Staphylococus aureus ST398: a medical paradigm of the 21st century

The potential for nasal and pharyngeal colonization by the bacterial species, Staphylococcus aureus, has increased over the last decade, particularly among pigs. The frequency of Methicillin-Resistant Staphylococcus aureus (MRSA) strains varies, but they constitute a non-negligible risk for those involved in pig production, i.e. pig-keepers, veterinarians, and slaughterhouse workers. Molecular identification by MLST (Multi Locus Sequence Typing) of isolates originally non-typeable (NT) by Pulse Field Electrophoresis clearly showed the predominance in Europe, North America and Asia of the ST398 (CC398) type. So far, this strain does not appear to be highly resistant to antibiotics, with the exception of tetracyclines, and perhaps macrolides, nor does it produce the virulence factors generally associated with CA-MRSA, such as the Panton-Valentine leukocidin. Various types of human infection were reported in several European countries, producing skin and mucous membranes, lungs, endocardium and bacteremic infections. Some experts suggest that, despite their low riskL’espèce Staphylococcus aureus a montré, au cours de ces dernières années, un fort pouvoir de colonisation naso-pharyngée, en particulier chez le porc. Le pourcentage de souches résistantes intrinsèques ou SAMR est variable mais le risque de colonisation est non négligeable pour les professionnels de la filière de production porcine, tels que les porchers, vétérinaires, employés d’abattoir. L’identification moléculaire par la technique de Multi Locus Sequence Typing (MLST) de souches initialement non typables (NT) par l’électrophorèse en champ pulsé indique la prédominance, aussi bien en Europe, en Amérique du Nord qu’en Asie, du type ST398 (ou CC398). Cette souche est encore peu résistante aux antibiotiques, à l’exception des tétracyclines, voire des macrolides et ne produit pas les facteurs de virulence rapportés habituellement chez le CA-MRSA, tels que la leucocidine de Panton- Valentine. Divers types d’infection sont maintenant rapportés chez l’homme dans plusieurs pays européens : infections cutanéo-muqueuses, pulmonaires, bactériémiques et endocardites. Des spécialistes évoquent, pour ces souches d’origine animale (LA pour Lifestock-Associated), l’éventualité « d’une nouvelle zoonose » malgré leur faible diffusion chez l’homme

Rapid detection of glycopeptide-resistant enterococci: impact on decision-making and costs.

International audienceBACKGROUND: According to French national recommendations, the detection of a patient colonized with glycopeptide-resistant enterococci (GRE) leads to interruption of new admissions and transfer of contact patients (CPs) to another unit or healthcare facility, with weekly screening of CPs. FINDINGS: We evaluated the medical and economic impact of a pragmatic adaptation of national guidelines associated with a real-time PCR (RTP) (Cepheid XpertTM vanA/vanB) as part of the strategy for controlling GRE spread in two medical wards. Screening was previously performed using chromogenic selective medium (CSM). Turn around time (TAT), costs of tests and cost of missed patient days were prospectively collected. In February 2012, the identification of GRE in one patient in the diabetology ward led to the screening of 31 CPs using CSM; one secondary case was identified in a CP already transferred to the Nephrology ward. Awaiting the results of SCM (median TAT, 70.5 h), 41 potential patient days were missed, due to interruption of admissions. The overall cost (screening tests + missing patient.days) was estimated at 14, 302.20 [euro sign]. The secondary case led to screening of 22 CPs in the Nephrology ward using RTP. Because of a short median TAT of 4.6 h, we did not interrupt admissions and patients' transfers. Among 22 CPs, 19 (86%) were negative for vanA, 2 were positive for vanB and 3 had invalid results needing CSM. The overall cost of the strategy was estimated at 870.40 [euro sign] (cost of screening tests only), without missing patient days. CONCLUSION: The rapid PCR test for vanA-positive GRE detection both allowed rapid decision about the best infection control strategy and prevented loss of income due to discontinuation of patient transfers and admissions

Antibacterial Resistance, Wayampis Amerindians, French Guyana

Drug resistance in fecal bacteria was high in Wayampis Amerindians who did not take antibacterial agents and were not hospitalized for 1 year. In the Wayampis Amerindians, an isolated traditional community in French Guyana, antibacterial use was 0.64 treatments per person per year. Hospitalization rate was 6.1% per year. Antibacterial drug–resistant bacteria can spread in persons who are not taking antibacterial agents

Prevalence, Risk Factors, and Genetic Characterization of Extended-Spectrum Beta-Lactamase Escherichia coli Isolated From Healthy Pregnant Women in Madagascar

Antimicrobial resistance is a major public health concern worldwide affecting humans, animals and the environment. However, data is lacking especially in developing countries. Thus, the World Health Organization developed a One-Health surveillance project called Tricycle focusing on the prevalence of ESBL-producing Escherichia coli in humans, animals, and the environment. Here we present the first results of the human community component of Tricycle in Madagascar. From July 2018 to April 2019, rectal swabs from 492 pregnant women from Antananarivo, Mahajanga, Ambatondrazaka, and Toamasina were tested for ESBL-E. coli carriage. Demographic, sociological and environmental risk factors were investigated, and E. coli isolates were characterized (antibiotic susceptibility, resistance and virulence genes, plasmids, and genomic diversity). ESBL-E. coli prevalence carriage in pregnant women was 34% varying from 12% (Toamasina) to 65% (Ambatondrazaka). The main risk factor associated with ESBL-E. coli carriage was the rainy season (OR = 2.9, 95% CI 1.3–5.6, p = 0.009). Whole genome sequencing was performed on 168 isolates from 144 participants. bla(CTX–M–15) was the most frequent ESBL gene (86%). One isolate was resistant to carbapenems and carried the bla(NDM–5) gene. Most isolates belonged to commensalism associated phylogenetic groups A, B1, and C (90%) and marginally to extra-intestinal virulence associated phylogenetic groups B2, D and F (10%). Multi locus sequence typing showed 67 different sequence types gathered in 17 clonal complexes (STc), the most frequent being STc10/phylogroup A (35%), followed distantly by the emerging STc155/phylogroup B1 (7%), STc38/phylogroup D (4%) and STc131/phylogroup B2 (3%). While a wide diversity of clones has been observed, SNP analysis revealed several genetically close isolates (n = 34/168) which suggests human-to-human transmissions. IncY plasmids were found with an unusual prevalence (23%), all carrying a bla(CTX–M–15). Most of them (85%) showed substantial homology (≥85%) suggesting a dissemination of IncY ESBL plasmids in Madagascar. This large-scale study reveals a high prevalence of ESBL-E. coli among pregnant women in four cities in Madagascar associated with warmth and rainfall. It shows the great diversity of E. coli disseminating throughout the country but also transmission of specific clones and spread of plasmids. This highlights the urgent need of public-health interventions to control antibiotic resistance in the country

Influence de l'environnement sur le portage nasal et la diversité de Staphylococcus aureus sensible et résistant à la méticilline

Staphylococcus aureus est un des principaux pathogènes isolés en médecine humaine. Il est par ailleurs retrouvé dans la flore commensale de près d un quart de la population. Au cours des années, S. aureus a acquis de multiples résistances dont la résistance à la méticilline. Le S. aureus résistant à la méticilline (SARM) est aujourd hui la première bactérie multirésistante isolée à l hôpital. Les travaux présentés dans cette thèse ont cherché à étudier le portage nasal de S. aureus sensible ou résistant à la méticilline chez différentes populations exposées à des environnements particuliers : professionnels (éleveurs de porcs, étudiants en soins infirmiers) ou hospitaliers (patients hospitalisés). La diversité des souches circulant au sein de ces environnements a également été explorée.Staphylococcus aureus is one of the most important pathogen in human infection diseases. S. aureus is also a bacteria present in commensal flora of about a quarter of the population. For years, S. aureus has acquired antibiotic resistances traits of various clinical relevance, of which methicillin resistance might be the most important. Methicillin-resistant S. aureus (MRSA) is the first multiresistant bacteria isolated in hospitalised patients. The studies presented in this PhD Thesis analysed the nasal carriage of methicillin-susceptible or resistant S. aureus in different populations exposed to contrasted environments : professional (pig farmers, nursing students) or hospital (hospitalized patients). The genetic diversity of strains circulating in these environments was also investigated.CHATENAY M.-PARIS 11-BU Pharma. (920192101) / SudocSudocFranceF

La résistance aux antibiotiques en milieu naturel

À la suite d’un précédent projet (ERAES), il s’agissait de tirer avantage du terrain particulier constitué par le village amérindien de Trois-Sauts (Guyane), pour étudier l’impact de la pression de sélection antibiotique sur l’écologie et la résistance de trois espèces microbiennes potentiellement pathogènes pour l’Homme, à savoir Escherichia coli, Staphylococcus aureus et Candida albicans

Emergence de la résistance aux carbapénèmes chez les bacilles à Gram négatif de la flore intestinale des patients hospitalisés en réanimation

PARIS-BIUP (751062107) / SudocSudocFranceF

Successful treatment of meningococcal bacteremia using oral doxycycline: A case report

International audienceWe report the case of an 18-year-old immunocompetent man who presented to the hospital with fever, headaches, and arthromyalgia, which progressed to include an erythematous rash. He had a history of a tick bite 72 h earlier. The diagnosis of rickettsial infection was suspected and a course of doxycycline was initiated for a total of 5 days. His evolution was rapidly favorable under treatment, with resolution of the symptoms within 24 h. Blood cultures came back positive for Neisseria meningitidis serotype B, indicating an authentic purpura fulminans. Purpura fulminans is a medical emergency, a syndrome of intravascular thrombosis characterized by a very rapid evolution that requires early recognition and specific treatment. It is commonly described in the young and healthy patient and has high mortality and morbidity. Common bacteria mainly associated with purpura fulminans are Meningococcus spp., Pneumococcus spp., and Staphylococcus spp