ABSTRACT
We have previously studied carbapenem non-susceptible Pseudomonas aeruginosa (CNPA) strains from intensive care units (ICUs) in a referral hospital in Jakarta, Indonesia (Pelegrin et al., 2019). We documented that CNPA transmissions and acquisitions among patients were variable over time and that these were not significantly reduced by a set of infection control measures. Three high risk international CNPA clones (sequence type (ST)235, ST823, ST357) dominated, and carbapenem resistance was due to carbapenemase-encoding genes and mutations in the porin OprD. Pelegrin et al. (2019) reported core genome analysis of these strains. We present a more refined and detailed whole genome-based analysis of major clones represented in the same dataset. As per our knowledge, this is the first study reporting Single Nucleotide Polymorphisms (wgSNP) analysis of Pseudomonas strains. With whole genome-based Multi Locus Sequence Typing (wgMLST) of the 3 CNPA clones (ST235, ST357 and ST823), three to eleven subgroups with up to 200 allelic variants were observed for each of the CNPA clones. Furthermore, we analyzed these CNPA clone clusters for the presence of wgSNP to redefine CNPA transmission events during hospitalization. A maximum number 35350 SNPs (including non-informative wgSNPs) and 398 SNPs (ST-specific_informative-wgSNPs) were found in ST235, 34,570 SNPs (including non-informative wgSNPs) and 111 SNPs (ST-specific_informative-wgSNPs) in ST357 and 26,443 SNPs (including non-informative SNPs) and 61 SNPs (ST-specific_informative-wgSNPs) in ST823. ST-specific_Informative-wgSNPs were commonly noticed in sensor-response regulator genes. However, the majority of non-informative wgSNPs was found in conserved hypothetical proteins or in uncharacterized proteins. Of note, antibiotic resistance and virulence genes segregated according to the wgSNP analyses. A total of 8 transmission chains for ST235 strains followed by 9 and 4 possible transmission chains for ST357 and ST823 were traceable on the basis of pairwise distances of informative-wgSNPs (0 to 4 SNPs) among the strains. The present study demonstrates the value of detailed whole genome sequence analysis for highly refined epidemiological analysis of P. aeruginosa.
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Although often overlooked, the use of disinfectants can lead to antimicrobial resistance and this may exacerbate resistance to antibiotics. Here, we explain why all antimicrobial agents, including disinfectants, should be used prudently in a way that is guided by evidence.
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PURPOSE: To evaluate a low-cost multimodal intervention on the acquisition of carbapenem-non-susceptible Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa by patients in low-resource intensive care units. MATERIALS AND METHODS: We performed a quasi-experimental study in a referral hospital in Jakarta, Indonesia: pre-intervention phase 1 (2013-2014), intervention phase 2 (2014-2015) and post-intervention phase 3 (2015-2016). The intervention was hand hygiene promotion and environmental cleaning and disinfection combined with patient disinfection and cohorting. The primary outcome was acquisition of resistant bacteria per 100 patient-days at risk, which was assessed by active microbiological surveillance and analysed with a multilevel Poisson segmented regression model. RESULTS: In phase 1 (387 patients), the acquisition rate was 4.3/100 days for carbapenem-non-susceptible A. baumannii versus 1.1/100 days for both K. pneumoniae and P. aeruginosa. There was a significant step change from phase 1 to phase 3 (361 patients) in the acquisition of carbapenem-non-susceptible strains, the incidence rate ratio (IRR) was 0.343 (99%CI: 0.164-0.717). This significant change was mainly due to reduced acquisitions of resistant A. baumannii (IRR 0.4, 99%CI: 0.181-1.061). Negative confounding was observed. CONCLUSION: A multimodal intervention to prevent acquisition of resistant pathogens is feasible and may be effective in ICUs in lower-middle income countries.
Subject(s)
Acinetobacter baumannii , Cross Infection , Anti-Bacterial Agents , Carbapenems/pharmacology , Cross Infection/epidemiology , Cross Infection/prevention & control , Gram-Negative Bacteria , Hospitals , Humans , Indonesia/epidemiology , Intensive Care Units , Interrupted Time Series Analysis , Microbial Sensitivity Tests , Referral and ConsultationABSTRACT
BACKGROUND: Intensive care units (ICUs) in lower-middle income countries (LMICs) are suspected to constitute a special risk for patients of acquiring infection due to multiple antibiotic resistant organisms. The aim of this systematic scoping review was to present the data published on ICU-acquired infections and on antimicrobial resistance observed in ICUs in LMICs over a 13-year period. A systematic scoping review was conducted according to the PRISMA extension guideline for scoping reviews and registered in the Open Science Framework. Articles were sought that reported on ICU-acquired infection in LMICs between 2005 and 2018. Two reviewers parallelly reviewed 1961 titles and abstracts retrieved from five data banks, found 274 eligible and finally included 51. Most LMICs had not produced reports in Q1 or Q2 journals in this period, constituting a large gap in knowledge. However, from the reported evidence it is clear that the rate of ICU-acquired infections was comparable, albeit approximately 10% higher, in LMICs compared to high income countries. In contrast, ICU mortality was much higher in LMICs (33.6%) than in high income countries (< 20%). Multidrug-resistant Gram-negative species, especially Acinetobacter baumannii and Pseudomonas aeruginosa, and Klebsiella pneumoniae played a much more dominant role in LMIC ICUs than in those in high income countries. However, interventions to improve this situation have been shown to be feasible and effective, even cost-effective. CONCLUSIONS: Compared to high income countries the burden of ICU-acquired infection is higher in LMICs, as is the level of antimicrobial resistance; the pathogen distribution is also different. However, there is evidence that interventions are feasible and may be quite effective in these settings. Protocol Registration The protocol was registered with Open Science Framework ( https://osf.io/c8vjk ).
Subject(s)
Bacterial Infections/epidemiology , Cross Infection/epidemiology , Developing Countries , Drug Resistance, Bacterial , Intensive Care Units , Acinetobacter baumannii , Adult , Humans , Klebsiella pneumoniae , Pseudomonas aeruginosaABSTRACT
OBJECTIVE: A prospective observational study was performed to assess the epidemiology and clinical impact of carbapenem-non-susceptible Klebsiella pneumoniae (CNKP) in intensive care units (ICUs) of the national referral hospital in Jakarta, Indonesia. MATERIALS/METHODS: Adult patients consecutively hospitalized for > 48 h in two ICUs of the national referral hospital were included from April until October 2013 and from April until August 2014. K. pneumoniae from clinical cultures and standardized screening of rectum and throat on admission, discharge and weekly if hospitalized > 7 days were collected. Environmental niches and healthcare workers (HCWs) were also screened. Susceptibility was determined phenotypically and the presence of carbapenemase genes by PCR. Raman spectroscopy as well as multiple-locus variable number tandem repeat analysis (MLVA) were used for typing. RESULTS: Twenty-two out of 412 (5.3%) patients carried CNKP on admission and 37/390 (9.5%) acquired CNKP during ICU stay. The acquisition rate was 24.7/1000 patient-days at risk. One out of 31 (3.2%) environmental isolates was a CNKP. None of the HCWs carried CNKP. Acquisition of CNKP was associated with longer ICU stay (adjusted Hazard Ratio: 2.32 [CI99: 1.35-3.68]). ICU survival was lower among patients with CNKP compared to patients with carbapenem-susceptible K. pneumoniae (aHR 2.57, p = 0.005). Ninety-six of the 100 (96%) CNKP isolates carried a carbapenemase gene, predominantly blaNDM. Raman typing revealed three major clusters among 48 Raman types identified, whereas MLVA distinguished six major clusters among a total of 30 different genotypes. CONCLUSIONS: NDM-producing CNKP are introduced into these ICUs and some strains expand clonally among patients and the environment, resulting in endemic CNKP. CNKP acquisition was associated with prolonged ICU stay and may affect ICU survival. TRIAL REGISTRATION: The study was registered at Netherlands Trial Register http://www.trialregister.nl. Candidate number: 23527, NTR number: NTR5541, NL number: NL5425 (https://www.trialregister.nl/trial/5424), Retrospectively registered: NTR: 22 December 2015.
Subject(s)
Bacterial Proteins/metabolism , Carbapenems/pharmacology , Cross Infection/epidemiology , Klebsiella Infections/epidemiology , Klebsiella pneumoniae/isolation & purification , beta-Lactamases/metabolism , Adult , Cross Infection/microbiology , Female , Humans , Indonesia/epidemiology , Intensive Care Units , Klebsiella Infections/microbiology , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/metabolism , Length of Stay , Male , Microbial Sensitivity Tests , Middle Aged , Pharynx/microbiology , Prospective Studies , Rectum/microbiologyABSTRACT
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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BackgroundSurveillance of healthcare-associated infections (HAI) is the basis of each infection control programme and, in case of acute care hospitals, should ideally include all hospital wards, medical specialties as well as all types of HAI. Traditional surveillance is labour intensive and electronically assisted surveillance systems (EASS) hold the promise to increase efficiency.ObjectivesTo give insight in the performance characteristics of different approaches to EASS and the quality of the studies designed to evaluate them.MethodsIn this systematic review, online databases were searched and studies that compared an EASS with a traditional surveillance method were included. Two different indicators were extracted from each study, one regarding the quality of design (including reporting efficiency) and one based on the performance (e.g. specificity and sensitivity) of the EASS presented.ResultsA total of 78 studies were included. The majority of EASS (n = 72) consisted of an algorithm-based selection step followed by confirmatory assessment. The algorithms used different sets of variables. Only a minority (n = 7) of EASS were hospital-wide and designed to detect all types of HAI. Sensitivity of EASS was generally high (> 0.8), but specificity varied (0.37-1). Less than 20% (n = 14) of the studies presented data on the efficiency gains achieved.ConclusionsElectronically assisted surveillance of HAI has yet to reach a mature stage and to be used routinely in healthcare settings. We recommend that future studies on the development and implementation of EASS of HAI focus on thorough validation, reproducibility, standardised datasets and detailed information on efficiency.
Subject(s)
Cross Infection/diagnosis , Delivery of Health Care/standards , Infection Control , Population Surveillance/methods , Algorithms , Cross Infection/prevention & control , Hospitals , Humans , Reproducibility of ResultsABSTRACT
BACKGROUND: We investigated prevalence and predictive factors for ESBL-E carriage in a population of mostly travellers prior to their travel (n = 2216). In addition, we examined ESBL genotype before travel and compared these to returning travellers. METHOD: A questionnaire and faecal sample were collected before travel, and a second faecal sample was collected immediately after travel. Faecal samples were analysed for ESBL-E, with genotypic characterization by PCR and sequencing. Risk factors for ESBL-E carriage prior to travel were identified by logistic regression analyses. RESULTS: Before travel, 136 participants (6.1%) were colonized with ESBL-E. Antibiotic use in the past three months (ORadjusted 2.57; 95% CI 1.59-4.16) and travel outside of Europe in the past year (1.92, 1.28-2.87) were risk factors for ESBL-E colonisation prior to travel. Travel outside of Europe carried the largest attributable risk (39.8%). Prior to travel 31.3% (40/128) of participants carried blaCTX-M 15 and 21.9% (28/128) blaCTX-M 14/18. In returning travellers 633 acquired ESBL-E of who 53.4% (338/633) acquired blaCTX-M 15 and 17.7% (112/633) blaCTX-M 14/18. CONCLUSION: In our population of Dutch travellers we found a pre-travel ESBL-E prevalence of 6.1%. Prior to travel, previous antibiotic use and travel outside of Europe were the strongest independent predictors for ESBL-E carriage, with travel outside of Europe carrying the largest attributable risk. Our molecular results suggest ESBL genes found in our study population prior to travel were in large part travel related.
Subject(s)
Carrier State/microbiology , Enterobacteriaceae Infections/epidemiology , Travel-Related Illness , Anti-Bacterial Agents/therapeutic use , Cross-Sectional Studies , Enterobacteriaceae/genetics , Enterobacteriaceae/isolation & purification , Enterobacteriaceae Infections/genetics , Feces/microbiology , Genotype , Humans , Netherlands/epidemiology , Prevalence , Risk Factors , Surveys and QuestionnairesABSTRACT
Infection control effectiveness evaluations require detailed epidemiological and microbiological data. We analyzed the genomic profiles of carbapenem-nonsusceptible Pseudomonas aeruginosa (CNPA) strains collected from two intensive care units (ICUs) in the national referral hospital in Jakarta, Indonesia, where a multifaceted infection control intervention was applied. We used clinical data combined with whole-genome sequencing (WGS) of systematically collected CNPA to infer the transmission dynamics of CNPA strains and to characterize their resistome. We found that the number of CNPA transmissions and acquisitions by patients was highly variable over time but that, overall, the rates were not significantly reduced by the intervention. Environmental sources were involved in these transmissions and acquisitions. Four high-risk international CNPA clones (ST235, ST823, ST357, and ST446) dominated, but the distribution of these clones changed significantly after the intervention was implemented. Using resistome analysis, carbapenem resistance was explained by the presence of various carbapenemase-encoding genes (blaGES-5, blaVIM-2-8, and blaIMP-1-7-43) and by mutations within the porin OprD. Our results reveal for the first time the dynamics of P. aeruginosa antimicrobial resistance (AMR) profiles in Indonesia and additionally show the utility of WGS in combination with clinical data to evaluate the impact of an infection control intervention. (This study has been registered at www.trialregister.nl under registration no. NTR5541).IMPORTANCE In low-to-middle-income countries such as Indonesia, work in intensive care units (ICUs) can be hampered by lack of resources. Conducting large epidemiological studies in such settings using genomic tools is rather challenging. Still, we were able to systematically study the transmissions of carbapenem-nonsusceptible strains of P. aeruginosa (CNPA) within and between ICUs, before and after an infection control intervention. Our data show the importance of the broad dissemination of the internationally recognized CNPA clones, the relevance of environmental reservoirs, and the mixed effects of the implemented intervention; it led to a profound change in the clonal make-up of CNPA, but it did not reduce the patients' risk of CNPA acquisitions. Thus, CNPA epidemiology in Indonesian ICUs is part of a global expansion of multiple CNPA clones that remains difficult to control by infection prevention measures.
Subject(s)
Anti-Bacterial Agents/pharmacology , Carbapenems/pharmacology , Drug Resistance, Neoplasm , Intensive Care Units , Pseudomonas Infections/epidemiology , Pseudomonas Infections/microbiology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/genetics , Humans , Indonesia/epidemiology , Infection Control , Microbial Sensitivity Tests , Pseudomonas Infections/prevention & control , Pseudomonas aeruginosa/classification , ROC CurveABSTRACT
The aim of this study was to describe the epidemiology and clinical impact of carbapenem-non-susceptible Pseudomonas aeruginosa (CNPA) in intensive care units (ICUs) of the national referral hospital of Indonesia. Adult patients admitted to ICUs were prospectively included. Pseudomonas aeruginosa were from clinical cultures and systematic screening. Environmental niches and healthcare workers (HCWs) were also screened. Susceptibility was determined phenotypically and the presence of carbapenemase genes was determined by PCR. Multiple loci variable-number tandem repeat analysis (MLVA) and multilocus sequence typing (MLST) were used for genotyping. Of the patients included in the study, 17/412 (4.1%) carried CNPA on admission and 34/395 (8.6%) became positive during their ICU stay. The acquisition rate was 18/1000 patient-days at risk. Of 16 environmental isolates, 12 (75.0%) were CNPA. HCWs screened negative. Acquisition of CNPA was associated with longer ICU stay (adjusted hazard ratioâ¯=â¯1.89, 99% confidence interval 1.12-3.13). Mortality was >40% among patients with CNPA versus <30% among those without CNPA (Pâ¯=â¯0.019). Moreover, 83/119 (69.7%) CNPA carried either blaVIM (nâ¯=â¯36), blaIMP (nâ¯=â¯23) or blaGES-5 (nâ¯=â¯24). Four sequence types (STs) dominated (ST235, ST823, ST446 and ST357). Five major MLVA clusters were distinguished, two belonging to ST235 and the other three to ST823, ST446 and ST357. CNPA are introduced into these ICUs and some strains expand clonally among patients and the environment, creating endemic CNPA. VIM-, IMP- and GES-5 genes are prevalent. CNPA acquisition was associated with prolonged ICU stay and may affect ICU survival.
Subject(s)
Anti-Bacterial Agents/therapeutic use , Pseudomonas Infections/drug therapy , Pseudomonas Infections/epidemiology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/genetics , Adult , Bacterial Proteins/genetics , Carbapenems/therapeutic use , DNA, Bacterial/genetics , Female , Humans , Indonesia/epidemiology , Infection Control/methods , Intensive Care Units/statistics & numerical data , Male , Microbial Sensitivity Tests , Middle Aged , Multilocus Sequence Typing , Prospective Studies , Pseudomonas aeruginosa/isolation & purification , beta-Lactamases/geneticsABSTRACT
Background: Hand hygiene (HH) is considered to be the single most effective measure in preventing healthcare-associated infections. However, HH compliance rates among nurses and doctors in hospitals are often very low. Few studies have addressed HH compliance in Indonesia, performed interventions to increase HH compliance, and none have had long-term follow-up. We, therefore, addressed this issue by performing long-term follow-up after a multifaceted intervention in the intensive care unit (ICU) setting. Methods: This was an observational, prospective, before-and-after intervention study (May-September 2014, February-April 2017). We measured HH knowledge and HH compliance before (at baseline) and directly after a multifaceted improvement program (post-intervention) and performed a re-evaluation three years later. The multifaceted improvement program included education, feedback, reminders, interviews and the use of role models. The study involved nurses and physicians working in two ICUs of the Dr. Cipto Mangunkusumo Hospital in Jakarta. Results: A total of 97 at baseline, and 72 at post-intervention HH knowledge questionnaires were completed. There was a statistically significant improvement in the median overall HH knowledge score at post-intervention (from 15 to 22, p < 0.001). There was no significant difference between the two ICUs. The overall HH compliance was 27% at baseline and significantly improved to 77% post-intervention (p < 0.001). For all five HH moments, the compliance of nurses and physicians separately improved significantly from the baseline phase to the post-intervention phase (p < 0.001), except for 'moment 3' (after body fluid exposure), for which baseline rates were already high. Most of the compliance rates were significantly lower in both groups of healthcare workers upon follow-up three years later. Overall, the HH compliance of the nurses was significantly better than the physicians' compliance (p = 0.005). Conclusions: Our multifaceted improvement program, for nurses and physicians of the ICUs in the largest hospital of Indonesia, resulted in a significant improvement of the HH knowledge and HH compliance, but HH compliance levels waned over time after the intervention, indicating a need for continued monitoring and repeated interventions. Trial registration: The study was registered at www.trialregister.nl (No: 5541). Candidate number: 23527, NTR number: NTR5541, Date registered NTR: 22-DECEMBER-2015.
Subject(s)
Cross Infection/prevention & control , Guideline Adherence/statistics & numerical data , Hand Hygiene/methods , Intensive Care Units/statistics & numerical data , Personnel, Hospital/education , Referral and Consultation , Follow-Up Studies , Guideline Adherence/standards , Humans , Indonesia , Nurses , Personnel, Hospital/psychology , Physicians , Prospective StudiesABSTRACT
BackgroundSurveillance of hospital-acquired infections (HAI) often relies on point prevalence surveys (PPS) to detect major deviations in the occurrence of HAI, supplemented with incidence measurements when more detailed information is needed. In a 1,320-bed university medical centre in the Netherlands, we evaluated an electronically assisted surveillance system based on frequently performed computer-assisted PPS (CAPPS).AimThe primary goals were to evaluate the performance of this method to detect trends and to determine how adjustments in the frequency with which the CAPPS are performed would affect this performance. A secondary goal was to evaluate the performance of the algorithm (nosocomial infection index (Nii)) used.MethodsWe analysed the data of 77 hospital-wide PPS, performed over a 2-year period (2013 and 2014) and including 25,056 patients.ResultsSix trends with statistical significance were detected. The probability to detect such trends rapidly decreased when PPS are performed at a lower frequency. The Nii and its dynamics strongly correlated with the presence of HAI.ConclusionPerforming computer-assisted, high frequency hospital-wide PPS, is a feasible method that will detect even subtle changes in HAI prevalence over time.
Subject(s)
Bacteremia/microbiology , Cross Infection/epidemiology , Tertiary Care Centers/statistics & numerical data , Urinary Tract Infections/microbiology , Algorithms , Bacteremia/epidemiology , Cross Infection/microbiology , Epidemiological Monitoring , Humans , Incidence , Length of Stay , Netherlands/epidemiology , Prevalence , Respiratory Tract Infections/epidemiology , Respiratory Tract Infections/microbiology , Risk Factors , Surgical Wound Infection/epidemiology , Surgical Wound Infection/microbiology , Surveys and Questionnaires , Urinary Tract Infections/epidemiologyABSTRACT
BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is endemic in healthcare settings in Indonesia. AIM: To evaluate the effect of a bundle of preventive measures on the transmission and acquisition of MRSA in a surgical ward of a resource-limited hospital in Indonesia. METHODS: The study consisted of a pre-intervention (7 months), intervention (2 months), and post-intervention phase (5 months) and included screening for MRSA among eligible patients, healthcare workers (HCWs), and the hospital environment. In the intervention phase, a bundle of preventive actions was introduced, comprising: a hand hygiene educational program, cohorting of MRSA-positive patients, decolonization therapy for all MRSA-positive patients and HCWs, and cleaning and disinfection of the ward's innate environment. Hand hygiene compliance was assessed throughout the study period. The primary outcome was the acquisition rate of MRSA among patients per 1,000 patient-days at risk. Clonality of MRSA isolates was determined by Raman spectroscopy and multilocus sequence typing. FINDINGS: In total, 1,120 patients were included. Hand hygiene compliance rate rose from 15% pre-intervention to 65% post-intervention (P<0.001). The MRSA acquisition decreased from 9/1,000 patient-days at risk pre-intervention to 3/1,000 patient-days at risk post-intervention, but this difference did not reach statistical significance (P=0.08). Raman type 9 which belonged to ST239 was the single dominant MRSA clone. CONCLUSION: The introduction of a bundle of preventive measures may reduce MRSA transmission and acquisition among surgery patients in a resource-limited hospital in Indonesia, but additional efforts are needed.
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Our human model of nasal colonization and eradication of S. aureus is limited by safety issues. As rhesus macaques are closely related to humans and natural hosts for S. aureus, we developed an experimental decolonization and inoculation protocol in these animals. Animals were screened for nasal carriage of S. aureus and 20 carriers were selected. Decolonization was attempted using nasal mupirocin (10 animals) or mupirocin plus trimethoprim/sulfadiazine intramuscularly (10 animals) both once daily for 5 days, and checked by follow-up cultures for 10 weeks. Intranasal inoculation was performed with S. aureus strain 8325-4 in culture-negative animals. 11/20 animals, of which 5 received mupirocin and 6 the combination treatment, became culture-negative for S. aureus for 10 weeks and these 11 animals were subsequently inoculated. Swabs were taken once a week for 5 weeks to test for the presence of the inoculated strain. In 3 animals, strain 8325-4 was cultured from the nose 1 week after inoculation, indicating short-term survival of this strain only, a finding similar to that previously found in our human model. These data demonstrate that rhesus macaques may constitute a relevant animal model to perform S. aureus eradication and inoculation studies with relatively limited invasive handling of the animals.
Subject(s)
Anti-Bacterial Agents/administration & dosage , Carrier State/drug therapy , Macaca mulatta/microbiology , Mupirocin/administration & dosage , Staphylococcal Infections/drug therapy , Administration, Intranasal , Animals , Anti-Bacterial Agents/therapeutic use , Carrier State/microbiology , Disease Models, Animal , Drug Combinations , Female , Male , Mupirocin/therapeutic use , Nose/microbiology , Staphylococcus aureus , Sulfadiazine , TrimethoprimABSTRACT
The fibronectin-binding protein A (FnBPA) is a cell surface-associated protein of Staphylococcus aureus which mediates adherence to the host extracellular matrix and is important for bacterial virulence. Previously, substantial sequence diversity was found among strains in the fibrinogen-binding A domain of this protein, and 7 different isotypes were described. The effect of this sequence diversity on the human antibody response, in terms of both antibody production and antibody function, remains unclear. In this study, we identify five different FnBPA A domain isotypes based on the sequence results of 22 clinical S. aureus isolates, obtained from the same number of patients suffering from bacteremia. Using a bead-based Luminex technique, we measure the patients' total immunoglobulin G (IgG) against the 7 FnBPA isotypes at the onset and during the time course of bacteremia (median of 10 serum samples per patient over a median of 35 days). A significant increase in IgG against the FnBPA A domain, including the isotype carried by the infecting strain, is observed in only three out of 22 patients (14%) after the onset of bacteremia. Using a Luminex-based FnBPA-fibrinogen-binding assay, we find that preincubation of recombinant FnBPA isotypes with IgG from diverse patients does not interfere with binding to fibrinogen. This observation is confirmed using an alternative Luminex-based assay and enzyme-linked immunosorbent assay (ELISA). IMPORTANCE Despite the many in vitro and murine in vivo studies involving FnBPA, the actual presence of this virulence factor during human infection is less well established. Furthermore, it is currently unknown to what extent sequence variation in such a virulence factor affects the human antibody response and the ability of antibodies to interfere with FnBPA function. This study sheds new light on these issues. First, the uniform presence of a patient's IgG against FnBPA indicates the presence and importance of this virulence factor during S. aureus pathogenesis. Second, the absence of an increase in antibody production in most patients following bacteremia indicates the complexity of S. aureus-host interactions, possibly involving immune evasion or lack of expression of FnBPA during invasive infection. Finally, we provide new insights into the inability of human antibodies to interfere with FnBPA-fibrinogen binding. These observations should be taken into account during the development of novel vaccination approaches.
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Background: Carbapenem-nonsusceptible A. baumannii-calcoaceticus complex have emerged worldwide, but the epidemiology in Indonesian hospitals has not been studied. Methods: A prospective observational study was performed on the intensive care units (ICUs) of the national referral hospital in Jakarta-Indonesia, in 2013 and 2014. All consecutive adult patients admitted and hospitalized for >48 h in ICUs were included. Basic and clinical data at admission were recorded. Carbapenem-nonsusceptible A. baumannii-calcoaceticus complex from clinical cultures and standardized screening were included. Environmental niches and healthcare workers (HCWs) were also screened. PCR was used to detect carbapenemase genes, and Raman spectroscopy as well as multilocus sequence typing (MLST) for typing. Results: Of 412 included patients, 69 (16.7%) carried carbapenem-nonsusceptible A. baumannii-calcoaceticus complex on admission, and 89 (25.9%) became positive during ICU stay. The acquisition rate was 43 per 1000 patient-days at risk. Six isolates were cultured from environment and one from a HCW. Acquisition of carbapenem-nonsusceptible A. baumannii-calcoaceticus complex was associated with longer ICU stay (median interquartile range [IQR]: 11 days [5-18], adjusted hazard ratio [aHR]: 2.56 [99% confidence interval (CI):1.76-3.70]), but not with mortality (adjusted odds ratio: 1.59 [99%CI: 0.74-3.40] at the chosen level of significance). The blaOXA-23-like gene was detected in 292/318 (91.8%) isolates, including isolates from the environment and HCW. Typing revealed five major clusters. Sequence types (ST)195, ST208, ST218, ST642 as well as new STs were found. The dominant clone consisted of isolates from patients and environment throughout the study period. Conclusions: Carbapenem-nonsusceptible A. baumannii-calcoaceticus complex are endemic in this setting. Prevention requires source control and limiting transmission of strains. Trial registration: The study was retrospectively registered at www.trialregister.nl (No:5541). Candidate number: 23,527, NTR number: NTR5541, Date registered NTR: 22nd December 2015.
Subject(s)
Acinetobacter Infections/epidemiology , Acinetobacter baumannii/genetics , Acinetobacter calcoaceticus/genetics , Carbapenems/pharmacology , Intensive Care Units , Molecular Epidemiology , Referral and Consultation , Acinetobacter Infections/microbiology , Acinetobacter baumannii/classification , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/isolation & purification , Acinetobacter calcoaceticus/classification , Acinetobacter calcoaceticus/drug effects , Acinetobacter calcoaceticus/isolation & purification , Adult , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/genetics , DNA, Bacterial , Drug Resistance, Bacterial/genetics , Female , Health Personnel , Humans , Indonesia/epidemiology , Male , Microbial Sensitivity Tests , Middle Aged , Multilocus Sequence Typing/methods , Polymerase Chain Reaction/methods , Prevalence , Prospective Studies , Retrospective Studies , beta-Lactamases/geneticsABSTRACT
Host chitinases, chitotriosidase and acidic mammalian chitinase (AMCase), improved the antifungal activity of caspofungin (CAS) against Aspergillus fumigatus in vitro These chitinases are not constitutively expressed in the lung. Here, we investigated whether chitosan derivatives were able to induce chitinase activity in the lungs of neutropenic rats and, if so, whether these chitinases were able to prolong survival of rats with invasive pulmonary aspergillosis (IPA) or of rats with IPA and treated with CAS. An oligosaccharide-lactate chitosan (OLC) derivative was instilled in the left lung of neutropenic rats to induce chitotriosidase and AMCase activities. Rats instilled with OLC or with phosphate-buffered saline (PBS) were subsequently infected with A. fumigatus and then treated with suboptimal doses of CAS. Survival, histopathology, and galactomannan indexes were determined. Instillation of OLC resulted in chitotriosidase and AMCase activities. However, instillation of OLC did not prolong rat survival when rats were subsequently challenged with A. fumigatus In 5 of 7 rats instilled with OLC, the fungal foci in the lungs were smaller than those in rats instilled with PBS. Instillation of OLC did not significantly enhance the survival of neutropenic rats challenged with A. fumigatus and treated with a suboptimal dosage of CAS. Chitotriosidase and AMCase activities can be induced with OLC, but the presence of active chitinases in the lung did not prevent the development of IPA or significantly enhance the therapeutic outcome of CAS treatment.
Subject(s)
Aspergillus fumigatus/metabolism , Caspofungin/pharmacology , Chitinases/metabolism , Invasive Pulmonary Aspergillosis/drug therapy , Neutropenia/complications , Animals , Antifungal Agents/pharmacology , Aspergillus fumigatus/drug effects , Aspergillus fumigatus/pathogenicity , Chitosan/chemistry , Chitosan/pharmacology , Disease Models, Animal , Female , Invasive Pulmonary Aspergillosis/metabolism , Invasive Pulmonary Aspergillosis/prevention & control , Lung/drug effects , Lung/enzymology , Microbial Sensitivity Tests , Molecular Weight , Neutropenia/microbiology , RatsABSTRACT
OBJECTIVES: To define the role of Staphylococcus aureus in community settings among patients with skin and soft tissue infections (SSTI) in Indonesia. METHODS: Staphylococcus aureus were cultured from anterior nares, throat and wounds of 567 ambulatory patients presenting with SSTI. The mecA gene and genes encoding Panton-Valentine leukocidin (PVL; lukF-PV and lukS-PV) and exfoliative toxin (ET; eta and etb) were determined by PCR. Clonal relatedness among methicillin-resistant S. aureus (MRSA) and PVL-positive S. aureus was analysed using multilocus variable-number tandem-repeat analysis (MLVA) typing, and multilocus sequence typing (MLST) for a subset of isolates. Staphylococcal cassette chromosome mec (SCCmec) was determined for all MRSA isolates. Moreover, determinants for S. aureus SSTI, and PVL/ET-positive vs PVL/ET-negative S. aureus were assessed. RESULTS: Staphylococcus aureus were isolated from SSTI wounds of 257 (45.3%) patients, eight (3.1%) of these were MRSA. Genes encoding PVL and ETs were detected in 21.8% and 17.5% of methicillin-susceptible S. aureus (MSSA), respectively. PVL-positive MRSA was not detected. Nasopharyngeal S. aureus carriage was an independent determinant for S. aureus SSTI (odds ratio [OR] 1.8). Primary skin infection (OR 5.4) and previous antibiotic therapy (OR 3.5) were associated with PVL-positive MSSA. Primary skin infection (OR 2.2) was the only factor associated with ET-positive MSSA. MLVA typing revealed two more prevalent MSSA clusters. One ST1-MRSA-SCCmec type IV isolate and a cluster of ST239-MRSA-SCCmec type III were found. CONCLUSIONS: Community-acquired SSTI in Indonesia was frequently caused by PVL-positive MSSA, and the hospital-associated ST239-MRSA may have spread from the hospital into the community.
Subject(s)
Bacterial Proteins/isolation & purification , Community-Acquired Infections/microbiology , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Penicillin-Binding Proteins/isolation & purification , Soft Tissue Infections/microbiology , Staphylococcal Infections/microbiology , Adult , Community-Acquired Infections/epidemiology , Community-Acquired Infections/genetics , Humans , Indonesia/epidemiology , Male , Methicillin-Resistant Staphylococcus aureus/genetics , Prevalence , Soft Tissue Infections/epidemiology , Soft Tissue Infections/genetics , Staphylococcal Infections/epidemiology , Staphylococcal Infections/genetics , Staphylococcus aureus/genetics , Staphylococcus aureus/isolation & purification , Young AdultABSTRACT
To understand the dynamics behind the worldwide spread of the mcr-1 gene, we determined the population structure of Escherichia coli and of mobile genetic elements (MGEs) carrying the mcr-1 gene. After a systematic review of the literature we included 65 E. coli whole genome sequences (WGS), adding 6 recently sequenced travel related isolates, and 312 MLST profiles. We included 219 MGEs described in 7 Enterobacteriaceae species isolated from human, animal and environmental samples. Despite a high overall diversity, 2 lineages were observed in the E. coli population that may function as reservoirs of the mcr-1 gene, the largest of which was linked to ST10, a sequence type known for its ubiquity in human faecal samples and in food samples. No genotypic clustering by geographical origin or isolation source was observed. Amongst a total of 13 plasmid incompatibility types, the IncI2, IncX4 and IncHI2 plasmids accounted for more than 90% of MGEs carrying the mcr-1 gene. We observed significant geographical clustering with regional spread of IncHI2 plasmids in Europe and IncI2 in Asia. These findings point towards promiscuous spread of the mcr-1 gene by efficient horizontal gene transfer dominated by a limited number of plasmid incompatibility types.