained in two time periods.

Background: In recent years Staphylococcus epidermidis has been considered an important and frequent causative agent of health care-associated infections (HAIs), increasing the costs of hospitalization, morbidity, and mortality. Antibiotic resistance and biofilm formation are the most important obstacles in the treatment of infections caused by this microorganism. The aim of this work was to determine the most prevalent STs, as well as the antibiotic resistance profile and biofilm formation of S. epidermidis clinical isolates obtained from hospitalized patients in two hospitals in Acapulco, Guerrero in two time periods. Methods: Twenty methicillin-resistant S. epidermidis strains isolated from patients with bacteremia in two hospitals in two time periods were analyzed. Identification and antibiotic susceptibility were performed using the Vitek automated system. Molecular confirmation of the identification and methicillin resistance was performed by duplex PCR of the mecA and nuc genes. Biofilm production was analyzed, and the clonal origin was determined by multilocus sequence typing (MLST). Results: We identified 14 antibiotic resistance profiles as well as 13 sequence types (ST), including the new ST761. We also found that ST2 and ST23 were the most prevalent and, together with ST59, were found in both time periods. Seventeen of our clinical isolates were multidrug-resistant, but all of them were sensitive to linezolid and vancomycin, and this was not related to biofilm production. Additionally, we standardized a duplex PCR to identify methicillin-resistant S. epidermidis strains. In conclusion, S. epidermidis STs 2, 23, and 59 were found in both time periods. This study is the first report of S. epidermidis ST761. The clinical isolates obtained in this work showed a high multidrug resistance that is apparently not related to biofilm production.

Genetic diversity of enterotoxigenic Bacillus cereus strains in coriander in southwestern Mexico.

Background: Coriander, like other leafy green vegetables, is available all year round and is commonly consumed raw in Mexico as in other countries in the preparation of street or homemade food. Bacillus cereus (B. cereus) is a microorganism that can reach coriander because it is usually found in the soil and in some regions the vegetables are irrigated with polluted water. Therefore, the aim of this study was to determinate the presence of B. cereus in coriander used for human consumption in southwestern Mexico and determine the toxigenic profile, biofilm production, genes associated with the production of biofilms, sporulation rates, enzymatic profile, psychotropic properties, and genetic diversity of B. cereus. Methods: Fresh coriander samples were collected from several vegetable retailers in different markets, microbiological analysis was performed. Molecular identification, genes related to the production of biofilm, and toxin gene profiling of B. cereus isolates were determined by PCR. The biofilm formation was measured by performing a crystal violet assay. The genetic diversity of B. cereus strains was determined by PCR of repetitive elements using oligonucleotide (GTG) 5. Results: We found a frequency of B. cereus in vegetables was 20% (13/65). In this study, no strains with genes for the HBL toxin were found. In the case of genes related to biofilms, the frequency was low for sipW [5.8%, (1/17)] and tasA [11.7%, (2/17)]. B. cereus strains produce a low amount of biofilm with sporulation rates around 80%. As for genetic diversity, we observed that strains isolated from the same market, but different vegetable retailers are grouped into clusters. In the coriander marketed in southwestern Mexico, were found B. cereus strains with genes associated with the production of diarrheal toxins. Together, these results show actual information about the state of art of B. cereus strains circulating in the southwestern of Mexico.

Influence of Diet and Levels of Zonulin, Lipopolysaccharide and C-Reactive Protein on Cardiometabolic Risk Factors in Young Subjects.

A western diet and increased intestinal permeability may contribute to systemic inflammation and the development of cardio-metabolic alterations. The aim of this study was to assess the relationship between diet, biomarkers of intestinal permeability, and chronic low-grade inflammation on the cardiometabolic profile. A cross-sectional study was carried out in 238 young subjects aged 18-29 years, divided into two groups: with <3 cardiometabolic risk factors (CRF) and ≥3 risk factors. Anthropometric parameters, biochemical profile, and serum levels of zonulin, lipopolysaccharide (LPS), and high-sensitivity C-reactive protein (hs-CRP) were measured, and the macronutrient intake was evaluated. Interaction models showed elevated glucose levels in the presence of high biomarker levels: zonulin ≥51.6 ng/mL plus LPS ≥ 1.35 EU/mL (ß = 1.1, p = 0.006), and LPS ≥1.35 EU/mL plus hs-CRP ≥ 4.3 mg/L (ß = 1.2, p = 0.007). In addition, triglyceride levels increased in the presence of LPS ≥ 1.35 EU/mL and hs-CRP ≥ 4.3 mg/L (ß = 3.9, p = 0.01). Despite having increased biomarker levels, a higher consumption of water (≥2100 mL), polyunsaturated fatty acids (≥6.0 g), or fiber (≥30 g) decreased triglyceride (ß = -9.6, p = 0.03), total cholesterol (ß = -5.1, p = 0.01), and LDL-C levels (ß = -7.7, p = 0.01). These findings suggest that the increased consumption of water, PUFA and fiber may improve lipid profile in subjects with intestinal permeability dysfunction or low-grade systemic inflammation.

PADI2 Polymorphisms Are Significantly Associated With Rheumatoid Arthritis, Autoantibodies Serologic Status and Joint Damage in Women from Southern Mexico.

The enzymes of the family peptidylarginine deiminases (PADs) have an important role in the pathogenesis of rheumatoid arthritis (RA) due to their association with the anti-citrullinated protein antibodies (ACPA) production. To evaluate the association between single-nucleotide polymorphisms (SNPs) in the PADI2 gene and RA susceptibility, related clinical parameters, and the serologic status of autoantibodies in a women population with RA from southern Mexico, a case-control study was conducted (case n=229; control n=333). Sociodemographic characteristics were evaluated, along with clinical parameters, inflammation markers, the levels of ACPAs as anti-cyclic citrullinated peptides (anti-CCPs), anti-modified citrullinated vimentin (anti-MCV), and rheumatoid factor (RF). Genomic DNA was extracted from peripheral blood, and three SNPs of the PADI2 gene (rs1005753, rs2057094, and rs2235926) were performed by qPCR using TaqMan probes. The data analysis reveals that the carriers of the T allele for rs2057094 and rs2235926 presented an earlier onset of the disease (ß= -3.26; p = 0.03 and ß = -4.13; p = 0.015, respectively) while the carriers of the T allele for rs1005753 presented higher levels of anti-CCPs (ß= 68.3; p = 0.015). Additionally, the T allele of rs2235926 was associated with a positive RF (OR = 2.90; p = 0.04), anti-MCV (OR = 2.92; p = 0.05), and with the serologic status anti-CCP+/anti-MCV+ (OR = 3.02; p = 0.03), and anti-CCP+/anti-MCV+/RF+ (OR = 3.79; p = 0.004). The haplotypes GTT (OR =1.52; p = 0.027) and TTT (OR = 1.32; p = 0.025) were associated with the presence of RA. In addition, in this study the haplotype TTT is linked to the presence of radiographic joint damage defined by a Sharp-van der Heijde score (SHS) ≥2 (OR = 1.97; p = 0.0021) and SHS ≥3 (OR = 1.94; p = 0.011). The haplotype TTT of SNPs rs1005753, rs2057094, and rs2235926 of the PADI2 gene confers genetic susceptibility to RA and radiographic joint damage in women from southern Mexico. The evidence reveals that SNPs of the PADI2 gene favors the presence of a positive serologic status in multiple autoantibodies and the clinical manifestations of RA at an early onset age.

Low Seroprevalence of Measles-Specific IgG in Children of Three Ethnic Groups from Mexico: Influence of Age, Sex, Malnutrition and Family Size.

BACKGROUND: The reemergence of measles represents a public health problem. The aim of the study was to determine the seroprevalence of IgG antibodies against measles in children of three ethnic groups in southern Mexico and the nutritional status and demographic risk factors associated. METHODS: A cross-sectional study in 416 school-age children, 207 belonging to the Tlapaneco ethnic group, 101 to the Mixteco group and 108 were considered Mestizo. Sociodemographic data were collected, an anthropometric evaluation of the children was performed and a fasting blood sample was obtained from each child for the measurement of measles IgG antibodies by Enzyme-Linked Immunosorbent Assay (ELISA). RESULTS: From the total sample, 59% of the children were seropositive for IgG antibodies against measles; in contrast, 41% lacked IgG antibodies. Measles antibody seropositivity was higher in girls (64%). 90.5% of 6-year-old children had higher antibodies seroprevalence, compared to the children between 10 and 13 years old (45.5%). In the three ethnic groups, age was negatively correlated with the index standard ratio (ISR) of measles antibody levels and the families with ≥8 members showed less seropositivity. According to the antibodies levels, most of the positive cases remained around 1 Standard Deviation (SD) of the ISR values and no underweight children had antibody levels above 2 SD. CONCLUSIONS: The Anti-Measles serological coverage is low in children of three ethnic groups from Southern Mexico and the age, sex, malnutrition and family size are associated factors. Therefore, it is important to strengthen immunization campaigns, principally in vulnerable groups.

Obesity, dyslipidemia, and high blood pressure are associated with cardiovascular risk, determined using high-sensitivity C-reactive protein concentration, in young adults.

OBJECTIVE: Few studies have investigated the relationships between high-sensitivity C-reactive protein (hs-CRP) concentration and conventional cardiometabolic markers in young adults. The aim of this study was to characterize the cardiometabolic profile of young adults who are at high cardiovascular risk, according to hs-CRP concentration. METHODS: A cross-sectional study was conducted in 300 young adults (18 to 30 years old) from southern Mexico (n = 150 normal-weight and n = 150 obese). Their circulating lipid and glucose concentrations were measured using colorimetric enzymatic assays, and their hs-CRP, ApoA, and ApoB concentrations were measured using turbidimetric assays. RESULTS: The most prevalent abnormalities in the participants with high cardiovascular risk, determined using an hs-CRP >28.57 nmol/L, were high waist circumference (85.7%), obesity (83.9%), high low-density lipoprotein-cholesterol (64.3%), low high-density lipoprotein-cholesterol (50%), Apo B in the highest tertile (39.3%), hypertriglyceridemia (35.7%), and high blood pressure (30.4%). In addition, there were strong associations between hs-CRP >28.57 nmol/L and obesity (odds ratio [OR] = 13.9), high waist circumference (OR = 8.0), hypertriglyceridemia (OR = 4.0), high blood pressure (OR = 3.4), hypercholesterolemia (OR = 2.8), and Apo B in the highest tertile (OR = 2.4). CONCLUSION: The principal cardiometabolic alterations associated with high cardiovascular risk, determined using hs-CRP, are obesity, dyslipidemia, and high blood pressure in young adults.

DMARDs-Gut Microbiota Feedback: Implications in the Response to Therapy.

Due to its immunomodulatory effects and the limitation in the radiological damage progression, disease-modifying antirheumatic drugs (DMARDs) work as first-line rheumatoid arthritis (RA) treatment. In recent years, numerous research projects have suggested that the metabolism of DMARDs could have a role in gut dysbiosis, which indicates that the microbiota variability could modify the employment of direct and indirect mechanisms in the response to treatment. The main objective of this review was to understand the gut microbiota bacterial variability in patients with RA, pre and post-treatment with DMARDs, and to identify the possible mechanisms through which microbiota can regulate the response to pharmacological therapy.

Genetic Diversity and Virulence Factors of S. aureus Isolated from Food, Humans, and Animals.

Staphylococcus aureus is a commensal bacterium in humans and animals able to adapt to multiple environments. The aim of this study was to compare the genetic diversity and virulence profiles of strains of S. aureus isolated from food (29 strains), humans (43 strains), and animals (8 strains). 80 lipase-producing strains belonging to a biobank of 360 isolates, identified phenotypically as S. aureus, were selected. Confirmation of the species was made by amplifying the spA gene and 80% (64/80) of the strains were confirmed within this species. The virulence profile of each of the isolates was determined by PCR. The seA gene coding for enterotoxin A was found in 53.1% of the strains, the saK gene, which codes for Staphylokinase, was amplified in 57.8% of the strains, and, finally, the hlB gene coding for ß-Hemolysin was amplified in 17.2%. The profile of antimicrobial resistance was determined by the Kirby Bauer method showing that the strains from food presented greater resistance to erythromycin (40.7%) and ciprofloxacin (18.5%) while in strains isolated from humans were to erythromycin (48.4%) and clindamycin (21.2%). Also, in strains from animals, a high resistance to erythromycin was observed (75%). The frequency of MRSA was 12.5% due to the presence of the mec gene and resistance to cefoxitin. Of the total strains, 68.7% were typed by PCR-RFLP of the coa gene using the AluI enzyme; derived from this restriction, 17 profiles were generated. Profile 4 (490 bp, 300 bp) was the most frequent, containing a higher number of strains with a higher number of virulence factors and antimicrobial resistance, which is associated with greater adaptation to different environments. In this study, a wide genetic diversity of strains of S. aureus from different foods, humans, and animals was found. This demonstrates evolution, genetic versatility, and, therefore, the adaptation of this microorganism in different environments.

Periodontal disease distribution, risk factors, and importance of primary healthcare in the clinical parameters improvement / Distribución de la enfermedad periodontal, factores de riesgo e importancia de la atención primaria en salud en la mejora de los parámetros clínicos

The objective of this study is to show the distribution of periodontal disease, risk factors, and importance of primary healthcare, for the improvement of clinical parameters. Two phases study transversal and nonrandomized trial (before - after), with educational intervention and conservative treatment, were carried out at Dental School of the Universidad Autónoma de Guerrero México, in 161 subjects who met the inclusion criteria. Oral healthcare education was carried out as well as conservative periodontal treatment, with six months follow up. Clinical measurements were performed with a Williams probe, O'Leary plaque index, calculus index and dental mobility Miller method. Periodontal disease was found on 82 % of all participants. Multinomial logistic regression analysis showed an odds ratio of 14.3 (95 % CI: 2.5, 82.1), 13.4 (95 % CI: 1.7, 103.5), 29.2 (95 % CI: 3.2, 260.9) and 68 (95 % CI: 6.6, 711.0) plaque in gingivitis, mild, moderate and severe chronic periodontitis, respectively. The longitudinal panel data analysis showed a significant effect (p <0.001) in the mean decrease of the clinical parameters after intervention, probing depth 0.4 mm (95 % CI: -0.5, -0.3), pockets depth 1.1 mm (95 % CI: -1.3, -0.9), amount of pockets 4.5 (95 % CI: -5.2, -3.7), bleeding 5.2 (95 % CI: -5.9, -4.5) and dental mobility 0.6 degrees (95 % CI: -0.7, -0.5). Primary healthcare is still the best option to improve the periodontal health in population who do not have access to specialty services. Dentists can achieve significant clinical improvement at very low cost, if they are aware of primary health care.

El objetivo del estudio fue mostrar la distribución de la enfermedad periodontal, los factores de riesgo y la importancia de la atención primaria de salud, para la mejora de los parámetros clínicos. Material y método: Estudio de dos fases transversal y no aleatorizado (antes - después), con intervención educativa y tratamiento conservador, realizado en la Facultad de Odontología de la Universidad Autónoma de Guerrero México, en 161 sujetos que cumplieron con los criterios de inclusión. Se llevó a cabo una educación sanitaria oral, así como un tratamiento periodontal conservador, con un seguimiento de seis meses. Las mediciones clínicas se realizaron con una sonda Williams, el índice de placa O'Leary, el índice de cálculo y el método Miller de movilidad dental. Resultados: se encontró enfermedad periodontal en el 82 % de todos los participantes. El análisis de regresión logística multinomial mostró un odds ratio de 14.3 (IC 95 %: 2.5, 82.1), 13.4 (IC 95 %: 1.7, 103.5), 29.2 (IC 95 %: 3.2, 260.9) y 68 (IC 95 %: 6.6, 711.0) placa en gingivitis, periodontitis crónica leve, moderada y grave, respectivamente. El análisis de datos del panel longitudinal mostró un efecto significativo (p <0.001) en la disminución media de los parámetros clínicos después de la intervención, profundidad de sondeo 0.4 mm (IC 95 %: -0.5, -0.3), profundidad de bolsillos 1.1 mm (IC 95 %: -1.3, -0.9), cantidad de bolsillos 4.5 (IC 95 %: -5.2, -3.7), hemorragia 5.2 (IC 95 %: -5.9, -4.5) y movilidad dental 0.6 grados (IC 95 %: -0.7, - 0.5). Conclusiones: la atención primaria de salud sigue siendo la mejor opción para mejorar la salud periodontal en la población que no tiene acceso a servicios especializados. Relevancia clínica: los dentistas pueden lograr una mejora clínica significativa a un costo muy bajo, si conocen la atención primaria de salud.

Prevalence of the Strains of Bacillus cereus Group in Artisanal Mexican Cheese.

Bacillus cereus is a microorganism associated with food poisoning. It has been found in products, such as milk and dairy products. The aim of this study was to isolate and identify B. cereus group strains in artisan cheeses sold in southwestern Mexico, as well as its toxigenic profile, its psychrophilic ability, and its biofilm production. B. cereus isolation was performed on Mannitol Yolk Polymyxin (MYP) agar and this was molecularly confirmed by the amplification of the gyrB gene. Polymerase chain reaction was used to determine the toxigenic profile, amplifying conserved regions of hblABD and nheABC operons, which code for the subunits of Hbl and Nhe toxins, respectively, as well as ges and cytK genes, which code for toxin cereulide and cytotoxin K (Cytk). Frequency of B. cereus contamination in artisan cheeses was 29.48% (23/78), and the bacterium was isolated in similar quantities in all types of products. All strains were amylase positive, and 60.86% (14/23) were able to produce biofilm; 91.30% (21/23) of the strains were psychrophilic. In most of the strains, at least one gene related to enterotoxins was identified (21/23). B. cereus strains in this study have a high toxigenic potential, which increases the risk of food poisoning due to the consumption of artisan cheeses made in Mexico.

Relationship between TNF-α, MMP-8, and MMP-9 levels in gingival crevicular fluid and the subgingival microbiota in periodontal disease.

Periodontitis is modulated by a complex dysbiotic microbiota, these species stimulate upward the production of pro-inflammatory cytokines such as TNF-α, which, in turn, upregulates the production of bone resorption molecules. Enzymes such as MMP-8 and 9 have been associated with the destructive disease. This study evaluated the composition of periodontal microbiota with the checkerboard hybridization technique and its correlation with TNF-α, MMP-8, and MMP-9 evaluated with ELISA, of 80 patients (45 healthy, and 35 with chronic periodontitis). The frequency of the 18 species evaluated was higher in patients with bone loss compared with control group. TNF-α in gingival crevicular fluid was significantly higher in bone loss group (p < 0.01); MMP-8 (p = 0.34) by MMP-9 (p < 0.05) in bone loss group obtained lower values than in control group. Positive correlation of TNF-α was obtained with Aggregatibacter actinomycetemcomitans (rho = 0.38; p < 0.01), Fusobacterium nucleatum (rho = 0.25; p < 0.05) and Porphyromonas gingivalis (rho = 0.26; p < 0.05); negative correlation of MMP-8 with A. actinomycetemcomitans (rho = 0.26; p < 0.01), Capnocytophaga sputigena (rho = 0.33; p < 0.01), and F. nucleatum (rho = 0.21; p < 0.05); also negative correlation of MMP-9 with F. nucleatum (rho = 0.23; p < 0.05), P. gingivalis (rho = 0.23; p < 0.05), and Tannerella forsythia (rho = 0.26; p < 0.01). TNF-α increased due to the increase in each count of A. actinomycetemcomitans (ß = 0.57; p = 0.00). The presence of A. actinomycetemcomitans (ß = 1.88; p = 0.00), Campylobacter rectus (ß = 0.78; p = 0.01), F. nucleatum (ß = 0.65; p = 0.04), and P. gingivalis (ß = 0.65; p = 0.04) significantly increases TNF-α levels. TNF-α in gingival crevicular fluid, despite the minimal amounts collected, is a good biomarker of periodontal disease; since levels of TNF-α increases with the increase of the most harmful species to the periodontium.

Prevalencia de cepas del grupo de Bacillus cereus productoras de biopelicula en helados comercializados en México / Prevalence of strains of the Bacillus cereus group biofilm producers in ice cream in Mexico

El helado es un vehículo para la transmisión de patógenos como Bacillus cereus. Por lo cual, se determinó la frecuencia de cepas del grupo Bacillus cereus en helados, perfil enterotoxigénico, psicrofilia y producción de biopelícula. Un total de 230 muestras de seis marcas de helado de producción y distribución nacional fueron colectadas en México. El análisis microbiológico incluyó aislamiento en agar manitol yema de huevo. Las cepas se identificaron molecularmente a partir de la amplificación del gen de la topoisomerasa (gyrB) y el perfil enterotoxigénico por la amplificación de regiones conservadas de los operones nheABC y hblABD y del gen cytK. Además, se determinó la producción de biopelícula en vidrio y policloruro de vinilo. La frecuencia de contaminación por cepas del grupo B. cereus fue de 3,6%, se encontró una cepa positiva para nheABC y cinco para cytK, el 87,5% de las cepas generó biopelícula en vidrio y todas en policloruro de vinilo, dos cepas fueron psicrofilicas. En conclusión, en el helado distribuido en México, se encontró una baja contaminación por cepas del grupo B. cereus con alta producción de biopelícula; sin embargo, no se debe subestimar el potencial enterotoxigénico de estas cepas

Ice cream is a medium for microbial growth due to its nutritional value and neutral pH. Therefore, the frequency of strains of the Bacillus cereus group in ice cream was determined, the enterotoxigenic profile, psychrophilic strains and biofilm production. A total of 230 samples of six brands of ice cream produced and distributed nationwide were collected in Mexico. The microbiological analysis was a cold pre-enrichment and isolation of the microorganism in egg yolk agar. The strains were identified molecularly from the amplification of the topoisomerase gene (gyrB) and the enterotoxigenic profile by the amplification of conserved regions of the nheABC and hblABD operons and of the cytK gene. In addition, the production of biofilm in glass and polyvinyl chloride and psychophilia was determined. The frequency of contamination by strains of the B. cereus group was 3.6%, a positive strain was found for nheABC and five for cytK, 87.5% of the strains generated biofilm in glass and all in polyvinyl chloride, two strains were psychrophilic. In the ice cream distributed in Mexico, a low contamination by strain of the B. cereus group was found, however, the enterotoxigenic potential of the strains should not be underestimated