ABSTRACT
Carbohydrate antigen 19-9 (CA 19-9) is a biological marker used to diagnose and monitor the progression of various cancers. Elevated CA 19-9 has also been sporadically observed in Helicobacter pylori infected patients. Similar to H. pylori, animalhosted non-H. pylori Helicobacter (NHPH) species can induce gastroduodenal lesions in humans. We report the first case of CA 19-9 elevation related to H. suis gastritis and its normalisation after eradication. A CA 19-9 screening prescribed as part of a regular check up by the general practitioner was found elevated in a 68-year-old man presenting chronic dyspeptic symptoms. Medical investigations were negative for presence of neoplasia or biliary obstruction. Upper gastrointestinal endoscopy confirmed the presence of chronic gastritis and H. suis was identified in gastric biopsies. The standard treatment for H. pylori successfully eradicated H. suis with normalisation of CA 19-9 levels. In addition to H. pylori, infection with NHPH species should be considered as an additional cause of elevated CA19-9.
Subject(s)
Gastritis , Helicobacter Infections , Helicobacter heilmannii , Helicobacter pylori , Intraabdominal Infections , Aged , Carbohydrates , Gastritis/diagnosis , Gastritis/drug therapy , Helicobacter Infections/diagnosis , Helicobacter Infections/drug therapy , Helicobacter Infections/pathology , Humans , MaleABSTRACT
BACKGROUND: This study aimed to compare four anti-SARS-CoV-2 immunoassays in populations presenting different clinical severity levels. METHODS: Three populations were included: "severe-to-critical" ICU-hospitalized patients (n = 18), "mild-to-moderate" hospitalized patients (n = 16) and non-hospitalized symptomatic patients (n = 24). Four commercial immunoassays were analyzed and validated: anti-IgG ARCHITECT® (Abbott), anti-Total antibodies (Ab) VITROS® (Ortho Clinical Diagnostics), anti-IgG NovaLisa® (NovaTec Immundiagnostica) and Healgen® IgM and IgG (Zhejiang Orient Gene Biotech). Sensitivities were evaluated according to days post-symptoms onset (pso). Specificities were evaluated on SARS-CoV-2-negative control sera collected before January 2020. RESULTS: A majority of severe-to-critically ill patients showed detectable Ab already at day 14 and sensitivities reached 100 % after 22 days pso. For patients with "mild-to-moderate" illness, sensitivities increased by at least 5-fold from day 0 to day 14 pso. Non-hospitalized symptomatic individuals already seroconverted at day 14 days pso with 100 % sensitivities for Total Ab VITROS®. Specificities were evaluated at 97 % for ARCHITECT® and NovaLisa®, 98 % for VITROS® and at 94 % for Healgen® combined IgM and IgG. Five "severe-to-critically" ill patients presented high positive Ab levels for at least 16 weeks pso. CONCLUSION: The Ab levels and the evaluated sensitivities, representing the true positive rate, increased overtime and were related to the COVID-19 severity. Automated Total Ab immunoassay showed better sensitivities and specificity for immunological surveillance and vaccine evaluation.
Subject(s)
Antibodies, Viral/blood , COVID-19 Serological Testing/methods , COVID-19/diagnosis , Immunoassay/methods , Humans , SARS-CoV-2/immunology , SARS-CoV-2/isolation & purification , Sensitivity and SpecificitySubject(s)
Abscess/drug therapy , Anti-Bacterial Agents/therapeutic use , Bacterial Infections/drug therapy , Cephalosporins/therapeutic use , Drug Resistance, Multiple, Bacterial , Pancreatitis/drug therapy , Abscess/diagnosis , Bacteremia/diagnosis , Bacteremia/drug therapy , Bacterial Infections/diagnosis , Compassionate Use Trials , Humans , Klebsiella pneumoniae/isolation & purification , Male , Middle Aged , Pancreatitis/diagnosis , Pseudomonas aeruginosa/isolation & purification , Staphylococcus aureus/isolation & purification , Treatment Outcome , CefiderocolABSTRACT
In this Letter, we propose a convenient method of generating an optical vortex (OV) array, in which the size and quantity can be controlled by employing vortex phase plates, a mode converter, and a spatial light modulator into a simple optical system. Different sizes of OV arrays are generated from the superposition of crossed Hermite-Gaussian (HG) modes possessing equal or unequal orders and mutually orthogonal circular polarizations. We experimentally and theoretically demonstrate a series of vector superposed optical fields. Here the sizes of the OV arrays, as well as the quantities of OVs, are defined in terms of specific sets of HG bases. Our results indicate that a simple setup can be used to effectively generate and control OVs and OV arrays.
ABSTRACT
BACKGROUND: Enterobacteriaceae are recognized as leading pathogens of healthcare-associated infections. AIM: To report the investigation of a nosocomial outbreak of extended-spectrum ß-lactamase-producing Enterobacter cloacae affecting cardiothoracic surgery patients in a Belgian academic hospital. METHODS: Cases were defined based on epidemiological and microbiological investigations, including molecular typing using repetitive element-based polymerase chain reaction and multi-locus sequence typing. Case-control studies followed by field evaluations allowed the identification of a possible reservoir, and the retrospective assessment of human and financial consequences. FINDINGS: Over a three-month period, 42 patients were infected or colonized by CTX-M-15-producing E. cloacae strains that belonged to the same clonal lineage. Acquisition mainly occurred in the intensive care unit (N = 23) and in the cardiothoracic surgery ward (N = 16). All but one patient had, prior to acquisition, undergone a cardiothoracic surgical procedure, monitored by the same transoesophageal echocardiography (TOE) probe in the operating room. Despite negative microbiological culture results, the exclusion of the suspected probe resulted in rapid termination of the outbreak. Overall, the outbreak was associated with a high mortality rate among infected patients (40%) as well as significant costs (266,550). CONCLUSION: The outbreak was indirectly shown to be associated with the contamination of a manually disinfected TOE probe used per-operatively during cardiothoracic surgery procedures, because withdrawal of the putative device led to rapid termination of the outbreak.
Subject(s)
Cross Infection/epidemiology , Disease Outbreaks , Enterobacter cloacae/isolation & purification , Enterobacteriaceae Infections/epidemiology , Thoracic Surgical Procedures/adverse effects , Aged , Aged, 80 and over , Belgium/epidemiology , Case-Control Studies , Cross Infection/microbiology , Echocardiography, Transesophageal/adverse effects , Enterobacter cloacae/classification , Enterobacter cloacae/enzymology , Enterobacter cloacae/genetics , Enterobacteriaceae Infections/microbiology , Female , Genotyping Techniques , Humans , Male , Middle Aged , Multilocus Sequence Typing , Retrospective Studies , beta-Lactamases/metabolismABSTRACT
We propose an efficient and robust method to generate the kaleidoscope vortex beam by employing an astigmatic laser cavity with an extra-cavity cylindrical lens. The kaleidoscope vortex beam is arising from the superposition of Laguerre-Gaussian modes with the longitudinal-transverse coupling effect in the laser cavity. The superposed Laguerre-Gaussian mode leads to the formation of complex phase singularities and implies the participation of different optical orbital angular momentum involved in a single kaleidoscope vortex beam. We experimentally demonstrate that a series of kaleidoscope vortex beams with different symmetry are systematically achieved by using a simple setup. The output power of the laser is dependent on the cavity length. This approach is expected to create high-order optical vortex beams and pave the way for optical entanglement.
ABSTRACT
The purpose of this study was evaluation of the VAPChip assay based on the "Rapid-Array-PCR-technology" which targets 13 respiratory pathogens and 24 ß-lactam resistance genes directly on respiratory clinical specimens. The first step included analysis of 45 respiratory specimens in order to calibrate and determine the threshold for target genes. The second prospective step involved 85 respiratory samples from patients suspected of nosocomial pneumonia collected in two academic hospitals over an 8-month period. Results of the VAPChip assay were compared to routine methods. The first step showed a large proportion of positive signals for H. influenzae and/or S. pneumoniae. For identification, discrepancies were observed in seven samples. Thresholds were adapted and two probes were re-designed to create a new version of the cartridge. In the second phase, sensitivity and specificity of the VAPchip for bacterial identification were 72.9% and 99.1%, respectively. Seventy (82%) pathogens were correctly identified by both methods. Nine pathogens detected by the VAPChip were culture negative and 26 pathogens identified by culture were VAPChip negative. For resistance mechanisms, 11 probes were positive without identification of pathogens with an antimicrobial-susceptibility testing compatible by culture. However, the patient's recent microbiological history was able to explain most of these positive signals. The VAPChip assay simultaneously detects different pathogens and resistance mechanisms directly from clinical samples. This system seems very promising but the extraction process needs to be automated for routine implementation. This kind of rapid point-of-care automated platform permitting a syndromic approach will be the future challenge in the management of infectious diseases.
Subject(s)
Cross Infection/diagnosis , Haemophilus influenzae/isolation & purification , Molecular Diagnostic Techniques/methods , Pneumonia, Bacterial/diagnosis , Real-Time Polymerase Chain Reaction/methods , Streptococcus pneumoniae/isolation & purification , Cross Infection/microbiology , DNA, Bacterial/genetics , Haemophilus influenzae/classification , Haemophilus influenzae/drug effects , Haemophilus influenzae/genetics , Humans , Pneumonia, Bacterial/microbiology , Proof of Concept Study , Prospective Studies , Sensitivity and Specificity , Streptococcus pneumoniae/classification , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/genetics , beta-Lactam Resistance/geneticsSubject(s)
Agricultural Workers' Diseases/microbiology , Bacterial Proteins/genetics , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Staphylococcal Infections/microbiology , Aged , Agricultural Workers' Diseases/drug therapy , Animals , Anti-Bacterial Agents/adverse effects , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Bacterial Proteins/drug effects , Belgium , Drug Resistance, Multiple, Bacterial , Gene Transfer, Horizontal , Humans , Male , Methicillin-Resistant Staphylococcus aureus/drug effects , Methicillin-Resistant Staphylococcus aureus/genetics , Microbial Sensitivity Tests , Postoperative Complications/drug therapy , Postoperative Complications/microbiology , Soft Tissue Infections/drug therapy , Soft Tissue Infections/microbiology , Staphylococcal Infections/drug therapy , Staphylococcal Skin Infections/drug therapy , Staphylococcal Skin Infections/microbiology , Zoonoses/microbiologyABSTRACT
Carbapenemase-producing Enterobacteriaceae are increasingly reported worldwide. The aim of the study was to determine the incidence and molecular epidemiology of carbapenemase-producing (CP) Escherichia coli and Klebsiella pneumoniae (CP-E/K) in Belgium. Eleven hospital-based laboratories collected carbapenem non-susceptible (CNS) isolates of E. coli and K. pneumoniae detected in clinical specimens from January 2013 to December 2014. All CNS strains were tested for carbapenemase production and typed by multilocus sequence typing (MLST) for a 6-month period as part of the European Survey on Carbapenemase-Producing Enterobacteriaceae in Europe (EuSCAPE) structured survey. In addition, an equal number of carbapenem-susceptible isolates collected were preserved as a control group for risk factor analysis. The overall incidence rate of CP-E/K isolates in hospitals increased from 0.124 in 2013 to 0.223 per 1000 admissions in 2014. From November 2013 to April 2014, 30 CP K. pneumoniae [OXA-48 (n = 16), KPC (n = 13), OXA-427 (n = 1)] and five CP E. coli [OXA-48 (n = 3), NDM (n = 1), OXA-427 (n = 1)] isolates were detected in ten hospitals. The 16 OXA-48-producing K. pneumoniae strains were distributed into eight sequence types (STs), while the 13 KPC-producing K. pneumoniae clustered into three STs dominated by ST512 (n = 7) and ST101 (n = 5). Compared to controls, we observed among CP-E/K carriers significantly higher proportion of males, respiratory origins, previous hospitalization, nosocomial setting, and a significantly lower proportion of bloodstream infections. Our study confirms the rapid spread of CP-E/K in Belgian hospitals and the urgent need for a well-structured and coordinated national surveillance plan in order to limit their dissemination.
Subject(s)
Bacterial Proteins/analysis , Escherichia coli Infections/epidemiology , Escherichia coli/enzymology , Klebsiella Infections/epidemiology , Klebsiella pneumoniae/enzymology , beta-Lactamases/analysis , Adolescent , Adult , Aged , Aged, 80 and over , Belgium/epidemiology , Child , Child, Preschool , Cluster Analysis , Escherichia coli/classification , Escherichia coli/genetics , Escherichia coli/isolation & purification , Escherichia coli Infections/microbiology , Female , Hospitals , Humans , Incidence , Infant , Infant, Newborn , Klebsiella Infections/microbiology , Klebsiella pneumoniae/classification , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/isolation & purification , Male , Middle Aged , Molecular Epidemiology , Multilocus Sequence Typing , Time Factors , Young AdultABSTRACT
We propose and experimentally demonstrate a new complex laser beam with inhomogeneous polarization distributions mapping onto high-order Poincaré spheres (HOPSs). The complex laser mode is achieved by superposition of Laguerre-Gaussian modes and manifests exotic flower-like localization on intensity and phase profiles. A simple optical system is used to generate a polarization-variant distribution on the complex laser mode by superposition of orthogonal circular polarizations with opposite topological charges. Numerical analyses of the polarization distribution are consistent with the experimental results. The novel flower HOPS beams can act as a new light source for photonic applications.
ABSTRACT
We present the case of a 70-year-old non-diabetic patient who presented to the emergency department with unrelenting otalgia. A severe otitis externa (OE) and mastoiditis were treated with broad spectrum antibiotics and surgical drainage. No bacteria was isolated from surgical samples. Because the otalgia persisted, a magnetic resonance (MR) was performed and showed an infiltrating process at the skull base. Biopsies failed to prove malignancy or granulomatosis. The patient's neurological state deteriorated. The suspicion of a skull base osteomyelitis (SBO) was raised and proven by CT-guided biopsies that grew Pseudomonas aeruginosa. Meropenem and ciprofloxacin, given for 8 weeks, lead to a fast clinical improvement and a full recovery. SBO is uncommon, often complicating severe OE. Pseudomonas aeruginosa is the main pathogen. Prompt diagnosis and adequate antibiotherapy are required to lower mortality and morbidity. The diagnosis may be delayed because of unawareness and large differential diagnosis including solid neoplasic tumours, malignant hemopathies and granulomatosis.
Subject(s)
Osteomyelitis/diagnosis , Pseudomonas Infections/diagnosis , Skull Base , Aged , Anti-Bacterial Agents/administration & dosage , Ciprofloxacin/administration & dosage , Delayed Diagnosis , Earache/etiology , Humans , Magnetic Resonance Imaging , Male , Meropenem , Osteomyelitis/complications , Osteomyelitis/microbiology , Skull Base/microbiology , Thienamycins/administration & dosageABSTRACT
The purpose of this investigation was to compare several phenotypic methods, including combined disk tests (CDT) containing metallo-ß-lactamase (MBL) inhibitors or cloxacillin, and the Carba NP test for the detection of carbapenemase-producing Pseudomonas aeruginosa (CPPA). A new CDT using imipenem (10 µg) ± cloxacillin 4,000 µg and the Carba NP test were evaluated to detect CPPA. In addition, four commercially available combined disks containing a carbapenem and ethylene-diamine-tetra-acetic acid (EDTA) or dipicolinic acid (DPA) as the inhibitor were tested in order to detect MBL-positive P. aeruginosa. All these phenotypic methods were evaluated on 188 imipenem non-susceptible P. aeruginosa (CPPA, n = 75) isolates divided into 26 well-characterized collection strains and 162 non-duplicate clinical isolates referred to the national reference laboratory in 2013. For the total of 188 isolates tested, CDT containing EDTA or DPA displayed high sensitivities (99%) and specificities (95%) for detecting MBL-producing isolates. CDT with cloxacillin showed a sensitivity and specificity of 97%/96% compared to 88%/99% for the Carba NP test in order to detect CPPA. For the 162 clinical isolates, CDT containing EDTA or DPA displayed a high negative predictive value (NPV) (99%) for detecting MBL-producing isolates. CDT with cloxacillin showed an NPV of 98%, compared to 95% for the Carba NP test in order to detect CPPA. In our setting, CDT associating imipenem ± EDTA or ± DPA performed best for the detection of MBL-producing P. aeruginosa. Imipenem/imipenem-cloxacillin test yielded good NPV to exclude the presence of MBL in imipenem non-susceptible isolates.
Subject(s)
Bacterial Proteins/biosynthesis , Phenotype , Pseudomonas Infections/diagnosis , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/classification , Pseudomonas aeruginosa/isolation & purification , beta-Lactamases/biosynthesis , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , Enzyme Activation , Humans , Microbial Sensitivity Tests/methods , Pseudomonas aeruginosa/drug effects , Reproducibility of Results , Sensitivity and Specificity , beta-Lactamases/geneticsABSTRACT
BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CPE) are emerging worldwide, representing a major threat for public health. Early CPE detection is crucial in order to prevent infections and the development of reservoirs/outbreaks in hospitals. In 2008, most of the CPE strains reported in Belgium were imported from patients repatriated from abroad. Actually, this is no longer the case. OBJECTIVES AND METHODS: A surveillance was set up in Belgian hospitals (2012) in order to explore the epidemiology and determinants of CPE, including the link with international travel/hospitalization. The present article describes travel-related CPE reported in Belgium. Different other potential sources for importation of CPE are discussed. RESULTS: Only 12% of all CPE cases reported in Belgium (2012-2013) were travel related (with/without hospitalization). This is undoubtedly an underestimation (missing travel data: 36%), considering the increasing tourism, the immigration from endemic countries, the growing number of foreign patients using scheduled medical care in Belgium, and the medical repatriations from foreign hospitals. The free movement of persons and services (European Union) contributes to an increase in foreign healthcare workers (HCW) in Belgian hospitals. Residents from nursing homes located at the country borders can be another potential source of dissemination of CPE between countries. Moreover, the high population density in Belgium can increase the risk for CPE-dissemination. Urban areas in Belgium may cumulate these potential risk factors for import/dissemination of CPE. CONCLUSIONS: Ideally, travel history data should be obtained from hospital hygiene teams, not from the microbiological laboratory. Patients who received medical care abroad (whatever the country) should be screened for CPE at admission.
Subject(s)
Bacterial Proteins/metabolism , Cross Infection , Enterobacteriaceae Infections , Enterobacteriaceae , Infection Control , Travel , beta-Lactamases/metabolism , Belgium/epidemiology , Cross Infection/diagnosis , Cross Infection/etiology , Cross Infection/prevention & control , Enterobacteriaceae/isolation & purification , Enterobacteriaceae/metabolism , Enterobacteriaceae Infections/diagnosis , Enterobacteriaceae Infections/etiology , Enterobacteriaceae Infections/prevention & control , Humans , Infection Control/organization & administration , Infection Control/statistics & numerical data , Microbial Sensitivity Tests , Needs Assessment , Risk AssessmentABSTRACT
Resistance to third-generation cephalosporins in Gram-negative bacteria is emerging in Asia. We report the prevalence and distribution of extended-spectrum beta-lactamase (ESBL), AmpC beta-lactamase and carbapenemase-coding genes in cefotaxime-resistant Enterobacteriaceae isolates from bloodstream infections (BSI) in Cambodia. All Enterobacteriaceae isolated from BSI in adult patients at Sihanouk Hospital Centre of HOPE, Phnom Penh, Cambodia (2007-2010) were assessed. Antimicrobial susceptibility testing was carried out by disc diffusion and MicroScan according to Clinical and Laboratory Standards Institute (CLSI) guidelines. Screening for ESBL, plasmidic AmpC and carbapenemase-coding genes was performed by multiplex polymerase chain reaction (PCR) sequencing assays. Identification of the ST131 clone was performed in all CTX-M-positive Escherichia coli, using PCR targeting the papB gene. Out of 183 Enterobacteriaceae, 91 (49.7 %) isolates (84 BSI episodes) were cefotaxime-resistant: E. coli (n = 68), Klebsiella pneumoniae (n = 17) and Enterobacter spp. (n = 6). Most episodes were community-acquired (66/84; 78.3 %). ESBLs were present in 89/91 (97.8 %) cefotaxime-resistant isolates: 86 (96.6 %) were CTX-M, mainly CTX-M-15 (n = 41) and CTX-M-14 (n = 21). CTX-M of group 1 were frequently associated with TEM and/or OXA-1/30 coding genes and with phenotypic combined resistance to ciprofloxacin, sulphamethoxazole-trimethoprim and gentamicin (39/50, 78.0 %). Plasmidic AmpC (CMY-2 and DHA-1 types) were found alone (n = 2) or in combination with ESBL (n = 4). Eighteen E. coli isolates were identified as B2-ST131-O25B: 11 (61.1 %) carried CTX-M-14. No carbapenemase-coding genes were detected. ESBL among Enterobacteriaceae from BSI in Cambodia is common, mainly associated with CTX-M-15 and CTX-M-14. These findings warrant urgent action for the containment of antibiotic resistance in Cambodia.
Subject(s)
Anti-Bacterial Agents/pharmacology , Bacteremia/epidemiology , Cephalosporins/pharmacology , Enterobacteriaceae Infections/epidemiology , Enterobacteriaceae/enzymology , beta-Lactam Resistance , beta-Lactamases/genetics , Adolescent , Adult , Aged , Bacteremia/microbiology , Cambodia/epidemiology , Cefotaxime/pharmacology , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/microbiology , Escherichia coli , Female , Humans , Klebsiella pneumoniae , Male , Microbial Sensitivity Tests , Middle Aged , Multiplex Polymerase Chain Reaction , Prevalence , Prospective Studies , Sequence Analysis, DNA , Young AdultABSTRACT
OBJECTIVES: To validate and accredit a set of three multiplex endpoint PCR assays, targeting the most important carbapenemase and minor extended-spectrum ß-lactamase (ESBL) resistance genes, according to the international ISO 15189 particular requirements for the quality and competence of medical laboratories. METHODS: Specific primers targeting ESBLs and carbapenemases were collected from the literature or designed internally. The multiplex PCRs were validated for sensitivity, specificity, intra- and inter-run reproducibility and accuracy by means of external quality control (EQC) using a collection of 137 characterized and referenced isolates. For each multiplex PCR assay, the presence of an extraction control ruled out false-negative results due to PCR inhibition or extraction faults. Amplicons were separated by capillary electrophoresis (QIAxcel system, Qiagen). The protocols and validation files were reviewed in the setting of an external audit conducted by the Belgian organization for accreditation (BELAC). RESULTS: Sensitivity, specificity and reproducibility for each targeted gene were 100%. All isolates from the three EQC panels were correctly identified by each PCR assay (accuracy 100%). The validation files were controlled by BELAC, and the PCR protocols were accepted as accredited according to ISO 15189. CONCLUSIONS: Three home-made multiplex PCRs targeting the major carbapenemases and four minor class A ESBL genes encountered in Gram-negative bacteria were accredited according to the ISO 15189 standards. This validation scheme could provide a useful model for laboratories aiming to accredit their own protocols.
Subject(s)
Gram-Negative Bacteria/enzymology , Molecular Diagnostic Techniques/methods , Multiplex Polymerase Chain Reaction/methods , beta-Lactamases/genetics , Electrophoresis, Capillary/methods , Gram-Negative Bacteria/genetics , Humans , Molecular Diagnostic Techniques/standards , Multiplex Polymerase Chain Reaction/standards , Reference Standards , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
OBJECTIVES: Rapid diagnosis and appropriate empirical antimicrobial therapy before the availability of conventional microbiological results is of pivotal importance for the clinical outcome of ventilator-associated pneumonia (VAP). We evaluated the VAPChip, a novel, closed cartridge molecular tool aiming to identify directly from clinical samples and within a working day the principal bacteria causative of VAP as well as clinically relevant ß-lactam resistance genes. METHODS: The Real-time Array PCR for Infectious Diseases (RAP-ID) is a novel technology that combines multiplex PCR with real-time microarray detection. The VAPChip is a closed cartridge kit adapted to the RAP-ID instrument that targets 13 key respiratory pathogens causative of VAP and 24 relevant antimicrobial resistance genes that mediate resistance to ß-lactam agents, including extended-spectrum cephalosporins and carbapenems. Analytical validation of the VAPChip was carried out blindly on a collection of 292 genotypically characterized bacterial reference and clinical isolates, including 225 isolates selected on the basis of their species identification and antimicrobial resistance profiles and 67 bacterial isolates belonging to the oropharyngeal flora not targeted by the array. RESULTS: The limit of detection of the assay lies between 10 and 100 genome copies/PCR and the dynamic range is five orders of magnitude permitting at least semi-quantitative reporting of the results. Sensitivity, specificity and negative and positive predictive values ranged from 95.8% to 100% for species identification and detection of resistance genes. CONCLUSIONS: VAPChip is a novel diagnostic tool able to identify resistant bacterial isolates by RAP-ID technology. The results of this analytical validation have to be confirmed on clinical specimens.
Subject(s)
Bacteria/classification , Bacteria/isolation & purification , Drug Resistance, Bacterial , Multiplex Polymerase Chain Reaction/methods , Pneumonia, Ventilator-Associated/microbiology , Real-Time Polymerase Chain Reaction/methods , Bacteria/drug effects , Bacteria/genetics , DNA, Bacterial/genetics , Microarray Analysis/methods , Time FactorsABSTRACT
BACKGROUND: Recommendations were applied before and during the Belgian pandemic (2009) H1N1 influenza wave at a university hospital (420 beds), for optimizing isolation processes and therapeutic management of possible and confirmed infected cases. METHODS: All patients presenting to the Emergency Department (ED) between August 1st and December 31st 2009 were screened for ILI symptoms, and were isolated for clinical assessment in case of positive screening. Patients categorized as possible influenza cases and who required hospitalization were isolated in dedicated wards. Specific diagnostic algorithms were implemented. Medical charts were retrospectively reviewed and matched with results of the microbiology laboratory. Patient's characteristics were analyzed, the contribution of laboratory diagnosis on therapy and lengh of stay (LOS) in isolation was also assessed. RESULTS: 310 patients out of 6068 had a positive screening for ILI, of these, 265 were retained as possible influenza cases and 139 required hospitalization. Twenty-eight children (8 requiring hospitalization) and 20 hospitalized adult patients had confirmed influenza infection. Five adult patients were admitted to the intensive care unit (ICU), 3 requiring extracorporeal membrane oxygenation (ECMO). There was no death related to the new influenza strain. The majority of confirmed patients were diagnosed during the Belgian epidemic wave, with a sensitivity of antigen detection of 50% in children and 35% in adults comparatively to real-time PCR (RT-PCR). CONCLUSIONS: The impact of (2009) H1N1 pandemic influenza remained limited, except for ICU patients requiring ECMO. Implementation of screening, isolation, and virological diagnosis processes led to significant improvement of patient management.
Subject(s)
Influenza A Virus, H1N1 Subtype , Influenza, Human/epidemiology , Pandemics , Adolescent , Adult , Aged , Aged, 80 and over , Belgium/epidemiology , Child , Child, Preschool , Hospitalization , Hospitals, University , Humans , Infant , Influenza, Human/diagnosis , Influenza, Human/therapy , Influenza, Human/virology , Middle Aged , Young AdultSubject(s)
Bacterial Proteins/metabolism , Communicable Diseases, Emerging/microbiology , Enterobacteriaceae Infections/microbiology , Enterobacteriaceae/enzymology , beta-Lactamases/metabolism , Anti-Bacterial Agents/pharmacology , Belgium , Carbapenems/pharmacology , Drug Resistance, Bacterial , Enterobacteriaceae/drug effects , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/epidemiology , Hospitals/statistics & numerical data , Humans , Longitudinal Studies , Microbial Sensitivity Tests , Polymerase Chain ReactionABSTRACT
The identification of Nocardia species, usually based on biochemical tests together with phenotypic in vitro susceptibility and resistance patterns, is a difficult and lengthy process owing to the slow growth and limited reactivity of these bacteria. In this study, a panel of 153 clinical and reference strains of Nocardia spp., altogether representing 19 different species, were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). As reference methods for species identification, full-length 16S rRNA gene sequencing and phenotypical biochemical and enzymatic tests were used. In a first step, a complementary homemade reference database was established by the analysis of 110 Nocardia isolates (pretreated with 30 min of boiling and extraction) in the MALDI BioTyper software according to the manufacturer's recommendations for microflex measurement (Bruker Daltonik GmbH, Leipzig, Germany), generating a dendrogram with species-specific cluster patterns. In a second step, the MALDI BioTyper database and the generated database were challenged with 43 blind-coded clinical isolates of Nocardia spp. Following addition of the homemade database in the BioTyper software, MALDI-TOF MS provided reliable identification to the species level for five species of which more than a single isolate was analyzed. Correct identification was achieved for 38 of the 43 isolates (88%), including 34 strains identified to the species level and 4 strains identified to the genus level according to the manufacturer's log score specifications. These data suggest that MALDI-TOF MS has potential for use as a rapid (<1 h) and reliable method for the identification of Nocardia species without any substantial costs for consumables.
Subject(s)
Bacteriological Techniques/methods , Nocardia/chemistry , Nocardia/isolation & purification , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Bacterial Typing Techniques , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , DNA, Ribosomal/chemistry , DNA, Ribosomal/genetics , Germany , Humans , Nocardia/classification , Nocardia Infections/diagnosis , Nocardia Infections/microbiology , RNA, Ribosomal, 16S/genetics , Sensitivity and Specificity , Sequence Analysis, DNAABSTRACT
OBJECTIVES: To investigate the presence of extended-spectrum beta-lactamases (ESBLs) among Pseudomonas aeruginosa clinical isolates referred to two Belgian reference laboratories. METHODS: Antibiograms were analysed for P. aeruginosa isolates referred between 2004 and 2008. Isolates resistant to ceftazidime (MIC > 8 mg/L) and with a positive double-disc synergy test between ceftazidime and clavulanate were serotyped and screened for the presence of ESBL-encoding genes. Genes encoding metallo-beta-lactamases (bla(MBL)) were sought by PCR in ESBL-producing isolates with positive imipenem/EDTA synergy tests. PFGE of SpeI-digested genomic DNA was used to compare isolates and selected strains were characterized by multilocus sequence typing. RESULTS: Forty-eight (2.2%) of 2150 P. aeruginosa isolates were confirmed as class A ESBL-producing isolates by molecular testing. bla(BEL) and bla(PER) alleles were detected, respectively, in 39 and 10 P. aeruginosa isolates originating from 16 hospitals (two isolates were simultaneously positive for BEL and PER). Fifteen of the isolates were found to co-produce ESBLs and VIM carbapenemases. These strains were pan-resistant and remained susceptible only to colistin (MICs Subject(s)
Bacterial Proteins/biosynthesis
, Pseudomonas Infections/microbiology
, Pseudomonas aeruginosa/enzymology
, beta-Lactamases/biosynthesis
, Anti-Bacterial Agents/pharmacology
, Bacterial Proteins/genetics
, Belgium
, Cluster Analysis
, DNA Fingerprinting
, Electrophoresis, Gel, Pulsed-Field
, Genes, Bacterial
, Genotype
, Hospitals
, Humans
, Microbial Sensitivity Tests
, Molecular Sequence Data
, Pseudomonas aeruginosa/classification
, Pseudomonas aeruginosa/genetics
, Pseudomonas aeruginosa/isolation & purification
, Sequence Analysis, DNA
, Serotyping
, beta-Lactamases/genetics