Incidence, clinical presentation, and antimicrobial resistance trends in Salmonella and Shigella infections from children in Yucatan, Mexico

Background: Salmonella and Shigella cause significant morbidity and mortality among children worldwide. Increased antimicrobial resistance results in greater burden of disease. Methods: From 2005 to 2011, Salmonella and Shigella isolates collected from ill children at a major hospital in Yucatan, Mexico, were subjected to serotyping and antimicrobial susceptibility testing by disk diffusion and agar dilution. The identification of blaCTX, blaCMY, blaSHV, blaTEM, and blaOXA and qnr resistance genes was conducted by PCR and sequencing. Results: Among 2344 children with acute gastroenteritis, salmonellosis decreased from 17.7% in 2005 to 11.2% in 2011 (p<0.001). In contrast, shigellosis increased from 8.3% in 2010 to 12.1% in 2011. Compared to children with Salmonella, those with Shigella had significantly more bloody stools (59% vs 36%, p<0.001), dehydration (27% vs 15%, p=0.031), and seizures (11% vs 3%, p=0.03). In Salmonella (n=365), there was a significant decrease in resistance to ampicillin (43% to 16%, p<0.001), trimethoprim-sulfamethoxazole (44% to 26%, p=0.014), and extended-spectrum cephalosporins (27% to 10%, p=0.009). Reduced susceptibility to ciprofloxacin in Salmonella rose from 30% to 41% (p<0.001). All ceftriaxone-resistant isolates harbored the blaCMY-2 gene. qnr genes were found in 42 (36%) of the 117 Salmonella isolates with a ciprofloxacin MIC ≥ 0.125 µg/ml. Four were qnrA1 and 38 were qnrB19. Resistance to ampicillin (40%) and trimethoprim-sulfamethoxazole (58%) was common in Shigella (n=218), but isolates remained fully susceptible to ceftriaxone and ciprofloxacin. Conclusions:Illness from Salmonella has decreased while severe Shigella infections have increased among children with gastroenteritis in the Yucatan Peninsula. While Shigella resistance to clinically important antibiotics remained unchanged, resistance to most of these, except ciprofloxacin, declined in Salmonella. blaCMY-2 and qnr genes are common in Salmonella isolates

Construct and expression of recombinant domains I/II of dengue virus- 2 and its efficacy to evaluate immune response in endemic area: possible use in prognosis

The envelope (E) protein from DENV, contain three functional and structural domains (DI, DII and DIII). Some studies suggest that neutralizing antibodies during natural DENV infection are predominantly against DI and DII, in contrast, low proportion of the antibodies were against DIII. Thus it is necessary to establish the proportion of human antibodies against DENV E protein that bind to DI and DII during the normal course of infection; as an indicator of the quality of the antibody response and to further design new vaccine candidates for DENV. The aim of this study was to express recombinant proteins harboring a 240-aminoacid fragment of the E protein from DI and DII of DENV serotypes 2 and 3 in a eukaryotic S2 system. Further, we evaluate the antibodies against these antigens in samples from patients in acute phase of DF or DHF and compare it with the response of samples from healthy individuals from the same endemic areas and samples from healthy individuals from a non-endemic area (EA and NEA, respectively). These results suggest that the presence of antibodies against rEDI/DII might be used to identify patients at risk for severe disease

Diarrheagenic <i>Escherichia coli</i> Carrying Supplementary Virulence Genes Are an Important Cause of Moderate to Severe Diarrhoeal Disease in Mexico

<div><p>Diarrheagenic <i>Escherichia coli</i> (DEC) cause acute and persistent diarrhoea worldwide, but little is known about their epidemiology in Mexico. We determined the prevalence of bacterial enteropathogens in 831 children with acute diarrhoea over a four-year period in Yucatan, Mexico. Six DEC supplementary virulence genes (SVG), mainly associated with enteroaggregative <i>E</i>. <i>coli</i> (EAEC), were sought in 3100 <i>E</i>. <i>coli</i> isolates. DEC was the most common bacterial enteropathogen (28%), surpassing <i>Salmonella</i> (12%) and <i>Shigella</i> (9%). Predominant DEC groups were diffusely adherent <i>E</i>. <i>coli</i> (DAEC) (35%), EAEC (24%), and enteropathogenic <i>E</i>. <i>coli</i> (EPEC) (19%). Among children with DEC infections, 14% had severe illness mainly caused by EPEC (26%) and DAEC (18%); 30% had moderate diarrhoea mainly caused by DAEC (36%), mixed DEC infections (33%) and EAEC (32%). DAEC was most prevalent during spring, while ETEC, EAEC and EPEC predominated in summer. EAEC was more frequent in children 6–24 months old than in those younger than 6 months of age (P = 0.008, OR = 4.2, 95% CI, 1.3–13.9). The presence of SVG dispersin, (<i>aatA</i>), dispersin-translocator (<i>aatA</i>), enteroaggregative heat-stable toxin 1 (<i>astA</i>), plasmid encoded toxin (<i>pet</i>), cytolethal distending toxin (<i>cdt</i>) was higher in DEC than non-DEC strains, (36% vs 26%, P <0.0001, OR = 1.5, 95% CI, 1.3–1.8). 98% of EAEC-infected children harboured strains with SVG; 85% carried the <i>aap-aatA</i> gene combination, and 33% of these also carried <i>astA</i>. 28% of both EPEC and ETEC, and 6% of DAEC patients had strains with SVG. 54% of EPEC patients carried <i>pet</i>-positive strains alone or in combination with <i>astA</i>; only this DEC group harboured <i>cdt</i>-positive isolates. All ETEC patients carried <i>astA</i>- or <i>astA-aap</i>-positive strains. <i>astA</i> and <i>aap</i> were the most common SVG in DAEC (3% and 2%) and non-DEC strains (21% and 13%). DEC carrying SVG are an important cause of moderate to severe bacterial diarrhoea in Mexican children.</p></div

Phenotypic and genotypic characteristics used to identify of diarrheagenic <i>Escherichia coli</i> (DEC) groups in this study.

<p>ETEC: enterotoxigenic <i>E</i>. <i>coli</i>,</p><p>tEPEC: typical enteropathogenic <i>E</i>. <i>coli</i>,</p><p>aEPEC: atypical enteropathogenic <i>E</i>. <i>coli</i>,</p><p>EAEC: enteroaggregative <i>E</i>. <i>coli</i>,</p><p>DAEC: diffusely adherent <i>E</i>. <i>coli</i>.</p><p>LEE: locus of enterocyte effacement,</p><p>BFP: bundle-forming pilus;</p><p>EAF: EPEC adherence factor plasmid, <i>eaeA</i> and <i>afaC</i>: genes encoding for intimin and Afa fimbria usher, respectively.</p><p>Phenotypic and genotypic characteristics used to identify of diarrheagenic <i>Escherichia coli</i> (DEC) groups in this study.</p

Distribution of supplementary virulence genes (SVG) among Diarrheagenic <i>E</i>. <i>coli</i> (DEC) and non-DEC strains isolated from children with moderate to severe acute diarrhoea from Yucatan, Mexico.

<p>ETEC: enterotoxigenic <i>E</i>. <i>coli</i>,</p><p>tEPEC: typical enteropathogenic <i>E</i>. <i>coli</i>,</p><p>aEPEC: atypical enteropathogenic <i>E</i>. <i>coli</i>,</p><p>EAEC: enteroaggregative <i>E</i>. <i>coli</i>,</p><p>DAEC: diffusely adherent <i>E</i>. <i>coli</i>.</p><p><i>aap</i> and <i>aatA</i>: genes encoding for dispersin and its translocator,</p><p><i>astA</i>, <i>pet</i> and <i>cdt</i>: genes encoding for enteroaggregative heat-stable toxin 1, plasmid encoded toxin and cytolethal distending toxin, respectively.</p><p>Distribution of supplementary virulence genes (SVG) among Diarrheagenic <i>E</i>. <i>coli</i> (DEC) and non-DEC strains isolated from children with moderate to severe acute diarrhoea from Yucatan, Mexico.</p

Severity of disease and length of hospitalization in children by DEC group.

<p>¹Refers to percentage of patients for each DEC group and total DEC infections</p><p>Severity of disease and length of hospitalization in children by DEC group.</p

Mycobacterial disease in patients with chronic granulomatous disease: A retrospective analysis of 71 cases

International audienceBackground : Chronic granulomatous disease (CGD) is a rare primary immunodeficiency caused by inborn errors of the phagocyte nicotinamide adenine dinucleotide phosphate oxidase complex. From the first year of life onward, most affected patients display multiple, severe, and recurrent infections caused by bacteria and fungi. Mycobacterial infections have also been reported in some patients.Objective : Our objective was to assess the effect of mycobacterial disease in patients with CGD.Methods : We analyzed retrospectively the clinical features of mycobacterial disease in 71 patients with CGD. Tuberculosis and BCG disease were diagnosed on the basis of microbiological, pathological, and/or clinical criteria.Results : Thirty-one (44%) patients had tuberculosis, and 53 (75%) presented with adverse effects of BCG vaccination; 13 (18%) had both tuberculosis and BCG infections. None of these patients displayed clinical disease caused by environmental mycobacteria, Mycobacterium leprae, or Mycobacterium ulcerans. Most patients (76%) also had other pyogenic and fungal infections, but 24% presented solely with mycobacterial disease. Most patients presented a single localized episode of mycobacterial disease (37%), but recurrence (18%), disseminated disease (27%), and even death (18%) were also observed. One common feature in these patients was an early age at presentation for BCG disease. Mycobacterial disease was the first clinical manifestation of CGD in 60% of these patients.Conclusion : Mycobacterial disease is relatively common in patients with CGD living in countries in which tuberculosis is endemic, BCG vaccine is mandatory, or both. Adverse reactions to BCG and severe forms of tuberculosis should lead to a suspicion of CGD. BCG vaccine is contraindicated in patients with CGD