Ceftazidime-avibactam resistance and restoration of carbapenem susceptibility in KPC-producing Klebsiella pneumoniae infections: A case series.

OBJECTIVES: Since the introduction of the ß-lactam/ß-lactamase inhibitor ceftazidime-avibactam (CZA), rapid evolution of resistance has been reported in different KPC-producing Klebsiella pneumoniae isolates. In this multicenter retrospective study, we describe the emergence of CZA resistance and evaluate the mutations that might be responsible for the restoration of carbapenem susceptibility. METHODS: During a study period of 18 months, KPC-producing K. pneumoniae isolates of five hospitalized patients were collected with phenotypic development of CZA resistance. RESULTS: In vitro restoration of carbapenem susceptibility during treatment was observed in 3 isolates. Whole genome sequencing of these isolates showed a D179Y mutation in the KPC gene of 2 variants and a KPC-2 with a Δ242-GT-243 deletion (KPC-14). Two KPC-3 variants showed CZA resistance with sustained carbapenemase activity without genomic adaptations in the KPC gene. CONCLUSIONS: This study confirms the emergence of CZA resistance in KPC K. pneumoniae. The role of carbapenems in treating patients with these variants is unclear and combination therapies warrant further investigation.

RESIST-5 O.O.K.N.V. and NG-Test Carba 5 assays for the rapid detection of carbapenemase-producing Enterobacterales from positive blood cultures: a comparative study.

We prospectively compared the performance of RESIST-5 O.O.K.N.V. and NG-Test Carba 5 assays directly from blood cultures spiked with 130 characterized Enterobacterales isolates. Overall, both assays yielded 100% sensitivity to detect KPC-type carbapenemases and OXA-48-like carbapenemases. Both assays failed to detect KPC-31 and KPC-33, D179Y point mutation variants of KPC-3 and KPC-2, that are deprived of carbapenemase activity and confer resistance to ceftazidime-avibactam. On blood culture bacterial pellets, NDM- and VIM-type carbapenemases were detected in 50.0% and 52.2%, respectively, by RESIST-5 O.O.K.N.V. vs 100% by NG-Test Carba 5. The sensitivity of RESIST-5 O.O.K.N.V. improved to 100% and 95.6%, respectively, by performing the assay on 4-h early subculture.

Physiotherapy assessment for female urinary incontinence.

INTRODUCTION AND HYPOTHESIS: As noted in the 6th International Consultation on Incontinence (ICI) chapter "Initial Management of Urinary Incontinence in Women" recommendations call for including physiotherapy as a first-line therapy. METHODS: Building on this, checking available scientific evidence and using the International Classification of Functioning, Disabilities and Health, the following represents a holistic physiotherapist approach for initial evaluation of the health problem of urinary incontinence. RESULTS: This paper proposes a teaching module for every relevant health care professional dealing with the assessment of adult female urinary incontinence, focusing on optimal patient selection and appropriate treatment choice. CONCLUSION: The assessment stage involves the explicit decision as to whether "physiotherapy" is the treatment indicated for the patient, based on the findings of the physiotherapy assessment and supplemented by any medical information that accompanied the referral and evaluation.

Carriage of antibiotic-resistant Gram-negative bacteria after discontinuation of selective decontamination of the digestive tract (SDD) or selective oropharyngeal decontamination (SOD).

BACKGROUND: Selective decontamination of the digestive tract (SDD) and selective oropharyngeal decontamination (SOD) reduce colonization with antibiotic-resistant Gram-negative bacteria (ARGNB), incidence of nosocomial infections and improve survival in ICU patients. The effect on bacterial gut colonization might be caused by growth suppression by antibiotics during SDD/SOD. We investigated intestinal colonization with ARGNB after discharge from ICU and discontinuation of SDD or SOD. METHODS: We performed a prospective, observational follow-up study in regular hospital wards of three teaching hospitals in the Netherlands in patients discharged from the ICU, who were participating in a cluster randomized trial comparing SDD with SOD. We determined rectal carriage with ARGNB at ICU discharge (time (T) = 0) and 3, 6 and 10 days after discharge. The primary endpoint was time to first colonization with ARGNB that was not present at T = 0. Bacteria that are intrinsically resistant to antibiotics were not included in the primary analysis, but were included in post-hoc analysis. RESULTS: Of 1370 patients screened for inclusion, 996 patients had samples at T = 0 (507 after SDD and 489 after SOD). At ICU discharge, the prevalence of intestinal carriage with any ARGNB was 22/507 (4.3%) after SDD and 87/489 (17.8%) after SOD (p < 0.0001): 426 (SDD) and 409 (SOD) patients had at least one follow-up sample for analysis. The hazard rate for acquiring carriage of ARGNB after discontinuation of SDD, compared to SOD, in the ICU was 0.61 (95% CI 0.40-0.91, p = 0.02), and cumulative risks of acquisition of at least one ARGNB until day 10 were 13% (SDD) and 18% (SOD). At day 10 after ICU discharge, the prevalence of intestinal carriage with ARGNB was 11.3% (26/230 patients) after SDD and 12.5% (28/224 patients) after SOD (p = 0.7). In post-hoc analysis of all ARGNB, including intrinsically resistant bacteria, colonization at ICU discharge was lower after SDD (4.9 vs. 22.3%, p < 0.0001), but acquisition rates after ICU discharge were similar in both groups. CONCLUSIONS: Intestinal carriage at ICU discharge and the acquisition rate of ARGNB after ICU discharge are lower after SDD than after SOD. The prevalence of intestinal carriage with ARGNB at 10 days after ICU discharge was comparable in both groups, suggesting rapid clearance of ARGNB from the gut after ICU discharge. TRIAL REGISTRATION: Netherlands Trial Registry, NTR3311 . Registered on 28 february 2012.

An integrated approach to control a prolonged outbreak of multidrug-resistant Pseudomonas aeruginosa in an intensive care unit.

In this paper we aim to provide insight into the complexity of outbreak management in an intensive care unit (ICU) setting. In October 2010 four patients on the ICU of our tertiary care centre were colonized or infected with a multidrug-resistant strain of Pseudomonas aeruginosa (MDR-PA). An outbreak investigation was carried out and infection control measures were taken in an attempt to identify a potential source and stop transmission. The outbreak investigation included descriptive epidemiology, comprising retrospective case finding by reviewing the laboratory information system back to 2004 and prospective case finding by patient screening for MDR-PA. Furthermore, microbiological analysis, environmental screening and a case-control study were carried out. Infection control measures consisted of re-education of healthcare personnel on basic hygiene measures, auditing of hygiene procedures used in daily practice by infection control practitioners, and stepwise up-regulation of isolation measures. From February 2009 to January 2012, 44 patients on our ICU were found to be MDR-PA positive. MDR-PA isolates of the 44 patients showed two distinct AFLP patterns, with homology within each of the AFLP clusters of more than 93%. The VIM metallo-ß-lactamase gene was detected in 20 of 21 tested isolates. A descriptive epidemiology investigation identified the rooms with the highest numbers of MDR-PA positive patients. The case-control study showed three factors to be independently associated with MDR-PA positivity: admission to ICU subunit 1 (OR, 6.1; 95% CI, 1.7, 22), surgery prior to or during admission (OR, 5.7; 95% CI, 1.6, 20) and being warmed-up with the warm-air blanket (OR, 3.6; 95% CI, 1.2, 11). After three environmental screening rounds, with sampling of sinks, furniture and devices in the ICU, without revealing a clear common source, a fourth environmental investigation included culturing of faucet aerators. Two faucets were found to be positive for MDR-PA and were replaced. The occurrence of new cases decreased with the strengthening of infection control measures and declined further with the removal of the common source. With this integrated approach a prolonged outbreak of P. aeruginosa was controlled. Contaminated faucet aerators on the ICU probably served as a persisting source, while interpatient transmission by medical staff was a likely way of spread. Seven months after the last case (January 2012) and 3 months after cessation of extended isolation measures (May 2012), single cases started to occur on the ICU, with a total of seven patients in the past year. No common source has yet been found.

Characterization of fluoroquinolone and cephalosporin resistance mechanisms in Enterobacteriaceae isolated in a Dutch teaching hospital reveals the presence of an Escherichia coli ST131 clone with a specific mutation in parE.

OBJECTIVES: To characterize the mechanisms of fluoroquinolone and cephalosporin resistance in Enterobacteriaceae from a Dutch teaching hospital in 2008. METHODS: We sequenced gyrA, gyrB, parC and parE. The presence of plasmid-encoded genes qnrA, qnrB, qnrS, aac(6')-Ib, qepA, bla(TEM), bla(SHV,) bla(OXA), bla(CTX-M) and bla(AmpC) was studied by PCR. Escherichia coli isolates were further characterized by AFLP and multilocus sequence typing (MLST). RESULTS: In total, 49 E. coli, 16 Klebsiella pneumoniae and 3 Enterobacter cloacae isolates were investigated. Mutations in gyrA were found in all E. coli isolates. Forty-five (92%) E. coli isolates carried at least one point mutation in parC. Most E. coli isolates (59%) also carried mutations in parE, of which I529L was the most prevalent. I529L was unequivocally associated with E. coli sequence type (ST) 131. This single-nucleotide polymorphism (SNP) was later also found in eight out of nine ST131 strains from another collection. Twenty-nine E. coli isolates carried extended-spectrum ß-lactamase (ESBL) genes, predominantly bla(CTX-M-15). In E. coli, aac(6')-Ib-cr was the predominant plasmid-mediated resistance mechanism, whereas in K. pneumoniae qnr genes were found mostly. In K. pneumoniae isolates, qnr and aac(6')-Ib-cr co-occurred with ESBL genes (n = 13; bla(CTX-M) and bla(SHV)) and/or bla(AmpC) (n = 3; bla(DHA-1)). CONCLUSIONS: E. coli ST131 was the predominant clone, which accumulated a high number of chromosomal mutations. The I529L SNP in parE was a signature of most, but not all, ST131 strains. In contrast to E. coli, fluoroquinolone resistance mechanisms were predominantly plasmid-encoded in K. pneumoniae.

Endemic and epidemic acinetobacter species in a university hospital: an 8-year survey.

The prevalence of the currently known Acinetobacter species and related trends of antimicrobial resistance in a Dutch university hospital were studied. Between 1999 and 2006, Acinetobacter isolates from clinical samples were collected prospectively. Isolates were analyzed by amplified fragment length polymorphism fingerprinting. For species identification, a profile similarity cutoff level of 50% was used, and for strain identification, a cutoff level of 90% was used. Susceptibility for antimicrobial agents was tested by disk diffusion by following the CLSI guideline. The incidences of Acinetobacter isolates ranged from 1.7 to 3.7 per 10,000 patients per year, without a trend of increase, during the study years. Twenty different species were distinguished. Acinetobacter baumannii (27%) and Acinetobacter genomic species (gen. sp.) 3 (26%) were the most prevalent. Other species seen relatively frequently were Acinetobacter lwoffii (11%), Acinetobacter ursingii (4%), Acinetobacter johnsonii (4%), and Acinetobacter junii (3%). One large cluster of A. baumannii, involving 31 patients, and 16 smaller clusters of various species, involving in total 39 patients, with at most 5 patients in 1 cluster, occurred. Overall, 37% of the A. baumannii isolates were fully susceptible to the tested antibiotics. There was a borderline significant (P = 0.059) trend of decreasing susceptibility. A. baumannii was the Acinetobacter species causing the largest burden of multiple-antibiotic resistance and transmissions in the hospital.

Do maggots have an influence on bacterial growth? A study on the susceptibility of strains of six different bacterial species to maggots of Lucilia sericata and their excretions/secretions.

PURPOSE: The maggots of Lucilia sericata are successfully used as a treatment for infected wounds. Many articles are published about possible direct antibacterial properties of maggots and their excretions/secretions (ES), but with different results. The present study reinvestigates the susceptibility of six bacterial strains to maggots and their ES. METHODS: Live maggots were added to a bacterial suspension. After incubation for 16 h, the bacterial growth in this suspension was compared with the growth in a suspension without maggots. We tested Instar-1 and Instar-3 maggots and compared nutrient broths. A turbidimetric assay investigated the antibacterial activity of ES. Finally, we compared the bacterial growth of Gram-positive and Gram-negative bacteria. RESULTS: The test with live maggots showed an increase of bacterial growth. Instar-1 maggots stimulated more bacterial growth than Instar-3 maggots, as well as the use of a more nutritious broth. The turbidimetric assay showed no inhibition of bacterial growth. For all bacteria, except Pseudomonas aeruginosa, an increase in bacterial growth was shown. CONCLUSION: There is no direct antibacterial effect of maggots and/or ES in vitro, however in clinical observations maggot therapy is successful. More research is needed to focus on possible indirect antibacterial activity, such as an immune-related effect.

Decontamination of the digestive tract and oropharynx in ICU patients.

BACKGROUND: Selective digestive tract decontamination (SDD) and selective oropharyngeal decontamination (SOD) are infection-prevention measures used in the treatment of some patients in intensive care, but reported effects on patient outcome are conflicting. METHODS: We evaluated the effectiveness of SDD and SOD in a crossover study using cluster randomization in 13 intensive care units (ICUs), all in The Netherlands. Patients with an expected duration of intubation of more than 48 hours or an expected ICU stay of more than 72 hours were eligible. In each ICU, three regimens (SDD, SOD, and standard care) were applied in random order over the course of 6 months. Mortality at day 28 was the primary end point. SDD consisted of 4 days of intravenous cefotaxime and topical application of tobramycin, colistin, and amphotericin B in the oropharynx and stomach. SOD consisted of oropharyngeal application only of the same antibiotics. Monthly point-prevalence studies were performed to analyze antibiotic resistance. RESULTS: A total of 5939 patients were enrolled in the study, with 1990 assigned to standard care, 1904 to SOD, and 2045 to SDD; crude mortality in the groups at day 28 was 27.5%, 26.6%, and 26.9%, respectively. In a random-effects logistic-regression model with age, sex, Acute Physiology and Chronic Health Evaluation (APACHE II) score, intubation status, and medical specialty used as covariates, odds ratios for death at day 28 in the SOD and SDD groups, as compared with the standard-care group, were 0.86 (95% confidence interval [CI], 0.74 to 0.99) and 0.83 (95% CI, 0.72 to 0.97), respectively. CONCLUSIONS: In an ICU population in which the mortality rate associated with standard care was 27.5% at day 28, the rate was reduced by an estimated 3.5 percentage points with SDD and by 2.9 percentage points with SOD. (Controlled Clinical Trials number, ISRCTN35176830.)

Can Escherichia coli be used as an indicator organism for transmission events in hospitals?

Can Escherichia coli be used as an indicator organism for transmission events in hospitals? Perineal and pharyngeal swabs were obtained from patients admitted to a medical or surgical intensive care unit within 24 h of admission and then twice per week. Escherichia coli isolates were typed by random amplification of polymorphic DNA (RAPD) and amplified fragment length polymorphism (AFLP) typing. Based on the typing results, transmission rates for RAPD and AFLP typing were 8.5 and 6.6 per 100 patient-days. Requiring in addition to similarity in genotype parity in time and place for a transmission event, the incidence dropped to 3.8 (RAPD) and 1.7 (AFLP) per 100 patient-days. The two typing methods not only differed with respect to numbers of transmissions identified, but also to individuals involved in transmissions. This study identified a number of problems regarding the use of Escherichia coli as indicator organism for transmission events. The use of Escherichia coli for this purpose cannot be recommended at the moment.

[Community-acquired Staphylococcus aureus pneumonia following influenza and the choice of empirical antibiotic treatment]. / Thuis opgelopen pneumonie door Staphylococcus aureus na influenza en de keuze voor empirische antibiotische behandeling.

A 30-year-old man presented with community-acquired pneumonia (CAP), directly following influenza. Sputum Gram stain confirmed Staphylococcus aureus pneumonia. Initial empirical antimicrobial therapy did not cover S. aureus. The isolated S. aureus strain contained genes encoding exotoxins, such as Panton-Valentine leukocidin (PVL). This exotoxin is associated with high mortality and methicillin resistance, but in this patient the strain was susceptible to methicillin. The patient died. In the Netherlands the risk of methicillin resistance in PVL-positive S. aureus CAP is low but real. This should be taken into account when selecting empirical treatment, which can include the combination of flucloxacillin and rifampicin. This case report illustrates the difficulty in predicting the causative agent in CAP and highlights the usefulness of the sputum Gram stain. Moreover, clinical awareness and recognition of S. aureus CAP remains essential to the early initiation of directed therapy.

Multifactorial origin of high incidence of Serratia marcescens in a cardio-thoracic ICU: analysis of risk factors and epidemiological characteristics.

OBJECTIVE: A four-fold increase in the incidence of Serratia marcescens occurred in a cardio-thoracic ICU within a 13-month period. Clinical, epidemiological and molecular characteristics were analysed to elucidate the outbreak's origin. METHODS: Epidemiological data were analysed by mapping clustered cases; isolates were genotyped by AFLP analysis. A case-control study was performed to identify risk factors for the acquisition of S. marcescens. Data were obtained from files and electronic databases of the ICU and Department of Medical Microbiology. The adherence to hygiene protocols on the ICU was reviewed by a medical audit. RESULTS: Genotyping showed 16 distinct S. marcescens strains. Twenty-one cases and 39 controls were enrolled in the case-control study. Significant differences found by univariate analysis included the duration of surgery, APACHE-II-score on ICU admission, length of ICU stay, duration of mechanical ventilation, tube feeding and the sum of the number of days per invasive device. In a multivariate logistic regression model, the length of ICU stay and tube feeding were independent risk factors. Outbreak strains were not more frequently resistant to gentamicin, ciprofloxacin, meropenem or trimethoprim-sulfamethoxazole as compared to a reference group. Hygiene protocols, including hand washing, were insufficiently practiced by the ICU's medical staff. CONCLUSIONS: The heterogeneity of the strains points to transmission from various sources. This outbreak of S. marcescens was most probably caused by reduced hand washing and other breaks in infection prevention protocols in combination with the presence of the identified risk factors, which act by affecting the number and intensity of potential transmission events.

Dissemination of Bacillus cereus in a paediatric intensive care unit traced to insufficient disinfection of reusable ventilator air-flow sensors.

Over a two-week period in November 2006, vancomycin-resistant Bacillus cereus was isolated from respiratory samples from six ventilated paediatric intensive care unit (PICU) patients. To investigate the possibility of a common source and extent of the dissemination, all procedures related to mechanical ventilation were monitored and surveillance cultures performed. B. cereus was isolated from reusable air-flow sensors, before and after on-site disinfection with 70% alcohol. The organism was also isolated from respiratory samples from three other ventilated patients and from two ventilation grids in the ceiling of PICU, as well as from the alcohol solution itself. Using amplified fragment length polymorphism (AFLP) typing, B. cereus strains from the six PICU patients together with isolates recovered from the air-flow sensors and the alcohol solution were shown to be closely related. Isolates from the ventilation grids demonstrated different AFLP patterns to the outbreak strain. Intervening measures, including disinfection by autoclaving all reusable air-flow-guiding parts and the use of disposable non-autoclavable parts, resulted in rapid termination of the outbreak. B. cereus infections can cause significant morbidity, particularly in intensive care patients. Disinfection of all air-flow-guiding reusable parts for mechanical ventilation should be addressed with great care and should include effective autoclaving in order to eradicate spores.

Mycobacterium chelonae keratitis in a patient with Sjögren's syndrome.

PURPOSE: In this report a case of Mycobacterium chelonae keratitis in a patient without any previously described risk factors is described. The only risk factor found was a rheumatoid arthritis related Sjogren''s syndrome. METHODS: Case report. RESULTS: A 60-year-old woman was referred to the hospital with an infectious keratitis of the left eye of 3 months duration, unresponsive to empirical therapy with ofloxacin and tobramycin drops. Her medical history included a longstanding rheumatoid arthritis and a secondary ocular surface syndrome. Upon arrival the left eye showed diffuse corneal edema and centrally several large infiltrates with fluffy edges, surrounded by several smaller satellite infiltrates. The cornea was scraped for culture and grew M chelonae and sensitivity testing showed sensitivity to ciprofloxacin, clofazimine, and clarithromycin. Systemically, ciprofloxacin 750 mg and clarithromycin 500 mg twice daily were prescribed orally. Topical therapy consisted of topical erythromycin 10 mg/mL and ofloxacin 3 mg/mL every 2 hours. Treatment was continued for a total of 10 months during which the infiltrates cleared completely, but the central cornea remained scarred. CONCLUSIONS: M chelonae can be a cause of infectious keratitis in patients without known risk factors for rapidly growing mycobacterium keratitis. Especially in the case of ocular infections that show no response to regular antibacterial treatment, mycobacterial infection should be considered. Good communication between the ophthalmologist and the microbiologist is crucial for a rapid diagnosis.

Molecular typing of a suspected cluster of Nocardia farcinica infections by use of randomly amplified polymorphic DNA, pulsed-field gel electrophoresis, and amplified fragment length polymorphism analyses.

Randomly amplified polymorphic DNA (RAPD), pulsed-field gelelectrophoresis (PFGE), and amplified fragment length polymorphism (AFLP) analyses were used to investigate a possible outbreak of Nocardia farcinica. RAPD and PFGE analyses yielded irreproducible and unsatisfactory results, respectively. AFLP analysis seem to be a promising and welcome addition for molecular analysis of Nocardia isolates.

Genotypic diversity and antibiotic susceptibility of Acinetobacter baumannii isolates in a Bulgarian hospital.

A set of 18 Acinetobacter baumannii isolates, collected prospectively in a Bulgarian hospital during episodes of increased A. baumannii occurrence during 2000-2002, was investigated for genotypic diversity and antibiotic susceptibility. Four genotypes were identified by amplified fragment length polymorphism genomic fingerprinting, one of which (type 1) accounted for 13 isolates, indicating that a specific strain was predominant. The single isolate allocated to type 2 was identified to European clone I. All isolates were resistant to multiple antibiotics, but most retained susceptibility to tobramycin and colistin, and all except one were susceptible to imipenem.

Epidemiology of multiple Acinetobacter outbreaks in The Netherlands during the period 1999-2001.

An increase in the number of outbreaks of Acinetobacter infection was notified in The Netherlands during 1999-2001. The present study compared the outbreaks at the species and strain levels, and analysed the epidemiology and control measures at the different locations. For each institute, three representative isolates from three patients were identified to the species and strain levels by genotyping methods. A questionnaire investigated the impact of the outbreak, the control measures that were taken, and the possible effects of the measures. Seven outbreaks were associated with Acinetobacter baumannii (three outbreaks with a strain designated strain A, two outbreaks with a strain designated strain B, and one outbreak each with strains designated C and D). An additional outbreak was caused by genomic species 13TU, which is related closely to A. baumannii. Strains B and D were identified as European clones III and II, respectively. Except for two hospitals with outbreaks caused by strain A, there was no known epidemiological link between the participating hospitals. In all hospitals the outbreak occurred on one or several intensive care units, and spread to other departments was noted in two hospitals. The number of patients affected ranged from six to 66 over a period of 2-22 months. In most outbreaks, patients were the likely reservoir from which spread occurred. In all hospitals, a large panel of measures was required to bring the outbreak to an end. Extensive environmental sampling yielded numerous positive samples in most but not all hospitals.

[Maggot therapy for treatment of severe infections in trauma surgery: "back to the future!"]. / Maden: Ein neues Konzept in der Behandlung von Infektionen in der Traumatologie -- "Back to the Future!"

The ancient method of larval therapy for treatment of acute and chronic infections has become a revival and a new dimension with introduction of the Biobag (Vitapad). With use of this therapy trauma patients suffering infectious complications can be treated very effective, which can reduce the overall time needed for treatment and can result in diminished invalidity.

Prevalence of Acinetobacter baumannii and other Acinetobacter spp. in faecal samples from non-hospitalised individuals.

In total, 226 individuals from the community were investigated for faecal carriage of Acinetobacter spp. by broth enrichment culture, followed by growth on blood agar and/or Leeds Acinetobacter Medium (LAM). Acinetobacter baumannii was isolated on both LAM and blood agar from one of 100 specimens in the UK and one of 126 specimens in The Netherlands. The predominant species were Acinetobactor johnsonii and genomic sp. 11, which were cultured from 22 and five specimens, respectively. A. baumannii did not seem to be widespread in the faecal flora of individuals in the community.