Linear growth delay (stunting) affects roughly 155 million children under the age of 5 years worldwide. Treatment has been limited by a lack of understanding of the underlying pathophysiological mechanisms. Stunting is most likely associated with changes in the microbial community of the small intestine, a compartment vital for digestion and nutrient absorption. Efforts to better understand the pathophysiology have been hampered by difficulty of access to small intestinal fluids. Here, we describe the microbial community found in the upper gastrointestinal tract of stunted children aged 2-5 y living in sub-Saharan Africa. We studied 46 duodenal and 57 gastric samples from stunted children, as well as 404 fecal samples from stunted and nonstunted children living in Bangui, Central African Republic, and in Antananarivo, Madagascar, using 16S Illumina Amplicon sequencing and semiquantitative culture methods. The vast majority of the stunted children showed small intestinal bacterial overgrowth dominated by bacteria that normally reside in the oropharyngeal cavity. There was an overrepresentation of oral bacteria in fecal samples of stunted children, opening the way for developing noninvasive diagnostic markers. In addition, sp. and sp. were found to be more prevalent in stunted children, while , well-known butyrate producers, were reduced. Our data suggest that stunting is associated with a microbiome "decompartmentalization" of the gastrointestinal tract characterized by an increased presence of oropharyngeal bacteria from the stomach to the colon, hence challenging the current view of stunting arising solely as a consequence of small intestine overstimulation through recurrent infections by enteric pathogens.
Antibiotic treatment is not required in cases of Salmonella enterica gastroenteritis but is essential in cases of enteric fever or invasive salmonellosis or in immunocompromised patients. Although fluoroquinolones and extended-spectrum cephalosporins are the drugs of choice to treat invasive Salmonella , resistance to these antibiotics is increasing worldwide. During the period 2000 to 2003, 90 Salmonella enterica serovar Virchow poultry and poultry product isolates and 11 serovar Virchow human isolates were found to produce an extended-spectrum β-lactamase, CTX-M-2, concomitantly with a TEM-1 β-lactamase. The bla CTX-M-2 gene was located on a large conjugative plasmid (>100 kb). Pulsed-field gel electrophoresis indicated a clonal relationship between the poultry and human isolates. All these isolates displayed additional resistance to trimethoprim-sulfamethoxazole and tetracycline as well as a reduced susceptibility to ciprofloxacin (MICs of between 0.5 and 1 μg/ml). CTX-M-2-producing Salmonella with a reduced susceptibility to fluoroquinolones constitutes a major concern, since such strains could disseminate on a large scale and jeopardize classical antibiotic therapy in immunocompromised patients.
In the present study, a collection of 187 Enterococcus food isolates mainly originating from European cheeses were studied for the phenotypic and genotypic assessment of tetracycline (TC) resistance. A total of 45 isolates (24%) encompassing the species Enterococcus faecalis (n ؍ 33), E. durans (n ؍ 7), E. faecium (n ؍ 3), E. casseliflavus (n ؍ 1), and E. gallinarum (n ؍ 1) displayed phenotypic resistance to TC with MIC ranges of 16 to 256 g/ml. Eight of these strains exhibited multiresistance to TC, erythromycin, and chloramphenicol. By PCR detection, TC resistance could be linked to the presence of the tet(M) (n ؍ 43), tet(L) (n ؍ 16), and tet(S) (n ؍ 1) genes. In 15 isolates, including all of those for which the MIC was 256 g/ml, both tet(M) and tet(L) were found. Furthermore, all tet(M)-containing enterococci also harbored a member of the Tn916-Tn1545 conjugative transposon family, of which 12 erythromycin-resistant isolates also contained the erm(B) gene. Filter mating experiments revealed that 10 E. faecalis isolates, 3 E. durans isolates, and 1 E. faecium isolate could transfer either tet(M), tet(L), or both of these genes to E. faecalis recipient strain JH2-2. In most cases in which only tet(M) was transferred, no detectable plasmids were acquired by JH2-2 but instead all transconjugants contained a member of the Tn916-Tn1545 family. Sequencing analysis of PCR amplicons and evolutionary modeling showed that a subset of the transferable tet(M) genes belonged to four sequence homology groups (SHGs) showing an internal homology of >99.6%. Two of these SHGs contained tet(M) mosaic structures previously found in Tn916 elements and on Lactobacillus and Neisseria plasmids, respectively, whereas the other two SHGs probably represent new phylogenetic lineages of this gene.As lactic acid bacteria, enterococci are natural inhabitants of the gastrointestinal systems of mammals, but they are also known to occur in soil and fecally polluted surface waters and on plants and vegetables (26,31,35). Because of their high prevalence in the gastrointestinal tracts of many food animals, it is often unavoidable that these organisms enter the human food chain via contamination of raw milk or raw meat. For many years, the presence of enterococci in foods has been highly controversial. On the one hand, Enterococcus strains can harbor specific biochemical traits that are essential in the manufacturing of various fermented milk products, and some strains are technologically exploited as functional starters or probiotics (12, 17). On the other hand, enterococci have also been implicated in the spoilage of processed meats (14, 51) and include strains that have been recognized as emerging human pathogens mostly in nosocomial but also in community-acquired infections (for a review, see reference 29).Triggered by the apparent duality between their beneficial and harmful properties, a lot of research has focused on the potential role of food enterococci as reservoirs and/or vehicles of antibiotic resistance (AR) and viru...
Laparoscopic surgery for gastroesophageal reflux disease has replaced the open approach in several institutions, and it is likely to become the "standard" for treatment in the near future. Members of five European surgical centers with extensive experience in pathophysiological research, diagnostic testing, and conventional surgery for esophageal disease met after five years of experience in using laparoscopic antireflux surgery, and established a plan to evaluate the potential for consensus among the centers involved in the surgical management of the disease. The consensus process started with a pathophysiological assessment of the reporting requirements for diagnostic workup. To allow a thorough appreciation of the surgical techniques used by all the participants, experience was exchanged in collaborative operations in an experimental surgical laboratory. It was concluded that the pathophysiological background to the disease is multifactorial, as many publications have shown in recent years. The group's meetings and discussions established a consensus list for the preoperative assessment of patients suspected of having gastroesophageal reflux disease, as well as a common list of operative techniques for successful antireflux surgery.
Following characterisation by phenotypic tests and ampli®ed ribosomal DNA restriction analysis (ARDRA), 50 tetracycline-resistant (MIC > 16 mg=L) Acinetobacter strains from clinical (n 35) and aquatic (n 15) samples were analysed by PCR for tetracycline resistance (Tet) determinants of classes A±E. All the clinical strains were A. baumannii; most (33 of 35) had Tet A (n 16) or B (n 17) determinants, and only two did not yield amplicons with primers for any of the ®ve tetracycline resistance determinants. The aquatic strains belonged to genomic species other than A. baumannii, and most (12 of 15) did not contain determinants Tet A±E. Strains negative for Tet A±E were also negative for Tet G and M; further analysis of two aquatic strains with speci®c primers for Tet O and Tet Y and degenerate primers for Tet M-S-O-P(B)-Q also showed negative results. Transfer of tetracycline resistance was tested for 20 strains with three aquatic Acinetobacter strains and Escherichia coli K-12 as recipients. Transfer of resistance was demonstrated between aquatic strains from distinct ecological niches, but not from clinical to aquatic strains, nor from any Acinetobacter strain to E. coli K-12. Most transconjugants acquired multiple relatively small plasmids (< 36 kb). Transfer did not occur when DNA from the donor strains was added to the recipient cultures and was not affected by deoxyribonuclease I, suggesting a conjugative mechanism. It is concluded that Tet A and B are widespread among tetracycline-resistant A. baumannii strains of clinical origin, but unknown genetic determinants are responsible for most tetracycline resistance among aquatic Acinetobacter spp. These differences, together with the inability of clinical strains to transfer tetracycline resistance in vitro to aquatic strains, contra-indicate any important¯ow of tetracycline resistance genes between clinical and aquatic acinetobacter populations.
SummaryObjectivesNeisseria meningitidis, together with the non-pathogenic Neisseria species (NPNs), are members of the complex microbiota of the human pharynx. This paper investigates the influence of NPNs on the epidemiology of meningococcal infection.MethodsNeisseria isolates were collected during 18 surveys conducted in six countries in the African meningitis belt between 2010 and 2012 and characterized at the rplF locus to determine species and at the variable region of the fetA antigen gene. Prevalence and risk factors for carriage were analyzed.ResultsA total of 4694 isolates of Neisseria were obtained from 46,034 pharyngeal swabs, a carriage prevalence of 10.2% (95% CI, 9.8–10.5). Five Neisseria species were identified, the most prevalent NPN being Neisseria lactamica. Six hundred and thirty-six combinations of rplF/fetA_VR alleles were identified, each defined as a Neisseria strain type. There was an inverse relationship between carriage of N. meningitidis and of NPNs by age group, gender and season, whereas carriage of both N. meningitidis and NPNs was negatively associated with a recent history of meningococcal vaccination.ConclusionVariations in the prevalence of NPNs by time, place and genetic type may contribute to the particular epidemiology of meningococcal disease in the African meningitis belt.
Antibiotic misuse in lower- and middle-income countries (LMICs) contributes to the development of antibiotic resistance that can disseminate globally. Strategies specific to LMICs that seek to reduce antibiotic misuse by humans, but simultaneously improve antibiotic access, have been proposed. However, most approaches to date have not considered the growing impact of animal and environmental reservoirs of antibiotic resistance, which threaten to exacerbate the antibiotic resistance crisis in LMICs. In particular, current strategies do not prioritize the impacts of increased antibiotic use for terrestrial food-animal and aquaculture production, inadequate food safety, and widespread environmental pollution. Here, we propose new approaches that address emerging, One Health challenges.
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