An outbreak in intravenous drug users due to USA300 Latin-American variant community-acquired methicillin-resistant Staphylococcus aureus in France as early as 2007.

Intravenous drug users are at increased risk of Staphylococcus aureus infections. Most cases are related to clones prevalent in the community. We report an outbreak of community-acquired methicillin-resistant Staphylococcus aureus infections that occurred from 2007 to 2009 in intravenous drug users and their close contacts in Northwestern France. Clinical and molecular investigations suggested that the clones were more similar than those usually isolated in the American continent although none of the patients traveled abroad or had contact with individuals who had traveled to the Americas. Then, a retrospective whole genome sequencing and phylogenetic analyses demonstrated that the strains isolated from the first case belong to the USA300 Latin-American variant clone, based on the absence of arginine catabolic mobile element (ACME), and the presence of copper and mercury resistance mobile element (COMER), a distinctive feature of the South American variant. Our study shows genetic evidence for introduction of this clone as early as 2007 in France. This report also illustrates the importance of genome sequencing to finely characterize and monitor the emergence of unexpected S. aureus clones among high-risk populations, especially when living in promiscuity.

Mupirocin/chlorexidine to prevent methicillin-resistant Staphylococcus aureus infections: post hoc analysis of a placebo-controlled, randomized trial using mupirocin/chlorhexidine and polymyxin/tobramycin for the prevention of acquired infections in intubated patients.

PURPOSE: The reduction in acquired infections (AI) due to methicillin-resistant Staphylococcus aureus (MRSA) with the mupirocin/chlorhexidine (M/C) decontamination regimen has not been well studied in intubated patients. We performed post hoc analysis of a prior trial to assess the impact of M/C on MRSA AI and colonization. METHODS: We conducted a multicenter, placebo-controlled, randomized, double-blind study with the primary aim to reduce all-cause AI. The two regimens used [topical polymyxin and tobramycin (P/T), nasal mupirocin with chlorhexidine body wash (M/C), or corresponding placebos for each regimen] were administered according to a 2 × 2 factorial design. Participants were intubated patients in the intensive care units of three French university hospitals. The patients enrolled in the study (n = 515) received either active P/T (n = 130), active M/C (n = 130), both active regimens (n = 129), or placebos only (n = 126) for the period of intubation and an additional 24 h. The incidence and incidence rates (per 1,000 study days) of MRSA AI were assessed. Due to the absence of a statistically significant interaction between the two regimens, analysis was performed at the margins by comparing all patient receiving M/C (n = 259) to all patients not receiving M/C (n = 256), and all patients receiving P/T (n = 259) to all patients not receiving P/T (n = 256). RESULTS: Incidence [odds ratio (OR) 0.39, 95 % confidence interval (CI) (0.16-0.96), P = 0.04] and incidence rates [incidence rate ratio (IRR) 0.41, 95 % CI 0.17-0.97, P = 0.05] of MRSA AI were significantly lower with the use of M/C. We also observed an increase in the incidence (OR 2.50, 95 % CI 1.01-6.15, P = 0.05) and the incidence rate (IRR 2.90, 95 % CI 1.20-8.03, P = 0.03) of MRSA AI with the use of P/T. CONCLUSION: Among our study cohort of intubated patients, the use of M/C significantly reduced MRSA AI.

Use of the quantitative antibiogram method for assessing nosocomial transmission of ESBL-producing Enterobacterales in a French hospital.

BACKGROUND: Extended-spectrum beta-lactamase-producing Enterobacterales (eESBL) have high prevalence in hospitals, but real-time monitoring of nosocomial acquisition through conventional typing methods is challenging. Moreover, patient-to-patient transmission varies between the main species, namely Escherichia coli and Klebsiella pneumoniae, which draws into question the relevance of applying identical preventive measures. AIM: To detect eESBL cross-transmission events (CTEs) using the quantitative antibiogram (QA) method in combination with epidemiological data (combined QA method), and to determine the effectiveness of standard or contact precautions for eESBL species. METHODS: First, a validation set was used to compare the relevance of the combined QA method with a combination of pulsed-field gel electrophoresis and epidemiological data (combined PFGE method). Next, a 4-year retrospective analysis was conducted to detect eESBL CTEs in hospitalized patients. Two species were screened - ESBL E. coli (ESBL-Ec) and ESBL K. pneumoniae (ESBL-Kp). During the study, standard precautions alone were applied to patients with ESBL-Ec, whereas contact precautions were applied for patients with ESBL-Kp. FINDINGS: As a proof of concept, use of the combined QA method and the combined PFGE method for the detection of CTEs gave identical results for E. coli, and similar results for at least 75% of K. pneumoniae. Overall, 722 patients with ESBL-Ec isolates and 280 patients with ESBL-Kp isolates were included in the retrospective analysis. Nine and 23 CTEs were identified for E. coli and K. pneumoniae, respectively, involving 20 (2.7%) and 36 (12.8%) patients, respectively. CONCLUSION: The combined QA method constitutes a rapid tool for epidemiological surveillance to detect CTEs. In the study hospital, standard precautions are sufficient to prevent acquisition of ESBL-Ec, whereas contact precautions must be implemented to prevent acquisition of ESBL-Kp.

Are enterococci playing a role in postoperative peritonitis in critically ill patients?

This prospective non-interventional study is aimed at evaluating the role of enterococci in the postoperative course of postoperative peritonitis (POP) and the predictive factors for isolating Enterococcus spp. All adult patients, hospitalized in intensive care, who had POP between September 2006 and February 2010 were analysed. The patients' baseline clinical characteristics and microbiological and surgical characteristics of the first episode of POP were recorded. The rates of surgical and non-surgical complications and mortality were studied. A total of 139 patients were analysed and Enterococcus spp. were recovered in 61 patients (43%). The presence of enterococci was associated with significantly more intra-abdominal abscesses (26% vs 12%, p=0.025), but did not affect the rate of reoperation or mortality. Antibiotic use before reoperation was the only independent predictive factor for isolating enterococci (OR=2.19, CI95%: 1.02-4.70, p<0.043). Although mortality was not affected by the presence of Enterococcus spp., a higher rate of intra-abdominal abscess was found, suggesting that enterococci play a significant role in postoperative peritonitis, but the need to treat them remains to be determined. Previous antibiotic use before reoperation was a key factor in predicting the subsequent recovery of enterococci.

Clustered cases of infections due to an uncommon methicillin-resistant Staphylococcus aureus originating in a maternity ward.

OBJECTIVE: We aimed to report a community outbreak of an uncommon methicillin-resistant Staphylococcus aureus (MRSA) originating in a maternity ward. PATIENTS AND METHODS: Cases were defined by epidemiological, clinical, and microbiological investigations. Microbiological investigations included phenotypic analysis, molecular typing, and whole-genome sequencing. To control the outbreak, we applied both national recommendations to prevent in-hospital transmission and the French High Council for Public Health guidelines on the management of community-acquired MRSA infections. RESULTS: Between March and July 2016, seven patients with MRSA infections were identified: six skin and soft tissue infections and one pulmonary infection, including six microbiologically confirmed infections. Infections occurred in community settings, but a link with the same maternity ward was found for all patients. All MRSA strains had a t690 spa type, were tetracycline-resistant, and produced Panton-Valentine leukocidin. All isolates belonged to the sequence type 88 (ST88). CONCLUSION: This outbreak highlights the largely underestimated risk of healthcare-associated infections in maternity wards. Healthcare workers should be aware of the importance of standard hygiene precautions and use of alcohol-based hand sanitizers for neonates and mothers.

A portrait of Staphylococcus aureus from the other side of the Mediterranean Sea: molecular characteristics of isolates from Western Algeria.

Algerian hospitals have experienced a dramatic increase in methicillin-resistant Staphylococcus aureus (MRSA) prevalence in recent years. To investigate this phenomenon, we have determined molecular characteristics of 61 methicillin-resistant or -susceptible strains isolated between 2003 and 2007 in Oran Hospital. Susceptible isolates were related to diverse genetic backgrounds, of which clone with sequence type (ST) 8 accounted for most of the samples. Resistance to methicillin was almost limited to two international spreading clones; the most frequent, ST80, contained isolates producing Panton-Valentine leukocidine, with SCCmec type IV. The increase of MRSA prevalence observed in Western Algeria, in outpatients as well as in hospitalized patients, is linked to dissemination of ST80 strains usually considered as community-acquired MRSA.

Factors associated with multidrug-resistant bacteria in secondary peritonitis: impact on antibiotic therapy.

Secondary peritonitis includes community-acquired and nosocomial peritonitis. These intra-abdominal infections have a common pathogenesis but some microbiological differences, particularly with respect to the type of bacteria recovered and the level of antimicrobial susceptibility. This report describes a prospective observational study of 93 consecutive patients with secondary peritonitis during an 11-month period. Community-acquired peritonitis accounted for 44 cases and nosocomial peritonitis for 49 cases (post-operative in 35 cases). Fifteen multidrug-resistant (MDR) bacteria were recovered from 14 patients. In univariate analysis, the presence of MDR bacteria was associated significantly with pre-operative and total hospital lengths of stay, previous use of antimicrobial therapy, and post-operative antimicrobial therapy duration and modifications. A 5-day cut-off in length of hospital stay had the best specificity (58%) and sensitivity (93%) for predicting whether MDR bacteria were present. In multivariate analysis, only a composite variable associating pre-operative hospital length of stay and previous use of antimicrobial therapy was a significant independent risk-factor for infection with MDR bacteria. In conclusion, knowledge of these two factors may provide a more rational basis for selecting initial antimicrobial therapy for patients with secondary peritonitis.

[Suitability of intraoperative autotransfusion]. / Suivi des techniques de récupération de sang en peropératoire.

This work presents the procedure applied by our hospital to assess the quality and security of intra operative autotransfusion. The suitability of the three following variables has to be constantly assessed: performance of the machines to concentrate and wash collected blood, bacterial contamination of processed blood and rate of adverse events. We note that the procedure is applied with participation of medical and nursing staff. Since its setting-up, we note an amelioration of suitable variables.

Esterase electrophoresis compared with biotyping for epidemiological typing of Acinetobacter baumannii strains.

Forty-nine Acinetobacter baumannii strains belonging to three biotypes and isolated from four hospitals were differentiated by electrophoretic typing of their esterases. Six main kinds of esterases were distinguished by their spectra of hydrolytic activity toward seven synthetic substrates. The electrophoretic variations of these enzymes were used to define ten zymotypes among the three biotypes. Esterase electrophoresis appeared to be more sensitive than biotyping, and could represent an additional marker for epidemiological analysis.

Dermonecrotic toxin production by strains of Pasteurella multocida isolated from man.

Ninety-four clinical isolates of Pasteurella multocida of human origin were tested for dermonecrotic toxin (DNT) production by three methods: dermonecrotic test in guinea-pigs, Vero cell culture cytotoxicity and ELISA. The strains were isolated from patients living in a rural area with widespread intensive pig breeding. Six strains were found to be toxigenic by the three tests. A major protein band of Mr 145 Kda corresponding to DNT on immunoblots was demonstrated in extracts from these strains. All were isolated from respiratory tract (diseases 5, healthy carriage 1). The difference between isolates from the respiratory tract and isolates from wounds inflicted by pets was statistically significant with regard to DNT production (p less than 0.02). A possible role of the toxin in pulmonary diseases caused by P. multocida has yet to be established.

Cleavage of immunoglobulin A1, A2 and G by proteases from clinical isolates of Pasteurella multocida.

Several Pasteurella multocida strains were examined for their ability to produce extracellular enzymes that cleave immunoglobulin A and G (Ig A and Ig G) molecules. Two strains isolated from human pulmonary and genital infections produced proteases that cleaved human IgA and IgG, colostral IgA and human myeloma IgA1 and IgA2. Human IgM was not degraded by these enzymes. Examination of cleavage digests showed two main fragments with different electrophoretic mobilities. The two P. multocida strains produced a protease that cleaved IgA and IgG heavy chains outside the hinge region, and differed in this respect from the hinge-cutting proteases of other bacteria. Protease production may be a virulence mechanism for P. multocida strains.

Characterisation of dermonecrotic toxin-producing strains of Pasteurella multocida subsp. multocida isolated from man and swine.

Thirty-six isolates, from man or swine, of Pasteurella multocida subsp. multocida producing (n = 13) or not producing (n = 23) the dermonecrotic toxin (DNT) were studied by numerical analysis, capsular typing and ribotyping. Toxigenic strains were also characterised by restriction fragment length polymorphism (RFLP) of the toxA gene and pulsed-field gel electrophoresis (PFGE). Numerical analysis differentiated the Pasteurella species and subspecies, but did not discriminate between toxigenic and nontoxigenic strains. RFLP demonstrated that toxA was located in a conserved part of the chromosome of all toxigenic strains. Ribotyping provided evidence of a close association between DNT production and one of the six EcoRI ribotypes designated as E2. In contrast, PFGE provided evidence for significant DNA polymorphism amongst the toxigenic strains. Results of phenotypic and genotypic studies suggested that toxigenic strains do not form a clone within the subspecies multocida. No difference was found between toxigenic strains of porcine or human origin by biochemical characterisation, capsular serotyping or genomic typing methods.

Comparative antimicrobial resistance and genomic diversity of Escherichia coli isolated from urinary tract infections in the community and in hospitals.

Well-defined community- and nosocomially-acquired isolates of Escherichia coli responsible for urinary tract infections were studied for their resistance to beta-lactams, quinolones, and co-trimoxazole, antibiotics widely used for treatment of urinary infections. For each strain, an antibiogram was obtained using the Vitek automat, which estimates the minimal inhibitory concentrations of various drugs. Nosocomial strains were significantly more amoxycillin-resistant than community strains (P = 0.01) and were also significantly more resistant to co-trimoxazole (P = 0.025) and first generation quinolones (P = 0.02) than the latter. To determine whether this was due to transmission of strains within the hospital, DNA restriction patterns, established using XbaI enzyme and separation by pulsed-field gel electrophoresis, were compared. Extreme genomic diversity was found among both the community and nosocomial strains. The increased frequency of resistance among nosocomial strains is thus not due to transmission of resistant hospital strains but probably results from the selection of resistant strains from the endogenous flora of patients.

Selective intrapartum anti-bioprophylaxy of group B streptococci infection of neonates: a prospective study in 2454 subsequent deliveries.

OBJECTIVE: To investigate the efficacy of a selective intrapartum prophylaxy of group B streptococci (GBS) infection of the neonates. STUDY DESIGN: A prospective protocol of universal antepartum screening of GBS and selective intrapartum treatment from the 1st February 1994 to the 31st December 1995, on 2454 subsequent deliveries was designed. Our policy included: (1) antepartum screening as soon as possible after 28 weeks by a single vaginal and perianal sample for culture; (2) intrapartum recognition of one condition of high risk of fetal contamination during labor (these conditions included: a temperature of 38 degrees C during labor, rupture of membranes for more than 12 h or prolonged labor for more than 12 h with rupture of membranes, prematurity, twins, maternal diabetes, previous pregnancy with GBS infection of the neonate); and (3) intrapartum anti-bioprophylaxy (amoxicillin) for women with positive screening during pregnancy and one condition of high risk of fetal contamination during labor. We studied the outcome of neonates during this period to look for immediate GBS severe infection of the neonates in the form of bacteraemia or meningitis and compared the results with the rate of neonatal infection before this protocol (4.5/1000 live births in 1993). RESULTS: We noted that 11% of pregnant women were carriers, 25% of which led to antibiotic chemoprophylaxis during the labor. We noticed four cases of neonatal bacteraemia of GBS. One case arose from the group of carriers (but no condition of risk of fetal contamination during the labor and no chemoprophylaxy). The three other cases were from women with a negative antepartum screening. There was no case of meningitis and all four babies were in good health at day 10 of life. Comparing with results prior to the study, we noticed that the rate of neonatal bacteraemia dropped from 4.5 to 1.6 per 1000 livebirths (P < 0.0001). CONCLUSION: This protocol of intrapartum anti-bioprophylaxy significantly decreases the rate of GBS neonatal sepsis. We propose to improve the efficacy of this prevention program, especially with regard to the method of antepartum screening of pregnant women colonized with GBS.

Characterization of Pasteurella spp. strains isolated from human infections.

This report describes the distribution of species and capsular groups in a collection of 143 strains of Pasteurella recovered from human patients. The organism isolated most frequently was Pasteurella multocida subsp. multocida. As in animals, most of the group A strains were recovered from the respiratory tract. The distribution of species in relation to the animal source suggests that P. multocida subsp. multocida is more infective than other Pasteurella species or subspecies for man.

[Infections and utilization of antibiotics in the hospital, results from a prevalence survey in 1986]. / Infections et usage des antibiotiques à l'hôpital, résultats d'une enquête de prévalence en 1986.

To estimate the rate of infectious diseases and the efficiency of medical care in our hospital, we conducted a prevalence survey of both infections and antibiotic use on 588 inpatients. Results showed that 125 patients (21% of the total) had infections; of these, 56 had nosocomial infections. A third of the patients had been receiving antimicrobial drugs; among them, 30% were receiving the drugs for prophylactic reasons. A misuse in the prophylaxis of infections was determined, particularly in the duration of treatment. The study demonstrated that an effective infection-control program and an antibiotic policy are required in our hospital.

Continuous ambulatory peritoneal dialysis: evaluation of three new culture methods.

Out of 900 dialysates analysed over 15 months at the Rennes Regional Hospital, 116 cloudy specimens with a leucocyte count of more than 100/mm3 were studied. Three methods of laboratory diagnosis based on physical or chemical disruption of leucocytes were evaluated: saponin incorporated in the agar medium, sonication, and the Isolator lysis centrifugation system. Sensitivity was improved (52%) for the three methods combined compared with the standard method (37%). The Isolator system (51%, P < 0.05) gave the best results. Direct microscopic examination nevertheless remains essential for its indicative value (sensitivity 33% of positive dialysates). The leucocyte count was correlated with the percentage of culture positivity (43% from 100-200/mm3 compared with 62% from 500-1000/mm3); 80% of organisms were Gram-positive bacteria and most were coagulase-negative staphylococci. Opportunistic pathogens such as Corynebacterium jeikeium were frequently isolated.

[Isolation of Escherichia vulneris in drinking water]. / Isolement de Escherichia vulneris dans l'eau d'alimentation.

Over a 2-year period, we performed 33 bacteriological controls of drinking water supplied by refrigerated fountains located in a nursing home. Amongst 24 strains of gram-negative bacilli isolated from 16 samples. 10 were identified as belonging to the species Escherichia vulneris. Viable bacterial counts were always less than 10 ufc/100 ml. During the same period no clinical isolate of E. vulneris was recovered from the nursing home. The signification of E. vulneris in drinking water is unknown. However, considering that E. vulneris has been implicated as cause of various infections, its presence in potable water supply systems would seem to be a potential risk factor for severely immunocompromised patients.

[Pasteurelloses]. / Les pasteurelloses.

According to the genetic relationships among Gram-negative bacilli the genus Pasteurella is included with the genus Haemophilus and the genus Acinobacillus within the family Pasteurellacae. Pasteurella multocida, the type species, is responsible for the majority of human Pasteurella infections. P. multocida is a member of the normal flora in the upper respiratory tract of many mammals or birds. It causes sporadic or epidemic diseases among different animal species, particularly pneumonia and atrophic rhinitis in swine in intensive breeding stations. The most common human infection with P. multocida is a local cellulitis following dog or cat bites and scratches. Serious local complications are sometimes responsible for prolonged disability. The respiratory tract is the second human source of P. multocida isolates. The frequency of recovery of P. multocida from oropharynx of apparently healthy pig breeders suggests that respiratory pasteurellosis could be an occupational disease. The mechanisms of virulence of P. multocida are unclear. Several factors are involved: capsules preventing phagocytosis, a dermonecrotic toxin causing experimental atrophic rhinitis, hyaluronidase, neuraminidase and proteases. Penicillin is considered to be the drug of choice for Pasteurella infection. Tetracyclin is efficient for bites but has no bactericidal effect. Oxacillin, first-generation cephalosporins, macrolides and aminoglycosides have poor activities. In the case of beta-lactamase producing strains a bactericidal effect could be achieved with fluoroquinolones or third generation cephalosporins.