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1.
J Gynecol Obstet Hum Reprod ; 52(5): 102569, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36878392

RESUMO

BACKGROUND: The occurrence of COVID-19 during the pregnancy can cause several negative maternal and neonatal outcomes. Nasopharyngeal viral load is associated with inflammatory markers and might influence the disease severity in non-pregnant patients, but there are no data about the relationship between viral load and perinatal outcomes in pregnant patients. OBJECTIVE: To investigate the hypothesis that nasopharyngeal SARS-CoV-2 load (estimated with real-time polymerase chain reaction delta cycle (ΔCt), measured in hospital clinical laboratories) is associated with perinatal outcomes, when COVID-19 is diagnosed in the third trimester of pregnancy. STUDY DESIGN: International, retrospective, observational, multi-center, cohort study enrolling 390 women (393 neonates, three pairs of twins), analyzed with multivariate generalized linear models with skewed distributions (gamma) and identity link. The analyses were conducted for the whole population and then followed by a subgroup analysis according to the clinical severity of maternal COVID-19. RESULTS: The estimated viral load in maternal nasopharynx is not significantly associated with gestational age at birth (adjusted B: -0.008 (95%CI: -0.04; 0.02); p = 0.889), birth weight (adjusted B: 4.29 (95%CI: -25; 35); p = 0.889), weight Z-score (adjusted B: -0.01 (95%CI: -0.03; 1); p = 0.336), 5' Apgar scores (adjusted B: -0. -9.8e-4 (95%CI: -0.01; 0.01); p = 0.889), prematurity (adjusted OR: -0.97 (95%CI: 0.93; 1.03); p = 0.766) and the small for gestational age status (adjusted OR: 1.03 (95%CI: 0.99; 1.07); p = 0.351). Similar results were obtained in subgroup analyses according to COVID-19 clinical severity. CONCLUSIONS: The estimated maternal nasopharyngeal viral load in pregnant women affected by COVID-19 during the third trimester is not associated with main perinatal outcomes.


Assuntos
COVID-19 , Complicações Infecciosas na Gravidez , Recém-Nascido , Gravidez , Feminino , Humanos , SARS-CoV-2 , COVID-19/diagnóstico , Complicações Infecciosas na Gravidez/diagnóstico , Estudos de Coortes , Estudos Retrospectivos
2.
Eur J Pediatr ; 182(1): 385-392, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36374301

RESUMO

Ventilator-associated pneumonia (VAP) is a frequent nosocomial infection in neonatal intensive care units (NICU). Extremely preterm infants are at highest risk of developing VAP. Several studies indicate that oral care included in a preventive protocol effectively reduces neonatal VAP incidence. We investigated the effects of oral care with breast milk on oral immune defenses and microbiota in extremely preterm infants. Thirty infants born ≤ 30 weeks gestation hospitalized at our NICU were selected and divided into three groups: oral care with breast milk, formula, or sterile water. Effects on oral immune defenses in vivo were studied using ELISA to measure lactoferrin (LF) and secretory immunoglobulin A (sIgA) in pharyngeal aspirates before and after oral care. Different LF concentrations were tested in vitro to assess their effects on loads of selected bacterial species by culture. Effects on selected bacteria potentially responsible for VAP in vivo were studied by real-time PCR detection in pharyngeal aspirates before and after oral care. Oral care with breast milk significantly increases LF concentrations to 69.8 × 103 ng/ml (p = 0.012) and sIgA to 36.8 × 103 ng/ml (p = 0.017) in vivo. These LF concentrations considerably reduce loads of E. coli, S. epidermidis, S. aureus, and P. aeruginosa, in vitro. However, contrary to our expectation, no effect on colonization of bacteria most commonly responsible for VAP was found in vivo. CONCLUSION: In extremely preterm infants, oral care with breast milk increases local immune defense markers (LF, sIgA), which combat bacterial infections. Further clinical trials should be conducted to evaluate their effects on VAP prevention in neonates. WHAT IS KNOWN: • The population at higher risk to develop VAP are preterm infants. • Several studies indicate oral care within a preventive bundle is effective in reducing neonatal VAP incidence. WHAT IS NEW: • In extremely premature infants, oral care with breast milk causes a significant increase in local immune defences in terms of lactoferrin (LF) and secretory immunoglobulin A (sIgA). • LF concentrations obtained after oral care with breast milk decreased loads of bacteria most commonly responsible for VAP in premature infants under experimental in-vitro.


Assuntos
Lactente Extremamente Prematuro , Leite Humano , Pneumonia Associada à Ventilação Mecânica , Feminino , Humanos , Recém-Nascido , Escherichia coli , Imunoglobulina A Secretora , Unidades de Terapia Intensiva Neonatal , Lactoferrina/análise , Leite Humano/química , Pneumonia Associada à Ventilação Mecânica/prevenção & controle , Pneumonia Associada à Ventilação Mecânica/epidemiologia , Pneumonia Associada à Ventilação Mecânica/microbiologia , Staphylococcus aureus
3.
Microbiol Spectr ; 10(4): e0096422, 2022 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-35703554

RESUMO

The genus Enterobacter includes species responsible for nosocomial outbreaks in fragile patients, especially in neonatal intensive care units (NICUs). Determining the primary source of infection is critical to outbreak management and patient outcomes. In this investigation, we report the management and control measures implemented during an Enterobacter outbreak of bloodstream infections in premature babies. The study was conducted in a French NICU over a 3-year period (2016 to 2018) and included 20 premature infants with bacteremia. The clinical and microbiological characteristics were identified, and whole-genome sequencing (WGS) was performed on bacteremia isolates. Initially, several outbreak containment strategies were carried out with no success. Next, outbreak investigation pinpointed the neonatal incubators as the primary reservoir and source of contamination in this outbreak. A new sampling methodology during "on" or "in use" conditions enabled its identification, which led to their replacement, thus resulting in the containment of the outbreak. WGS analysis showed a multiclonal outbreak. Some clones were identified in different isolation sources, including patients and neonatal incubators. In addition, microbiological results showed a multispecies outbreak with a high prevalence of Enterobacter bugandensis and Enterobacter xiangfangensis. We conclude that the NICU health care environment represents an important reservoir for Enterobacter transmission and infection. Finally, extracting samples from the neonatal incubator during active use conditions improves the recovery of bacteria from contaminated equipment. This method should be used more frequently to achieve better monitoring of the NICU for HAIs prevention. IMPORTANCE Neonatal incubators in the NICU can be an important reservoir of pathogens responsible for life-threatening outbreaks in neonatal patients. Traditional disinfection with antiseptics is not sufficient to eradicate the microorganisms that can persist for long periods in the different reservoirs. Identification and elimination of the reservoirs are crucial for outbreak prevention and control. In our investigation, using a new strategy of microbiological screening of neonatal incubators, we demonstrated that these were the primary source of contamination. After their replacement, the outbreak was controlled. This new methodology was effective in containing this outbreak and could be a viable alternative for infection prevention and control in outbreak situations involving incubators as a reservoir.


Assuntos
Bacteriemia , Infecção Hospitalar , Sepse Neonatal , Bacteriemia/epidemiologia , Bacteriemia/prevenção & controle , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/microbiologia , Infecção Hospitalar/prevenção & controle , Surtos de Doenças/prevenção & controle , Enterobacter/genética , Humanos , Incubadoras , Lactente , Recém-Nascido , Sepse Neonatal/epidemiologia , Sepse Neonatal/prevenção & controle
4.
PLoS Genet ; 18(4): e1010177, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35482826

RESUMO

Class 1 integrons are widespread genetic elements playing a major role in the dissemination of antibiotic resistance. They allow bacteria to capture, express and exchange antibiotic resistance genes embedded within gene cassettes. Acquisition of gene cassettes is catalysed by the class 1 integron integrase, a site-specific recombinase playing a key role in the integron system. In in vitro planktonic culture, expression of intI1 is controlled by the SOS response, a regulatory network which mediates the repair of DNA damage caused by a wide range of bacterial stress, including antibiotics. However, in vitro experimental conditions are far from the real lifestyle of bacteria in natural environments such as the intestinal tract which is known to be a reservoir of integrons. In this study, we developed an in vivo model of intestinal colonization in gnotobiotic mice and used a recombination assay and quantitative real-time PCR, to investigate the induction of the SOS response and expression and activity of the class 1 integron integrase, IntI1. We found that the basal activity of IntI1 was higher in vivo than in vitro. In addition, we demonstrated that administration of a subinhibitory concentration of ciprofloxacin rapidly induced both the SOS response and intI1 expression that was correlated with an increase of the activity of IntI1. Our findings show that the gut is an environment in which the class 1 integron integrase is induced and active, and they highlight the potential role of integrons in the acquisition and/or expression of resistance genes in the gut, particularly during antibiotic therapy.


Assuntos
Integrases , Integrons , Intestinos , Animais , Antibacterianos/farmacologia , Bactérias/genética , Resistência Microbiana a Medicamentos , Integrases/genética , Integrases/metabolismo , Integrons/genética , Camundongos
5.
Microbiol Spectr ; 9(3): e0124221, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34937187

RESUMO

The taxonomy of the genus Enterobacter can be confusing and has been considerably revised in recent years. We propose a PCR and amplicon sequencing technique based on a partial sequence of the dnaJ gene for species assignment consistent with DNA-DNA digital hybridization (dDDH) and pairwise average nucleotide identity (ANI). We performed a validation of the method by comparing the type strains of each species, sequences obtained from the GenBank database, and clinical specimens. Our results show that the polymorphism of the target sequence of dnaJ allows the identification of species. Using this gene, we assigned the species to 100 strains deposited in the GenBank database that were consistent with the species assignment by dDDH and ANI. The analysis showed that using the partial dnaJ sequence is congruent with WGS as far as correct identification of Enterobacter species is concerned. Finally, we applied our dnaJ method on a national collection of 68 strains identified as Enterobacter isolated from the blood cultures of premature babies using an algorithm based on a type-strain library and the SeqScape software. For the first time, we identified Enterobacter quasihormaechei in blood cultures from four neonatal sepsis cases. We also noticed a higher prevalence of E. bugandensis (36.3%; 32/88) and E. xiangfangensis (46.5%; 41/88). E. bugandensis is a novel species recently described specifically in instances of neonatal sepsis. In conclusion, sequencing a part of the dnaJ gene could be a quick, more economical, and highly discriminating method of identifying Enterobacter species in clinical practice and research. IMPORTANCE We propose a new approach for Enterobacter species identification based on the diversity of the gene encoding the heat shock protein DnaJ. This new tool can be easily implemented in clinical laboratories in addition to identification by MALDI-TOF.


Assuntos
Enterobacter/classificação , Enterobacter/genética , Infecções por Enterobacteriaceae/diagnóstico , Proteínas de Choque Térmico HSP40/genética , Tipagem Molecular/métodos , Algoritmos , Sequência de Bases , DNA Bacteriano/genética , Enterobacter/isolamento & purificação , Infecções por Enterobacteriaceae/microbiologia , Genes Essenciais/genética , Humanos , Recém-Nascido , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Nucleotídeo Único/genética , RNA Ribossômico 16S/genética , Sepse/diagnóstico , Sepse/microbiologia , Análise de Sequência de DNA
6.
iScience ; 24(8): 102916, 2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34409274

RESUMO

Enterobacter cloacae complex species are involved in infections among critically ill patients. After a recent E.cloacae outbreak of fulminant neonatal septic shock, we conducted a study to determine whether septic shock severity and its lethal consequence are related to structural features of the endotoxin (lipopolysaccharide [LPS]) of the strains isolated from hospitalized infants and more specifically its lipid A region. It appeared that the LPSs are very heterogeneous, carrying fifteen different molecular species of lipid A. The virulence was correlated with a structural feature identified by matrix-assisted laser desorption ionization-time of flight mass spectrometry and gas chromatography coupled with mass spectrometry: the presence of 2-hydroxymyristic acid as a secondary substituent in lipid A. This is the first published evidence linking LPS structural moiety to neonatal sepsis outcome and opens the possibility of using this fatty acid marker as a detection tool for high-risk patients, which could help reduce their mortality.

7.
Clin Infect Dis ; 73(7): e2127-e2133, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33305785

RESUMO

BACKGROUND: Mycoplasma genitalium (MG) is an emerging pathogen among men who have sex with men (MSM) with raising rates of antibiotic resistance. This study assessed the prevalence and incidence of MG infection in MSM enrolled in the open-label phase of the ANRS IPERGAY trial with on-demand tenofovir disoproxil fumarate/emtricitabine for human immunodeficiency virus prevention and the impact of doxycycline post-exposure prophylaxis (PEP). METHODS: 210 subjects were tested at baseline and at 6 months by real-time PCR assays for MG detection in urine samples and oropharyngeal and anal swabs. Resistance to azithromycin (AZM), to fluoroquinolones (FQs), and to doxycycline was investigated in the French National Reference Center of Bacterial Sexually Transmitted Infections (STIs). RESULTS: The all-site prevalence of MG at baseline was 10.5% (6.3% in urine samples, 4.3% in anal swabs, 0.5% in throat swabs) and remained unchanged at 6 months whether or not PEP was used: 9.9% overall, 10.2% with PEP, 9.6% without. The overall rate of MG resistance (prevalent and incident cases) to AZM and FQs was 67.6% and 9.1%, respectively, with no difference between arms. An in vivo mutation of the MG 16S rRNA, which could be associated with tetracycline resistance, was observed in 12.5% of specimens tested. CONCLUSIONS: The prevalence of MG infection among MSM on pre-exposure prophylaxis was high and its incidence was not decreased by doxycycline prophylaxis with a similar high rate of AZM and FQ resistance, raising challenging issues for the treatment of this STI and supporting current recommendations to avoid testing or treatment of asymptomatic MG infection.


Assuntos
Infecções por HIV , Infecções por Mycoplasma , Mycoplasma genitalium , Profilaxia Pré-Exposição , Minorias Sexuais e de Gênero , Resistência Microbiana a Medicamentos , Infecções por HIV/epidemiologia , Homossexualidade Masculina , Humanos , Masculino , Infecções por Mycoplasma/tratamento farmacológico , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/prevenção & controle , Mycoplasma genitalium/genética , Prevalência , RNA Ribossômico 16S
8.
PLoS One ; 15(10): e0240782, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33057392

RESUMO

BACKGROUND: To fight the COVID-19 pandemic, lockdown has been decreed in many countries worldwide. The impact of pregnancy as a severity risk factor is still debated, but strict lockdown measures have been recommended for pregnant women. OBJECTIVES: To evaluate the impact of the COVID-19 pandemic and lockdown on the seroprevalence and circulation of SARS-CoV-2 in a maternity ward in an area that has been significantly affected by the virus. STUDY DESIGN: Prospective study at the Antoine Béclère Hospital maternity ward (Paris area, France) from May 4 (one week before the end of lockdown) to May 31, 2020 (three weeks after the end of lockdown). All patients admitted to the delivery room during this period were offered a SARS-CoV-2 serology test as well concomitant SARS-CoV-2 RT-PCR on one nasopharyngeal sample. RESULTS: A total of 249 women were included. Seroprevalence of SARS-CoV-2 was 8%. The RT-PCR positive rate was 0.5%. 47.4% of the SARS-CoV-2-IgG-positive pregnant women never experienced any symptoms. A history of symptoms during the epidemic, such as fever (15.8%), myalgia (36.8%) and anosmia (31.6%), was suggestive of previous infection. CONCLUSIONS: Three weeks after the end of French lockdown, SARS-CoV-2 infections were scarce in our region. A very high proportion of SARS-CoV-2-IgG-negative pregnant women, which is comparable to that of the general population, must be taken into consideration in the event of a resurgence of the pandemic. The traces of a past active circulation of the virus in this fragile population during the spring wave should encourage public health authorities to take specific measures for this independent at-risk group, in order to reduce viral circulation in pregnant patients.


Assuntos
Betacoronavirus/genética , Betacoronavirus/imunologia , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Parto , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Adulto , Anticorpos Antivirais/sangue , COVID-19 , Teste para COVID-19 , Vacinas contra COVID-19 , Infecções por Coronavirus/microbiologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/virologia , Feminino , Humanos , Imunoglobulina G/sangue , Pandemias/prevenção & controle , Paris/epidemiologia , Pneumonia Viral/prevenção & controle , Pneumonia Viral/virologia , Gravidez , Complicações Infecciosas na Gravidez/virologia , Estudos Prospectivos , Quarentena/métodos , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , SARS-CoV-2 , Estudos Soroepidemiológicos , Testes Sorológicos
9.
Eur J Clin Microbiol Infect Dis ; 39(11): 2185-2194, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32519215

RESUMO

To increase the knowledge about S. capitis in the neonatal setting, we conducted a nationwide 3-month survey in 38 neonatal intensive care units (NICUs) covering 56.6% of French NICU beds. We demonstrated 14.2% of S. capitis BSI (S.capBSI) among nosocomial BSIs. S.capBSI incidence rate was 0.59 per 1000 patient-days. A total of 55.0% of the S.capBSIs were late onset catheter-related BSIs. The S. capitis strains infected preterm babies (median gestational age 26 weeks, median birth weight 855 g). They were resistant to methicillin and aminoglycosides and belonged to the NRCS-A clone. Evolution was favorable in all but one case, following vancomycin treatment.


Assuntos
Sepse/epidemiologia , Infecções Estafilocócicas/epidemiologia , Staphylococcus capitis/isolamento & purificação , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções Relacionadas a Cateter/tratamento farmacológico , Infecções Relacionadas a Cateter/epidemiologia , Infecções Relacionadas a Cateter/etiologia , Farmacorresistência Bacteriana Múltipla , Feminino , França/epidemiologia , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Masculino , Sepse/tratamento farmacológico , Sepse/etiologia , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/etiologia , Staphylococcus capitis/efeitos dos fármacos
11.
Artigo em Inglês | MEDLINE | ID: mdl-30275089

RESUMO

Methicillin-resistant Staphylococcus aureus (MRSA) infection has increased in recent years among cystic fibrosis (CF) patients. Linezolid (LZD) is one of the antistaphylococcal antibiotics widely used in this context. Although LZD resistance is rare, it has been described as often associated with long-term treatments. Thirteen MRSA strains isolated over 5 years from one CF patient were studied for LZD resistance emergence and subjected to whole-genome sequencing (WGS). Resistance emerged after three 15-day LZD therapeutic regimens over 4 months. It was associated with the mutation of G to T at position 2576 (G2576T) in all 5 rrl copies, along with a very high MIC (>256 mg/liter) and a strong increase in the generation time. Resistant strains isolated during the ensuing LZD therapeutic regimens and until 13 months after LZD stopped harbored only 3 or 4 mutated rrl copies, associated with lower MICs (8 to 32 mg/liter) and low to moderate generation time increases. Despite these differences, whole-genome sequencing allowed us to determine that all isolates, including the susceptible one isolated before LZD treatment, belonged to the same lineage. In conclusion, LZD resistance can emerge rapidly in CF patients and persist without linezolid selective pressure in colonizing MRSA strains belonging to the same lineage.


Assuntos
Fibrose Cística/microbiologia , Interações Hospedeiro-Patógeno/genética , Linezolida/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Farmacorresistência Bacteriana/efeitos dos fármacos , Farmacorresistência Bacteriana/genética , Evolução Molecular , Genoma Bacteriano , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Filogenia , Polimorfismo de Nucleotídeo Único , Infecções Estafilocócicas/tratamento farmacológico , Fatores de Tempo
13.
J Pediatr ; 200: 30-37.e2, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29793870

RESUMO

OBJECTIVES: To establish the reference values, diagnostic accuracy, and effect of various factors on cell count in intubated preterm neonates subjected to nonbronchoscopic bronchoalveolar lavage. STUDY DESIGN: This prospective, cross-sectional, blinded study included preterm neonates ventilated for any reason who underwent nonbronchoscopic bronchoalveolar lavage if they had not previously received postnatal antibiotics or steroids. Lavage was performed before surfactant replacement, if any. A gentle ventilation policy was applied. Pneumonia was diagnosed using clinical criteria, without considering cell count. Investigators performing cell counts were blinded to the clinical data. RESULTS: There were 276 neonates enrolled; 36 had congenital or ventilator-associated pneumonia. In the 240 noninfected babies, median neutrophil count increased significantly after the first 2 days of ventilation (day 1, 2 cells per field [IQR, 0.0-9.5 cells per field]; day 2, 2 cells per field [IQR, 0-15 cells per field]; day 3, 20 cells per field [IQR, 2-99 cells per field]; day 4, 15 cells per field [IQR, 2-96 cells per field]; P < .0001). No significant difference was seen over time in infected babies. Multivariate analysis indicated pneumonia (standardized ß = 0.134; P = .033) and the time spent under mechanical ventilation before nonbronchoscopic bronchoalveolar lavage as factors significantly influencing neutrophil count (standardized ß = 0.143; P = .027). Neutrophil count was correlated with the duration of ventilation (rho = 0.28; P <.001). Neutrophil counts were higher in infected (24 cells/field [IQR, 5-78] cells/field) than in noninfected babies (4 cells/field [IQR, 1-24 cells/field]; P <.001) and had an moderate reliability for pneumonia within the first 2 days of ventilation (area under the curve, 0.745; (95% CI, 0.672-0.810; P = .002). CONCLUSIONS: We provide reference values for airway neutrophil counts in ventilated preterm neonates. Bronchoalveolar lavage neutrophils significantly increase after 2 days of ventilation. Neutrophil count has moderate accuracy to diagnose pneumonia, but only within the first 2 days of ventilation.


Assuntos
Líquido da Lavagem Broncoalveolar/citologia , Lavagem Broncoalveolar/métodos , Recém-Nascido Prematuro , Pneumonia Associada à Ventilação Mecânica/diagnóstico , Respiração Artificial/efeitos adversos , Broncoscopia , Contagem de Células , Estudos Transversais , Feminino , Seguimentos , Humanos , Recém-Nascido , Masculino , Estudos Prospectivos , Reprodutibilidade dos Testes
14.
Microb Drug Resist ; 23(4): 462-467, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27754824

RESUMO

Linezolid (LZD) has arisen as an alternative treatment in diabetic foot osteitis due to staphylococci. LZD resistance selection is difficult and involved various molecular mechanisms. As a better knowledge of those mechanisms could be beneficial for pathogenic strains' screening, we simulated in vitro the spontaneous mutagenesis process that leads to LZD-resistant strains from two Staphylococcus epidermidis strains responsible for monomicrobial diabetic foot osteitis. LZD high resistance was selected for both strains, with the same timeline of mutation appearance. Mutation in L3 protein (G152D) occurred first and quickly, but did not cause phenotypically detectable resistance or fitness cost. It was later followed by different 23S rRNA mutations (G2505A, G2447T), leading this time to detectable resistance (minimum inhibitory concentration [MIC] ≥8 mg/L). This phenomenon underlies the difficulty of resistance selection in coagulase-negative staphylococci (CoNS). This study is the first description of G2505A mutation in CoNS. Various phenotypical impacts were observed depending on strain and mutation: (i) fitness cost of G2505A and G2447T mutations; (ii) loss of erythromycin resistance concomitantly with L3 mutation selection; (iii) correlation between number of mutated rrl copies and LZD resistance level for G2447T. In conclusion, the risk of selection of high-level LZD-resistant S. epidermidis strains is weak, but does exist. It could probably appear in case of long-term treatment and be favored in the case of a pre-existing mutation in L3 ribosomal protein. Thus, broad screening conditions for pathogenic strains should probably be considered.


Assuntos
DNA Ribossômico/genética , Farmacorresistência Bacteriana/genética , Linezolida/farmacologia , RNA Ribossômico 23S/genética , Proteínas Ribossômicas/genética , Staphylococcus epidermidis/genética , Antibacterianos/farmacologia , Pé Diabético/microbiologia , Aptidão Genética , Humanos , Testes de Sensibilidade Microbiana , Osteíte/microbiologia , Fenótipo , Mutação Puntual , Biossíntese de Proteínas/efeitos dos fármacos , Proteína Ribossômica L3 , Ribossomos/efeitos dos fármacos , Ribossomos/genética , Risco , Seleção Genética , Infecções Estafilocócicas/microbiologia , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/metabolismo
16.
Int J Antimicrob Agents ; 46(6): 622-30, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26453147

RESUMO

Multiresistance in staphylococci constitutes a major challenge for the antimicrobial chemotherapy of invasive infections such as bacteraemia or bone and joint infections (BJIs). A nationwide prospective study was performed to detect antimicrobial resistance trends among staphylococci causing invasive infections. Between October 2011 and February 2012, 367 meticillin-resistant Staphylococcus aureus (MRSA) and 695 coagulase-negative staphylococci (CoNS) were collected from 37 French hospitals, mainly from bacteraemia (59.9%) and osteoarticular infections (29.0%). Minimum inhibitory concentrations (MICs) were determined by broth microdilution, and specific screening and confirmation tests were performed to detect heterogeneous vancomycin-intermediate S. aureus (hVISA). Staphylococcal isolates exhibiting a linezolid MIC>4 mg/L were further characterised to determinate their clonal relationships and the mechanism of resistance. MRSA exhibited additional resistances, including levofloxacin (82% associated resistance), gentamicin (13.6%), fusidic acid (13.6%) and rifampicin (6.5%), compromising oral step-down therapy in BJIs. Only two hVISA strains (0.5%) were identified. Among the CoNS, mainly Staphylococcus epidermidis (506/695; 72.8%), resistance to first- and second-line agents was more common. Linezolid resistance was identified in 10 CoNS (1.4%). The most frequent linezolid resistance mechanism was the G2576T mutation in 23S rDNA (9/10). For the first time in France, the cfr gene was found in five related sequence type 2 (ST2) S. epidermidis from two different hospitals, in association with ribosomal RNA and L3 ribosomal protein mutations. These national data must be considered when selecting empirical treatment for invasive staphylococcal infections. Moreover, the emergence and spread of linezolid-resistant CoNS carrying the cfr gene is of concern.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Linezolida/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Proteínas de Bactérias/genética , Coagulase/genética , França , Ácido Fusídico/farmacologia , Gentamicinas/farmacologia , Hospitais , Humanos , Levofloxacino/farmacologia , Meticilina/farmacologia , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Testes de Sensibilidade Microbiana , Estudos Prospectivos , RNA Ribossômico 23S/genética , Rifampina/farmacologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Infecções Estafilocócicas/microbiologia , Staphylococcus epidermidis/isolamento & purificação
17.
Folia Microbiol (Praha) ; 59(6): 473-6, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24859920

RESUMO

For the first time, it was reported in France a cluster of autochthonous severe community-acquired (CA) infections due to the USA300 methicillin-resistant Staphylococcus aureus (MRSA) clone. The three cases belonged to the same family without any identified clue of abroad importation pathway. The domestic spread of USA300 in France is of concern.


Assuntos
Infecções Comunitárias Adquiridas/microbiologia , Leucocidinas/metabolismo , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Staphylococcus aureus Resistente à Meticilina/metabolismo , Infecções Estafilocócicas/microbiologia , Adulto , Pré-Escolar , Feminino , França , Humanos , Lactente , Masculino , Resistência a Meticilina , Staphylococcus aureus Resistente à Meticilina/genética
18.
Am J Infect Control ; 41(10): 918-21, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23769834

RESUMO

BACKGROUND: Bacillus cereus is an environmental pathogen whose spores resist the usual cleaning procedure applied by the food industry and hospitals. We reported a cluster of severe intestinal infections due to B cereus in 2 very low birth weight neonates from a neonatal intensive care unit. METHODS: Environmental sampling and bacteriological analysis of pooled breast milk (PBM) were performed. Practices for preparation and administration of milk were observed and additional laboratory experiments performed. Strains were typed using M13-polymerase chain reaction and their virulence tested using cellular and insect models. RESULTS: B cereus strains were exclusively isolated from intestinal tracts and PBM. No environmental culture yielded any viable B cereus. Although genotypically diverse, both clinical and food strains exhibited high virulence potency. These findings pointed out the pathogenic potency of B cereus in neonates; the putative role of PBM as a reservoir for pathogenic B cereus and the triggered effect of a defective care procedure, which allowed the growth of bacteria in pasteurized PBM. Well described from dried formula, the presence of pathogenic B cereus strains in PBM was not previously reported. CONCLUSIONS: Careful monitoring of conditions during collection, conservation, and administration of PBM should be implemented in high-risk populations such as premature neonates.


Assuntos
Bacillus cereus/isolamento & purificação , Infecção Hospitalar/diagnóstico , Doenças Transmitidas por Alimentos/diagnóstico , Infecções por Bactérias Gram-Positivas/diagnóstico , Recém-Nascido Prematuro , Leite Humano/microbiologia , Bacillus cereus/classificação , Bacillus cereus/genética , Infecção Hospitalar/microbiologia , DNA Bacteriano/genética , Microbiologia Ambiental , Doenças Transmitidas por Alimentos/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Recém-Nascido , Reação em Cadeia da Polimerase , Fatores de Virulência/genética
19.
J Clin Microbiol ; 51(4): 1305-6, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23390279

RESUMO

The Xpert GBS real-time PCR assay for the detection of group B streptococci (GBS) in antepartum screening samples was evaluated on amniotic fluid samples collected from 139 women with premature rupture of membrane at term. When any intrapartum positive result from the Xpert GBS or culture was considered a true positive, the sensitivities of the Xpert GBS and culture were 92.3% and 84.6%, respectively. This assay could enhance exact identification of candidates for intrapartum antibiotic prophylaxis.


Assuntos
Técnicas Bacteriológicas/métodos , Ruptura Prematura de Membranas Fetais , Técnicas de Diagnóstico Molecular/métodos , Complicações Infecciosas na Gravidez/diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Infecções Estreptocócicas/diagnóstico , Streptococcus agalactiae/isolamento & purificação , Feminino , Humanos , Gravidez , Estudos Prospectivos , Streptococcus agalactiae/genética , Streptococcus agalactiae/crescimento & desenvolvimento
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