Imipenem-resistant Pseudomonas aeruginosa resulting from metallo-β-lactamases has been reported to be an important cause of nosocomial infection and is a critical therapeutic problem worldwide, ...especially in the case of bacteremia.
To determine the frequency of metallo-β-lactamases among imipenem-resistant Pseudomonas aeruginosa isolates and to compare methods of phenotypic and molecular detection.
During 2006, 69 imipenem-resistant Pseudomonas aeruginosa samples were isolated from blood and tested for metallo-β-lactamase production using phenotypic methods. Minimal Inhibitory Concentratrions (MIC) (µg/mL) was determined with commercial microdilution panels. Pulsed Field Gel Electrophoresis (PFGE) was performed among metallo-β-lactamase producers.
Of all the blood isolates, 34.5% were found to be imipenem-resistant Pseudomonas aeruginosa. Positive phenotypic tests for metallo-β-lactamases ranged from 28%-77%, and Polymerase Chain Reaction (PCR) were positive in 30% (of note, 81% of those samples were blaSPM-1 and 19% were blaVIM-2). Ethylenediamine tetracetic acid (EDTA) combinations for the detected enzymes had low kappa values; thus, care should be taken when use it as a phenotypic indicator of MBL. Despite a very resistant antibiogram, four isolates demonstrated the worrisome finding of a colistin MIC in the resistant range. PFGE showed a clonal pattern.
Metallo-β-lactamases among imipenem-resistant Pseudomonas aeruginosa were detected in 30.4% of imipenem-resistant Pseudomonas aeruginosa isolates. This number might have been higher if other genes were included. SPM-1 was the predominant enzyme found. Phenotypic tests with low kappa values could be misleading when testing for metallo-β-lactamases. Polymerase Chain Reaction detection remains the gold standard.
Polymyxins are one of most important antibiotics available for multidrug-resistant Gram-negative infections. Diverse chromosomal resistance mechanisms have been described, but the polymyxin ...resistance phenotype is not yet completely understood. The objective of this study was to characterize colistin resistant
mcr-1
-producing strains isolated from human infections over one year in a hospital setting (Hospital das Clínicas, São Paulo, Brazil). We isolated 490 colistin-resistant Gram-negative rods, of which eight were
mcr-1.1
-positive
Escherichia coli
, the only species with this result, indicating a low incidence of the
mcr-1
production mechanism among colistin-resistant isolates. All
mcr-1.1
positive isolates showed similarly low MICs for colistin and were susceptible to most antibiotics tested. The isolates showed diversity of MLST classification. The eight
mcr-1.1
-positive
E. coli
genomes were sequenced. In seven of eight isolates the
mcr-1.1
gene is located in a contig that is presumed to be a part of an IncX4 plasmid; in one isolate, it is located in a contig that is presumed to be part of an IncHI2A plasmid. Three different genomic contexts for
mcr-1.1
were observed, including a genomic cassette
mcr-1.1-pap2
disrupting a DUF2806 domain-containing gene in six isolates. In addition, an IS1-family transposase was found inserted next to the
mcr-1.1
cassette in one isolate. An
mcr-1.1-pap2
genomic cassette not disrupting any gene was identified in another isolate. Our results suggest that plasmid dissemination of hospital-resident strains took place during the study period and highlight the need for continued genomic surveillance.
Colistin susceptibility testing and Vitek-2™: is it really useless? Girardello, Raquel; Cury, Ana Paula; Franco, Maria Renata Gomes ...
Diagnostic microbiology and infectious disease,
August 2018, 2018-Aug, 2018-08-00, 20180801, Letnik:
91, Številka:
4
Journal Article
Recenzirano
•P. aeruginosa isolates showed high rates of major errors, whereas for A. baumannii isolates, high rates of very major errors were obtained.•The Vitek-2 automated method does not show reliable ...results when evaluating Enterobacter spp.•For isolates with borderline MICs (between 1 and 8), the results obtained by Vitek-2 should be confirmed for all bacterial species.•For K. pneumoniae and E. coli, a good correlation was obtained between the results of Vitek-2 and broth microdilution when evaluated with isolates with ≤0.5 and ≥16 MICs.
To determine the minimum inhibitory concentrations (MICs) of parenteral penicillin and moxifloxacin against Streptococcus pneumoniae strains isolated at a hospital center.
In-vitro, prospective study ...involving 100 S. pneumoniae isolates collected from patients who had been treated, between October of 2008 and July of 2010, at the Hospital das Clínicas complex of the University of São Paulo School of Medicine, located in the city of São Paulo, Brazil. The isolates were obtained from respiratory tract cultures or blood samples unrelated to meningeal infections, and they were tested for penicillin and moxifloxacin susceptibility by E-test. The MIC category interpretations were based on updated standards.
All isolates were fully susceptible to parenteral penicillin (MIC < 2 µg/mL), and, consequently, they were also susceptible to amoxicillin, ampicillin, third/fourth generation cephalosporins, and ertapenem. Of the S. pneumoniae strains, 99% were also susceptible to moxifloxacin, and only one strain showed an MIC = 1.5 µg/mL (intermediate).
Our results showed high susceptibility rates to parenteral penicillin and moxifloxacin among S. pneumoniae isolates unrelated to meningitis, which differs from international reports. Reports on penicillin resistance should be based on updated breakpoints for non-meningitis isolates in order to guide the selection of an antimicrobial therapy and to improve the prediction of the clinical outcomes.
Appropriate use of antimicrobials is essential to improve outcomes in sepsis. The aim of this study was to determine whether the use of a rapid molecular blood test-Septi
(SF) reduces the antibiotic ...consumption through early de-escalation in patients with nosocomial sepsis compared with conventional blood cultures (BCs).
This was a prospective, randomized, superiority, controlled trial conducted at Sao Paulo Heart Institute in the period October 2012-May 2016. Adult patients admitted to the hospital for at least 48 h with a diagnosis of nosocomial sepsis underwent microorganism identification by both SF test and BCs. Patients randomized into the intervention group received antibiotic therapy adjustment according to the results of SF. Patients randomized into the control group received standard antibiotic adjustment according to the results of BCs. The primary endpoint was antimicrobial consumption during the first 14 days after randomization.
A total of 200 patients were included (100 in each group). The intention to treat analysis found no significant differences in median antibiotic consumption. In the subgroup of patients with positive SF and blood cultures (19 and 25 respectively), we found a statistically significant reduction in the median antimicrobial consumption which was 1429 (1071-2000) days of therapy (DOT)/1000 patients-day in the intervention group and 1889 (1357-2563) DOT/1000 patients-day in the control group (
= 0.017), in the median time of antimicrobial de-escalation (8 versus 54 h-
< 0.001), in the duration of antimicrobial therapy (
= 0.039) and in anti-gram-positive antimicrobial costs (
= 0.002). Microorganism identification was possible in 24.5% of patients (45/184) by SF and 21.2% (39/184) by BC (
= 0.45).
This randomized clinical trial showed that the use of a rapid molecular-based pathogen identification test does not reduce the median antibiotic consumption in nosocomial sepsis. However, in patients with positive microbiological tests, the use of Septi
reduced antimicrobial consumption through early de-escalation compared to conventional blood cultures. These results were driven by a reduction in the consumption of antimicrobials used for Gram-positive bacteria.
The trial was registered at ClinicalTrials.gov (NCT01450358) on 12th October 2011.
Abstract The lichen Cladonia verticillaris produces bioactive secondary metabolites, such as fumarprotocetraric (FUM) and protocetraric acids. Species of the genus Cladonia demonstrate anti-tumor, ...anti-inflammatory and antipyretic activities and have been used in folk medicine to treat respiratory diseases (throat irritation, cough, asthma and tuberculosis). The aim of the present study was to evaluate the expectorant and mucolytic activities of fumarprotocetraric acid in albino Swiss mice. FUM was extracted and purified from an acetone extract of C. verticillaris . The phenol red quantification method was used on the bronchoalveolar lavage fluid following the administration of FUM (25, 50 or 100 mg/kg orally or intraduodenally and 12.5, 25 or 50 mg/kg, intraperitoneally) for the evaluation of expectorant activity. Control groups received either saline solution (7.5 mL/kg) or ambroxol (1 mg/kg) through the same administration routes. Antioxidant activity was evaluated using the thiobarbituric acid reactive species assay in mouse lung tissue treated with the FUM at 25, 50 or 100 mg/kg orally, followed by a lipopolysaccharide solution at 1 mg/kg intrapleurally. The same protocol was used for the control groups using either saline solution (7.5 mL/kg, orally) or N-acetylcysteine (20 mg/kg, orally). Results: Orally administered FUM at doses of 25 and 50 mg/kg promoted significantly greater dose-dependent phenol red activity in the bronchoalveolar lavage and expectorant activity in comparison to the controls ( p < 0.05). Lipid peroxidation (malondialdehyde equivalent) was reduced by 50% in the lung tissue. Conclusion: The results confirm the expectorant and antioxidant properties of fumarprotocetraric acid produced by the lichen C. verticillaris.
Abstract
Background
Healthcare-associated infections (HAIs) are a worldwide concern because of their high morbidity, mortality, and associated costs. Mobile phones (MP) are an important work tool in ...the healthcare setting, but they can be a reservoir of nosocomial pathogens if not carefully cleaned and cause re-contamination of the healthcare professional’s (HCP) hands. We aimed to evaluate bacterial colonization of HCP’s hands and their respective MPs.
Methods
A cross-sectional study was performed in two Intensive Care Units (ICUs), an internal medicine and a burn unit, of a Brazilian tertiary university hospital. These units were chosen because of their different hand hygiene (HH) compliance. We assessed HH and MP handling practices by an electronic inquiry and collected samples from the dominant hand (DH) by the sterile bag technique and of MPs by moistened sterile swab. MALDI-TOF was used for bacterial identification and Dilution Agar (DA) was used to screen Gram-negative bacteria (GNB) susceptibility to carbapenems and colistin.
Results
Forty-seven HCPs were evaluated; of whom, 30% were medical residents, 19% nurses, 17% nurse-technicians, 17% physiotherapists, 13% cleaning staff, and 4% radiology technicians.Overall, 85% of HCPs reported use of MP at work, 26% had never cleaned it, and 34% reported optimal HH compliance practices. All of them believed that MPs can have HAIs agents. DH culture showed 94% of colonization and the most common Gram-positive bacteria (GPB) and GNB were S. epidermidis (n = 17∕44) and A. baumannii complex (n = 11∕44), respectively. MP were colonized in 89% of the cases and the most common GPB and GNB were S. epidermidis (n = 16∕42) and Pseudomonas spp (n = 9∕42), respectively. Overall, in the screening 38% of GNB were resistant to meropenem and 22% to colistin. A. baumannii was the most common meropenem (n = 4) and colistin (n = 2) resistant GNB. In the two units, 32% of HCPs had the same microorganism species isolated in the MP and in the DH (Table 1).
Conclusion
There was a high rate of bacterial colonization on the MP and DH of HCPs and some of these bacteria were carbapenem or colistin resistant. A policy for MP handling in the healthcare setting should be implemented in order to avoid cross-contamination between the MP and the hand of HCPs.
Disclosures
All authors: No reported disclosures.
Abstract
Background
Staphylococcus aureus (Sa) outbreaks are serious infections that if not controlled in time can be life-threating. The aim of this study was to describe the investigation and ...control of a Sa outbreak in an intensive care unit including analysis of MP.
Methods
During a microbiological research of MP conducted in December 2018 in a clinical intensive care unit (ICU) of a tertiary university hospital two patients had an MRSA infection. Since this unit had not reported MRSA infections during the last year it was recognized as an outbreak. The CDC criteria was applied to define MRSA colonization and infection. Hand hygiene (HH) adhesion in this unit was 47%,it has 9 beds and 30 Healthcare professionals (HP). Nasal Swab (NS) of all the HPs and of the patients in the same unit as well. HP’s MP were also analyzed. The samples were subjected to MALDI-TOF (Biomerieux), phenotypical tests, PCR for detection of gene coA and mecA, pulsed-field gel electrophoresis (PFGE), and whole-genome sequence to access resistance, virulence profile and sequence type. Feedback of microbiology results, reinforcement of hand hygiene and MP cleaning was discussed with the unit staff.
Results
A total of 34 samples were collected, 25 were Sa, 13 NS of all HPs and patients, 7 from the MPs and 3 from HPs hands. During the time of the outbreak 5 patients were in the unit.
Patients with infection by MRSA (n = 2), had Methicillin-susceptible Sa in their NSs. Another patient that from the same unit had a MRSA in the NS that when submitted to PFGE was seen to be closely related with the MRSA that originated the outbreak. The patients isolates were assigned to different STs and they had more virulent and resistance genes in comparison with two samples of MPs. The Sa recovered from the MPs belonged to the same ST, same resistance gene and same virulent genes. Figure 1, Table1. Since the feedback to the unit no cases of MRSA have been reported in the last 4 months.
Conclusion
The outbreak was controlled using simply measures (feedback, reinforcement of HH and MP cleaning). The ST398 from the MP has already been described in outbreaks in literature. It seems that MP can be a reservoir for Sa There was more than one Sa lineage in the ICU. Our findings highlighted the need of rethinking the MP cleaning policy in our hospital.
Disclosures
All authors: No reported disclosures.
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