RESUMO
High-level delafloxacin-resistant (H-L DLX-R) Staphylococcus aureus isolates (minimum inhibitory concentration ≥1 mg/L) associated with mutations affecting position 84 of ParC have emerged. We aimed to elucidate the role of these mutations as a mechanism of H-L DLX resistance in methicillin-resistant S. aureus (MRSA) isolates recovered from blood cultures. Susceptibility to DLX was determined in 75 MRSA isolates by E-test, and an rt-PCR was developed to detect mutations affecting position 84 of ParC to screen a further 185 MRSA isolates. The genomes of 48 isolates, including all DLX-R isolates or with alterations at position 84, and also a subset of DLX-susceptible isolates were analyzed. Among the 75 isolates studied, 77.34% were DLX-susceptible and only 4 H-L DLX-R isolates were found. Seven (3.8%) isolates with alterations at position 84 of ParC were detected by rt-PCR. Genomic analysis showed that 89.9% (8/9) of isolates with the substitution E84K/G in ParC, together with other mutations in gyrA and parC, were H-L DLX-R. However, the E84K substitution in ParC alone or with other alterations was found in two isolates without H-L DLX-R. Alterations at position 84 of ParC are rare but play a key role in H-L DLX resistance in MRSA but only when other alterations in GyrA are present.
RESUMO
OBJECTIVES: The aims of this study were: (i) to assess the ability of the meropenem screening breakpoint as part of the screening rapid antimicrobial susceptibility testing (sRAST) of EUCAST for the detection of OXA-48 carbapenemase-producing Klebsiella pneumoniae directly from positive blood cultures (BCs); and (ii) to evaluate the inclusion of ertapenem and temocillin discs into the sRAST to enhance the detection of OXA-48-producing isolates. METHODS: BC bottles were spiked with a total of 117 K. pneumoniae isolates, including 77 previously characterized OXA-48 producers and 40 non-OXA-48 producers. Disc diffusion assays were directly performed from positive BCs with meropenem (10 µg), ertapenem (10 µg) and temocillin (30 µg) discs, and inhibition zones were manually measured after 4, 6 and 8 h of incubation. The screening cut-off values of sRAST were applied to evaluate their capability in detecting OXA-48-producing isolates. Receiver operating characteristic curves were constructed to illustrate the performance efficacy of the disc diffusion assays to detect OXA-48 producers. RESULTS: The meropenem cut-off values of sRAST only detected 90.91% of the OXA-48-producing isolates after 6 and 8 h of incubation. With the proposed cut-off points for ertapenem [<19 mm (4/6 h) and <20 mm (8 h)] and temocillin [<10 mm (4 h) and <11 mm (6/8 h)], all OXA-48-positive isolates were detected without any false-positive results at any reading time. CONCLUSIONS: In healthcare settings with a high prevalence of OXA-48 producers, the inclusion of ertapenem and temocillin discs in the sRAST procedure may improve the detection of OXA-48-producing K. pneumoniae isolates directly from positive BCs, providing reliable results after only a 4 h incubation period.
Assuntos
Anti-Infecciosos , Klebsiella pneumoniae , Penicilinas , Ertapenem , Meropeném/farmacologia , Proteínas de Bactérias , beta-Lactamases , Hemocultura , Antibacterianos/farmacologia , Testes de Sensibilidade MicrobianaRESUMO
Enterococcus is a diverse genus of Gram-positive bacteria belonging to the lactic acid bacteria (LAB) group. It is found in many environments, including the human gut and fermented foods. This microbial genus is at a crossroad between its beneficial effects and the concerns regarding its safety. It plays an important role in the production of fermented foods, and some strains have even been proposed as probiotics. However, they have been identified as responsible for the accumulation of toxic compounds-biogenic amines-in foods, and over the last 20 years, they have emerged as important hospital-acquired pathogens through the acquisition of antimicrobial resistance (AMR). In food, there is a need for targeted measures to prevent their growth without disturbing other LAB members that participate in the fermentation process. Furthermore, the increase in AMR has resulted in the need for the development of new therapeutic options to treat AMR enterococcal infections. Bacteriophages have re-emerged in recent years as a precision tool for the control of bacterial populations, including the treatment of AMR microorganism infections, being a promising weapon as new antimicrobials. In this review, we focus on the problems caused by Enterococcus faecium and Enterococcus faecalis in food and health and on the recent advances in the discovery and applications of enterococcus-infecting bacteriophages against these bacteria, with special attention paid to applications against AMR enterococci.
RESUMO
The rise of antimicrobial resistant (AMR) bacteria is a major health concern, especially with regard to members of the ESKAPE group, to which vancomycin-resistant (VRE) Enterococcus faecium belongs. Phage therapy has emerged as a novel alternative for the treatment of AMR infections. This, however, relies on the isolation and characterisation of a large collection of phages. This work describes the exploration of human faeces as a source of new E. faecium-infecting phages. Phage vB_EfaH_163 was isolated and characterised at the microbiological, genomic, and functional levels. vB_EfaH_163 phage, a new member of Herelleviridae, subfamily Brockvirinae, has a dsDNA genome of 150,836 bp that does not harbour any virulence factors or antibiotic resistance genes. It infects a wide range of E. faecium strains of different origins, including VRE strains. Interestingly, it can also infect Enterococcus faecalis strains, even some that are linezolid-resistant. Its capacity to control the growth of a clinical VRE isolate was shown in broth culture and in a Galleria mellonella animal model. The discovery and characterisation of vB_EfaH_163 increases the number of phages that might be used therapeutically against AMR bacteria.
Assuntos
Bacteriófagos , Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Mariposas , Enterococos Resistentes à Vancomicina , Humanos , Animais , Enterococcus faecium/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Linezolida/uso terapêutico , Mariposas/microbiologia , Modelos Animais , Infecções por Bactérias Gram-Positivas/microbiologia , Testes de Sensibilidade MicrobianaRESUMO
Dispersion of transferable oxazolidinone resistance genes among enterococci poses a serious problem to human health. Prompt detection of bacteria carrying these genes is crucial to avoid their spread to multidrug-resistant bacteria. The aim of the study was to describe the presence of optrA-positive isolates among enterococci in a Spanish hospital, and to determine their genetic context and location through whole genome sequencing. All enterococci recovered in a Spanish hospital (Hospital El Bierzo; HEB) from February to December 2018 (n = 443), with minimal inhibitory concentrations (MICs) to linezolid (LZD) ≥4 mg/L, were tested by polymerase chain reaction for the presence of cfr, optrA, and poxtA transferable genes. Only four Enterococcus faecalis isolates (0.9%) had LZD MICs ≥4 mg/L and none of them was positive for cfr or poxtA genes. However, the optrA gene was detected in three isolates collected from urine samples of community patients, whose genomes were sequenced and subjected to bioinformatics analysis. These isolates belonged to different clones: ST7, ST480, and ST585. In these three isolates, the optrA gene was located on plasmids, associated with IS1216 in different arrays. In one isolate, the optrA plasmid coexists with a second plasmid, which carried multiple resistance genes for different classes of antibiotics. Detection of optrA-positive E. faecalis isolates in the community is a matter of concern. The spread of these bacteria into hospital settings, particularly in those, such as the HEB, where vancomycin-resistant enterococci are endemic, should be avoided, to preserve the efficacy of the last-resort oxazolidinones.
Assuntos
Enterococcus faecium , Infecções por Bactérias Gram-Positivas , Oxazolidinonas , Antibacterianos/farmacologia , Fatores de Transcrição Hélice-Alça-Hélice Básicos , Farmacorresistência Bacteriana/genética , Enterococcus , Enterococcus faecalis , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Infecções por Bactérias Gram-Positivas/epidemiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Linezolida/farmacologia , Testes de Sensibilidade Microbiana , Oxazolidinonas/farmacologiaRESUMO
Vancomycin-resistant Enterococcus faecium (VREfm) is one of the most important nosocomial pathogens with limited therapeutic alternatives. In this study, we followed the trends of VREfm and E. faecium causing bloodstream infections (BSIs) in a Spanish hospital, from 2011 to 2020. During this period, 832 E. faecium strains were isolated and 121 (14.5%) were vancomycin resistant. Nineteen of 101 BSIs (18.8%) caused by E. faecium were due to VREfm. The number of BSI-producing E. faecium isolates increased significantly over the past 5 years, with the percentage of invasive VREfm isolates being substantially higher than the average values in Europe and especially in Spain (<3%). VREfm isolates recovered in 2018 (28) and BSI-producing isolates from 2019 (3) and 2020 (2) were molecularly characterized. All were positive for vanA and belonged to sequence type (ST) 80 (28) or ST117 (5), within clonal complex 17. The isolates were only susceptible to linezolid, although most of them were also susceptible (dose dependent) to daptomycin. We report for the first time the establishment and persistence of the VREfm ST80 and ST117 clones in a Spanish hospital. The spread and establishment of hospital-adapted, multidrug-resistant VREfm clones in health care settings are cause for concern and may precede an increment in the BSIs caused by them.
Assuntos
Antibacterianos/farmacologia , Bacteriemia/microbiologia , Enterococcus faecium/efeitos dos fármacos , Glicopeptídeos/farmacologia , Infecções por Bactérias Gram-Positivas/microbiologia , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Células Clonais , Infecção Hospitalar/microbiologia , Instalações de Saúde , Humanos , Testes de Sensibilidade MicrobianaRESUMO
The aim of the study was to evaluate for a long time the effectiveness of an intervention designed to reduce carbapenem-resistant Acinetobacter baumannii (CRAB) and its impact on colistin usage in the ICU of a tertiary hospital in Spain. The rate of carbapenem resistance declined drastically during the period of study (2015 to 2018), from 93.57 to 74.65%, especially in the ICU. A significant decrease in colistin usage, from 1.16 to 0.39 DOTs, was observed. Forty-nine CRAB isolates recovered nearly 1 year after starting the intervention were characterized. Most of them were recovered from patients admitted in wards other than ICU and were extensively drug-resistant, carried blaOXA-23-like and armA, and belonged to ST218. Implementation of control measures is crucial to CRAB control in ICUs but must be extended to all wards in order to eradicate CRAB from hospitals.
Assuntos
Infecções por Acinetobacter/prevenção & controle , Infecção Hospitalar/prevenção & controle , Desinfecção/métodos , Doenças Endêmicas/prevenção & controle , Unidades de Terapia Intensiva/organização & administração , Infecções por Acinetobacter/epidemiologia , Acinetobacter baumannii/efeitos dos fármacos , Acinetobacter baumannii/isolamento & purificação , Carbapenêmicos , Infecção Hospitalar/epidemiologia , Farmacorresistência Bacteriana Múltipla , Humanos , Espanha/epidemiologia , Centros de Atenção TerciáriaRESUMO
BACKGROUND: Linezolid has good penetration to the meninges and could be an alternative for treatment of Staphylococcus aureus meningitis. We assessed the efficacy and safety of linezolid therapy for this infection. METHODS: Retrospective multicenter cohort study of 26 adults treated with linezolid, derived from a cohort of 350 cases of S. aureus meningitis diagnosed at 11 university hospitals in Spain (1981-2015). RESULTS: There were 15 males (58%) and mean age was 47.3 years. Meningitis was postoperative in 21 (81%) patients. The infection was nosocomial in 23 (88%) cases, and caused by methicillin-resistant S. aureus in 15 cases and methicillin-susceptible S. aureus in 11. Linezolid was given as empirical therapy in 10 cases, as directed therapy in 10, and due to failure of vancomycin in 6. Monotherapy was given to 16 (62%) patients. Median duration of linezolid therapy was 17 days (IQR 12-22 days) with a daily dose of 1,200 mg in all cases. The clinical response rate to linezolid was 69% (18/26) and microbiological response was observed in 14 of 15 cases evaluated (93%). Overall 30-day mortality was 23% and was directly associated with infection in most cases. When compared with the patients of the cohort, no significant difference in mortality was observed between patients receiving linezolid or vancomycin for therapy of methicillin-resistant S. aureus meningitis (9% vs. 20%; p = .16) nor between patients receiving linezolid or cloxacillin for therapy of methicillin-susceptible S. aureus meningitis (20% vs 14%; p = .68). Adverse events appeared in 14% (3/22) of patients, but linezolid was discontinued in only one patient. CONCLUSIONS: Linezolid appears to be effective and safe for therapy of S. aureus meningitis. Our findings showed that linezolid may be considered an adequate alternative to other antimicrobials in meningitis caused by S. aureus.
Assuntos
Infecção Hospitalar , Linezolida/uso terapêutico , Meningites Bacterianas/tratamento farmacológico , Infecções Estafilocócicas , Adulto , Antibacterianos/uso terapêutico , Infecção Hospitalar/tratamento farmacológico , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina , Pessoa de Meia-Idade , Estudos Retrospectivos , Espanha , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureusRESUMO
BACKGROUND: Pseudomonas aeruginosa neurosurgical meningitis is a rare entity, usually related with intraventricular catheters and associated with high mortality rates. We describe the clinical characteristics, treatment and outcomes of a series of neurosurgical meningitis caused by P. aeruginosa along 1990-2016. METHODS: Descriptive, retrospective study of all postsurgical meningitis due to P. aeruginosa related to intraventricular catheters in Hospital Universitario Central de Asturias, between 1990 and 2016. Clinical features, therapeutic approaches and prognostic factors were analyzed statistically. A binary logistic regression analysis was performed to determine the factors influencing the infection mortality. RESULT: 51 episodes from 51 different patients with CSF culture positive for P. aeruginosa were reviewed. Seventeen patients (33.3%) died as a direct consequence of the infection. Univariate analysis showed that mortality was higher in the group of patients treated with ceftazidime (12 vs. 15, p=0.068, OR 3.040 [0.877-10.544]) and lower in patients whom had received intrathecal therapy (2 vs. 13, p=0.050, OR 4.64 [0.80-34.93]), without differences observed between those patients treated with aminoglycosides or with colistin. Any patient treated with colistin died (0 vs. 6, p=0.067, OR: not defined). In the multivariate analysis mortality was only significant higher for patients without catheter withdrawal (p=0.014) and lower for those patients who received intrathecal therapy (p=0.05) or adequate empirical treatment (p=0.006). CONCLUSIONS: The mortality of P. aeruginosa meningitis is high especially in infections without catheter withdrawal and in patients for whom the intrathecal route of administration was not used. Catheter withdrawal was an independent factor of good outcome in our series.
Assuntos
Antibacterianos/uso terapêutico , Cateteres Cardíacos/microbiologia , Infecção Hospitalar , Meningites Bacterianas/tratamento farmacológico , Infecções por Pseudomonas/tratamento farmacológico , Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/mortalidade , Hospitais , Humanos , Meningites Bacterianas/mortalidade , Procedimentos Neurocirúrgicos , Infecções por Pseudomonas/mortalidade , Pseudomonas aeruginosa , Estudos RetrospectivosRESUMO
We report a case of urinary tract infection caused by an unusual genotype (sequence type 211) of Pasteurella multocida associated with human infection. Molecular genetic analysis of P. multocida isolates obtained from the human patient and his pet strongly suggests a zoonotic transmission of this bacterium.
Assuntos
Infecções por Pasteurella/microbiologia , Infecções por Pasteurella/transmissão , Pasteurella multocida , Zoonoses/microbiologia , Zoonoses/transmissão , Idoso de 80 Anos ou mais , Animais , Doenças do Cão/microbiologia , Cães , Humanos , Masculino , Infecções por Pasteurella/diagnóstico , Infecções por Pasteurella/epidemiologia , Pasteurella multocida/classificação , Pasteurella multocida/genética , Espanha/epidemiologia , Infecções Urinárias/diagnóstico , Infecções Urinárias/microbiologia , Infecções Urinárias/transmissãoRESUMO
Blood stream infections are serious conditions associated with high morbi-mortality. In this study, the new Sepsis Flow Chip (SFC) assay for identification of Gram-negative bacteria and their antimicrobial resistance genes was evaluated in positive blood cultures (BCs). SFC is a microarray with a broad panel comprising the most frequent causative agents of sepsis and antimicrobial resistance genes associated with them. A total of 100 prospective BCs, positive for Gram-negative bacilli, were assessed in the routine of the clinical microbiology laboratory and also applying the SFC assay. Moreover, 19 BCs spiked with well-characterized enterobacterial isolates, harboring antimicrobial resistance genes, were analyzed by the latter. Among the monomicrobial BCs (90), the concordance between SFC identification and the reference method was 94.4%; however, it achieved 100% when SFC was combined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry after 4-h incubation. Regarding polymicrobial BCs (10), 15 out of the 22 bacteria present (68.2%) were correctly identified, including all contained in 50% of the cultures. With regard to antimicrobial resistance genes, 98.8%, 98.9%, and 99% concordance was obtained for blaCTX-M, blaOXA-48, and blaVIM, respectively, in comparison with polymerase chain reaction amplification. SFC assay gives results in only 4 h and showed a high concordance rate with the reference method. Although further evaluation studies are necessary, SFC assay implementation, together with antimicrobial stewardship programs, could contribute to improve the therapeutic approaches and to reduce the morbi-mortality, length of hospital stay, and healthcare-associated costs in patients with sepsis.
Assuntos
Infecções por Bactérias Gram-Negativas/diagnóstico , Análise em Microsséries/métodos , Testes de Sensibilidade Microbiana/métodos , Técnicas de Diagnóstico Molecular/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Sepse/diagnóstico , Hemocultura/métodos , Humanos , Estudos Prospectivos , Fatores de TempoRESUMO
A new protocol for Enterobacteriaceae identification and detection of carbapenemase-producing isolates from blood cultures by combining MALDI-TOF MS and the Carba NP test has been evaluated. Bacterial identification was correct in 129 of the 130 isolates tested while the Carba NP detected 28 out of the 29 carbapenemase producers.