PFGE dendrogram of <i>S. hominis</i> isolates.

<p>Similarity coefficients were generated from a similarity matrix calculated with the Jaccard coefficient using SPSS 20.0 software.</p

Molecular and phenotypic characterization of <i>S. hominis</i> blood isolates.

1<p>Neg: biofilm non-producer; Glu: media with 1% glucose; NaCl: media with 3% NaCl.</p>2<p>FOX: cefoxitin test; R: resistant; S: susceptible.</p>3<p>Pos: <i>mecA</i> gene present, Neg: <i>mecA</i> absent.</p>4<p>Neg: not amplified.</p>5<p>SCCmec type III was assigned for <i>S. aureus</i> according to <a href="http://www.sccmec.org/Pages/SCC_TypesEN.html" target="_blank">http://www.sccmec.org/Pages/SCC_TypesEN.html</a>.</p><p>Neg: not amplified, UT: untyped; UT1, UT2 and UT3 types are assigned in this study.</p>6<p>PEN: penicillin; AMP: ampicillin; AUG: amoxicillin-clavulanic acid; ERY: erythromycin; TMP: trimethoprim; CIP: ciprofloxacin; TET: tetracycline; CHL: chloramphenicol; GEN: gentamicin; RIF: rifampin; NIT: nitrofurantoin; CTX: cefotaxime; DAP: daptomycin.</p>*<p>Non-susceptible.</p><p>All isolates were susceptible to vancomycin and linezolid.</p

Microbiological evaluation from extracted tonsils and swab tonsils from all cases.

<p>Microbiological evaluation from extracted tonsils and swab tonsils from all cases.</p

The carriage of interleukin-1B-31*C allele plus <i>Staphylococcus aureus</i> and <i>Haemophilus influenzae</i> increases the risk of recurrent tonsillitis in a Mexican population

<div><p>The aim of the present study was to estimate the relative contribution of immunogenetic and microbiological factors in the development of recurrent tonsillitis in a Mexican population. Patients (n = 138) with recurrent tonsillitis and an indication of tonsillectomy (mean age: 6.05 years ± 3.00; median age: 5 years, female: 58; age range: 1–15 years) and 195 non-related controls older than 18 years and a medical history free of recurrent tonsillitis were included. To evaluate the microbial contribution, tonsil swab samples from both groups and extracted tonsil samples from cases were cultured. Biofilm production of isolated bacteria was measured. To assess the immunogenetic component, DNA from peripheral blood was genotyped for the <i>TNFA-308G/A</i> single-nucleotide polymorphism (SNP) and for the <i>IL1B -31C/T</i> SNP. Normal microbiota, but no pathogens or potential pathogens, were identified from all control sample cultures. The most frequent pathogenic species detected in tonsils from cases were <i>Staphylococcus aureus</i> (48.6%, 67/138) and <i>Haemophilus influenzae</i> (31.9%, 44/138), which were found more frequently in patient samples than in samples from healthy volunteers (<i>P</i> < 0.0001). Importantly, 41/54 (75.9%) <i>S</i>. <i>aureus</i> isolates were biofilm producers (18 weak and 23 strong), whereas 17/25 (68%) <i>H</i>. <i>influenzae</i> isolates were biofilm producers (10 weak, and 7 strong biofilm producers). Patients with at least one copy of the <i>IL1B-31*C</i> allele had a higher risk of recurrent tonsillitis (OR = 4.03; 95% CI = 1.27–14.27; <i>P</i> = 0.013). <i>TNFA-308 G/A</i> alleles were not preferentially distributed among the groups. When considering the presence of <i>IL1B-31*C</i> plus <i>S</i>. <i>aureus</i>, <i>IL1B-31*C</i> plus <i>S</i>. <i>aureus</i> biofilm producer, <i>IL1B-31*C</i> plus <i>H</i>. <i>influenzae</i> or <i>IL1B-31*C</i> plus <i>H</i>. <i>influenzae</i> biofilm producer, the OR tended to infinite. Thus, the presence of <i>IL1B-31*C</i> allele plus the presence of <i>S</i>. <i>aureus</i> and/or <i>H</i>. <i>influenzae</i> could be related to the development of tonsillitis in this particular Mexican population.</p></div

Genotype and allele frequencies of <i>TNFA-308G/A</i> and <i>IL1B-31C/T</i> in recurrent tonsillitis and control patients.

<p>Genotype and allele frequencies of <i>TNFA-308G/A</i> and <i>IL1B-31C/T</i> in recurrent tonsillitis and control patients.</p

Odds ratios (OR) with 95% confidence intervals (CIs) for risk factors.

<p>Odds ratios (OR) with 95% confidence intervals (CIs) for risk factors.</p

Restriction pattern and Southern hybridization of selected plasmids.

<p>(A): Restriction pattern; (B): Southern hybridization; M: Molecular weight marker of 1.5 kb; 1: 15–1327; 2: TT 14–3442 <i>E</i>. <i>cloacae</i>; 3: TT 15–0026; 4: TT 14–3335; 5: TT 14–3337; 6: TT 14–3424; 7: TT 14–3425; 8: TT 15–1363; 9: TT 15–1372. TT represents transconjugants; E.cl represents <i>E</i>. <i>cloacae;</i> E.c represents <i>E</i>. <i>coli;</i> and K.p. represents <i>K</i>. <i>pneumoniae</i>.</p

Characteristics of representative isolates of <i>Enterobacteriaceae</i> harboring <i>bla</i>_NDM-1.

<p>Characteristics of representative isolates of <i>Enterobacteriaceae</i> harboring <i>bla</i>_NDM-1.</p

Distribution of virulence factors in <i>bla</i>_NDM-1 producing <i>K</i>. <i>pneumoniae</i> isolates and carbapenem susceptible isolates.

<p>Distribution of virulence factors in <i>bla</i>_NDM-1 producing <i>K</i>. <i>pneumoniae</i> isolates and carbapenem susceptible isolates.</p

Pulsed-field gel electrophoresis dendrogram and biofilm production of <i>S</i>. <i>hominis</i> isolates.

<p>¹Biofilm production level: OD <0.12 negative, 0.12–0.24 weak and >0.25 strong. Neg: negative. ²All: positive for <i>icaR</i>, <i>icaA</i>, <i>icaD</i>, <i>icaB</i>, and <i>icaC</i>. ³ND non-determinate. ⁴Similarity coefficients were generated from a similarity matrix calculated with the Jaccard coefficient using SPSS 22.0 software.</p