Bacterial colonization of the respiratory tract in patients with cystic fibrosis

Cystic fibrosis (CF) is the most common single gene disorder in The Netherlands and occurs approximately once in every 3600 children born alive. The heterozygous carrier frequency has been estimated to be approximately 1 :30. The defective gene was identified in 1989 and appeared to be located on chromosome. It codes for the cystic fibrosis transmembrane conductance regulator (CFTR), which acts as a transmembrane chloride channel. The most frequent mutation of this gene is the deletion of phenylalanine at position 508 ("F508). Almost 60% of the known CF patients in The Netherlands are homozygous for the "F508 mutation. More than 700 additional CFTR mutations related to CF have been identified as oflate May 1997 by the CF Genetic Analysis Consortium. The gene defect results in significant morbidity and affects mainly the respiratory tract and the pancreas. The CF lung presents an unique environment to microbial pathogens. The combination oflow or absent chloride secretion and an increased sodium absorption results in relative dehydration of the ainvays. Consequently, the disease is characterized by the production of abnonnally viscid secretions in epithelial tissues. Mucociliary clearance of bacteria from the lungs is impaired because of the viscid, dehydrated nature of the airway epithelia. Chronic ainvay inflammation leads to excessive secretion of purulent mucus and to obstmction of the airway which in turn causes bronchiectasis, pulmonary hypertension with cor pulmonale, haemoptysis, pneumothorax and, finally, respiratory failure. The exacerbation of puhnonary infections is the major cause of morbidity and mortality in patients with CF. Aggressive early treatment of respiratory infections is a critical success factor in the treatment ofCF patients. Thirty years ago, most patients died in infancy. Nowadays, patients born in the 1990's are likely to live up to a median age of 40 years

Screening of post-mortem tissue donors for Coxiella burnetii infection after large outbreaks of Q fever in The Netherlands

BACKGROUND: After the largest outbreaks of Q fever ever recorded in history occurred in the Netherlands, concern arose that Coxiella may be transmitted via donated tissues of latent or chronically infected donors. The Dutch Health Council recently advised to screen tissue donors, donating high risk tissues, for Coxiella infection. METHODS: After validation of an enzyme immunoassay (EIA) test for IgG antibodies against phase 2 of C. burnetii for use on post-mortem samples, serum samples of 1033 consecutive Dutch post-mortem tissue donors were tested for IgG antibodies against phase 2 of C. burnetii. Confirmation of reactive results was done by immunofluorescence assay (IFA). All available tissues (corneas, heart valves, skin and bone marrow) from donors with IgG reactivity were tested for presence of Coxiella DNA by PCR. Risk factors for IgG reactivity were investigated. RESULTS: After validation of the tests for use on post-mortem samples, 50/1033 donors (4.8%) screened positive for phase 2 anti-Coxiella IgG by EIA, and 31 were confirmed by IFA (3.0%). One donor showed a serological profile compatible with chronic infection. All tested tissues (25 corneas, 6 heart valves, 4 skin and 3 bone marrow) from donors with IgG reactivity tested negative for the presence of Coxiella DNA. Except for living in a postal code area with a high number of Q fever notifications, no risk factors for IgG reactivity were found. CONCLUSIONS: The strong correlation between notifications and seroprevalence confirms that the used assays are sufficiently specific for use on post-mortem samples, although one has to be aware of differences between batches. Thus, this study provides a validated method for screening tissue donors for infection with Coxiella burnetii that can be used in future outbreaks

Methicillin-Resistant Staphylococcus aureus in a Beauty Salon, the Netherlands

An outbreak of community-associated USA300 methicillin-resistant Staphylococcus aureus occurred in a beautician and 2 of her customers. Eight other persons, who were either infected (n = 5) or colonized (n = 3), were linked to this outbreak, including a family member, a household contact, and partners of customers

Long-term serological follow-up after primary Coxiella burnetii infection in patients with vascular risk factors for chronic Q fever

We evaluated the long-term serological follow-up of patients with vascular risk factors for chronic Q fever that were previously Coxiella burnetii seropositive. C. burnetii phase I IgG titers were reevaluated in patients that gave informed consent or retrospectively collected in patients already deceased or lost to follow-up. Of 107 patients, 25 (23.4%) became seronegative, 77 (72.0%) retained a profile of past resolved Q fever infection, and five (4.7%) developed chronic Q fever. We urge clinicians to stay vigilant for chronic Q fever beyond two years after primary infection and perform serological testing based on clinical presentation

Injury Surveillance in Elite New Zealand Track Cyclists

Introduction: Injury surveillance is an essential component of elite sport. Little data is available on injury rates in track cyclists, with the majority of cycling research focussed on road cycling, and suggesting cyclists are at highest risk of overuse knee, back and neck injuries, and acute injuries involving the shoulder/clavicle, lower back and knee. Purpose: This research aims to establish the baseline incidence and prevalence of injury, and its effect on training and competition for elite New Zealand track-cyclists. Methods: All members of Cycling New Zealand’s elite track squad were invited to take part in this prospective, longitudinal study. Participants completed two baseline questionnaires detailing current and past injury status, current training volume, and other baseline characteristics. They then completed an online self-reporting injury survey every week for 52 consecutive weeks in the form of the Programme for Injury and Illness Surveillance (PILLS) tool. Injuries were classified using the OSICS-10 classification system. Key outcome measures were injury incidence and prevalence. Also recorded were self-reported measures of training exposures and intensity, injury classification, treatment received, duration of injury and where (geographical location) the injury occurred. Comparison of participant and therapist injury classification were made, and all outcome measures were calculated for the squad as a whole, as well as with breakdown for gender and squad. Results: Data were collected from 33 members of the elite NZ track cycling squad, comprising 17 males (17-32 years - mean 22.71, SD: 4.45), and 16 females (17-31 years - mean 21.5 years, SD: 4.82). 21 of the 33 participants sustained an injury during the period of inclusion in the study. Four reported injuring multiple body sites at one time, with one participant reporting two multi-site incidents during the period of data collection. 13 participants sustained multiple injuries, and 12 reported no incidence of injury. 11 injuries occurred in sports specific training, 20 in the gym, six in competition and seven other (mean 11, SD 6.38). 82% of injuries were recorded as being acute, 18% recurrent, with no overuse injuries reported. 8962 training exposures were planned (mean 689 exposures per four-weeks, SD 142), with 60 sessions (0.67%) missed and 84 (0.94%) modified due to injury, totalling 144/8962 (1.6%) training exposures affected by injury (mean 11.1, SD 7) per four-week block of surveys. Injury Incidence was 4.9 injuries per 1000 training and competition exposures. For all injuries sustained (53 body parts injured from 44 events), the injury incidence was 5.9 per 1000 exposures. Point prevalence ranged from one injury per four-week block to seven (mean 3.38, SD 1.80). No significant relationships were found between squad, gender, previous injury, years in sport, new injuries or injury frequency, or number of treatments. Conclusion: This research provides the first descriptive injury profile for the elite New Zealand track cycling cohort. 64% of participants sustained an injury over the study period, however injury incidence and prevalence was low with rapid return to training and competition. Greatest number of injuries was seen in the lower back, hip/buttock/pelvis region, and the knee, possibly reflecting the biomechanical requirements of cycling and the nature of the training required for this cohort. Previous studies investigating road cycling describe similar body sites injured, but with a large proportion classified as overuse whereas no overuse injuries were self-reported in this study. Further research is required to determine any reason for this. Total training exposures were recorded however little detail was documented on the intensity, nature and load of each specific training session and warrants more detailed investigation through future research

National laboratory-based surveillance system for antimicrobial resistance: a successful tool to support the control of antimicrobial resistance in the Netherlands

An important cornerstone in the control of antimicrobial resistance (AMR) is a well-designed quantitative system for the surveillance of spread and temporal trends in AMR. Since 2008, the Dutch national AMR surveillance system, based on routine data from medical microbiological laboratories (MMLs), has developed into a successful tool to support the control of AMR in the Netherlands. It provides background information for policy making in public health and healthcare services, supports development of empirical antibiotic therapy guidelines and facilitates in-depth research. In addition, participation of the MMLs in the national AMR surveillance network has contributed to sharing of knowledge and quality improvement. A future improvement will be the implementation of a new semantic standard together with standardised data transfer, which will reduce errors in data handling and enable a more real-time surveillance. Furthermore, the

Molecular characteristics of carbapenemase-producing Enterobacterales in the Netherlands; results of the 2014–2018 national laboratory surveillance

Objectives: Carbapenem resistance mediated by mobile genetic elements has emerged worldwide and has become a major public health threat. To gain insight into the molecular epidemiology of carbapenem resistance in The Netherlands, Dutch medical microbiology laboratories are requested to submit suspected carbapenemase-producing Enterobacterales (CPE) to the National Institute for Public Health and the Environment as part of a national surveillance system. Methods: Meropenem MICs and species identification were confirmed by E-test and MALDI-TOF and carbapenemase production was assessed by the Carbapenem Inactivation Method. Of all submitted CPE, one species/carbapenemase gene combination per person per year was subjected to next-generation sequencing (NGS). Results: In total, 1838 unique isolates were received between 2014 and 2018, of which 892 were unique CPE isolates with NGS data available. The predominant CPE species were Klebsiella pneumoniae (n = 388, 43%), Escherichia coli (n = 264, 30%) and Enterobacter cloacae complex (n = 116, 13%). Various carbapenemase alleles of the same carbapenemase gene resulted in different susceptibilities to meropenem and this effect varied between species. Analyses of NGS data showed variation of prevalence of carbapenemase alleles over time with blaOXA-48 being predominant (38%, 336/892), followed by blaNDM-1 (16%, 145/892). For the first time in the Netherlands, blaOXA-181, blaOXA-232 and blaVIM-4 were detected. The genetic background of K. pneumoniae and E. coli isolates was highly diverse. Conclusions: The CPE population in the Netherlands is diverse, suggesting multiple introductions. The predominant carbapenemase alleles are blaOXA-48 and blaNDM-1. There was a clear association between species, carbapenemase allele and susceptibility to meropenem

Chronic Q fever diagnosis—consensus guideline versus expert opinion

Chronic Q fever, caused by Coxiella burnetii, has high mortality and morbidity rates if left untreated. Controversy about the diagnosis of this complex disease has emerged recently. We applied the guideline from the Dutch Q Fe­ver Consensus Group and a set of diagnostic criteria pro­posed by Didier Raoult to all 284 chronic Q fever patients included in the Dutch National Chronic Q Fever Database during 2006–2012. Of the patients who had proven cas­es of chronic Q fever by the Dutch guideline, 46 (30.5%) would not have received a diagnosis by the alternative cri­teria designed by Raoult, and 14 (4.9%) would have been considered to have possible chronic Q fever. Six patients with proven chronic Q fever died of related causes. Until results from future studies are available, by which current guidelines can be modified, we believe that the Dutch lit­erature-based consensus guideline is more sensitive and easier to use in clinical practice

Dynamics of bacterial colonisation of the respiratory tract of patients with cystic fibrosis

Mutations in the human genome may result in altered phenotypes. The cystic fibrosis (CF) patient, for instance, suffers from an aberrant composition of the epithelial lining of the gastrointestinal and respiratory tract. In this particular case, a single point mutation in the cystic fibrosis conductance regulator (CFTR) gene results in major physiological changes resulting in ecological changes that generate a niche particularly attractive to a selected set of microbial pathogens. We here present a review on the dynamics of the bacterial populations inhabiting the CF lung. Studies focusing on Staphylococcus aureus, Haemophilus influenzae and Pseudomonas aeruginosa will be summarised and discussed, whereas the technology used for microbial characterisation will be shortly highlighted. Emphasis, however, will be on those studies that assessed the genetic diversity among clinical isolates that were obtained over prolonged periods of time, enabling the distinction between persistent colonisation versus frequent re-infection by the selected pathogens. Evolutionary adaptation of pathogens to the CF lung is a common theme in many of these studies. © 2001 Elsevier Science B.V. All rights reserved