Impact of nasopharyngeal microbiota on the development of respiratory tract diseasesEsposito, S.; Principi, N.
doi: 10.1007/s10096-017-3076-7pmid: 28795339
Knowledge of whether and how respiratory microbiota composition can prime the immune system and provide colonisation resistance, limiting consecutive pathobiont overgrowth and infections, is essential to improving the prevention and therapy of respiratory disorders. Modulation of dysbiotic ecosystems or reconstitution of missing microbes might be a possible measure to reduce respiratory diseases. The aim of this review is to analyse the role of nasopharyngeal microbiota in the development of respiratory tract disease in paediatric-age subjects. PubMed was used to search for all studies published over the last 15 years using the following key words: “microbiota” or “microbioma” and “nasopharyngeal” or “respiratory” or “nasal” and “children” or “paediatric” or “infant”. Analysis of the literature showed that respiratory microbiota can regulate health and disease development in the respiratory tract. Like the gut microbiota, the respiratory microbiota is established at birth, and early respiratory microbiota composition determines bacterial succession patterns and respiratory health in children. Protective and dangerous bacteria have been identified, and this can be considered the base for developing new approaches to diseases that respond poorly to traditional interventions. Reconstitution of missing microbes can be achieved by the administration of pre- and probiotics. Modulation of respiratory microbiota by favouring colonisation of the upper respiratory tract by beneficial commensals can interfere with the proliferation and activity of resident pathobionts and is a possible new measure to reduce the risk of disease. However, further studies are needed because a deeper understanding of these and related issues can be transferred to clinical practice.
The reliability of rifampicin resistance as a proxy for multidrug-resistant tuberculosis: a systematic review of studies from IranNasiri, M.; Zamani, S.; Pormohammad, A.; Feizabadi, M.; Aslani, H.; Amin, M.; Halabian, R.; Imani Fooladi, A.
doi: 10.1007/s10096-017-3079-4pmid: 28823010
In Iran, patients showing rifampicin (RIF) resistance detected by the Xpert® MTB/RIF assay are considered as candidates for multidrug-resistant tuberculosis (MDR-TB) treatment. Despite the fact that RIF resistance has been used as a proxy for MDR-TB, little is known about the proportion of isoniazid (INH) resistance patterns in RIF-resistant TB. We systematically searched MEDLINE, Embase, and other databases up to March 2017 for studies addressing the proportion of INH resistance patterns in RIF-resistant TB in Iran. The data were pooled using a random effects model. Heterogeneity was assessed using Cochran’s Q and I2 statistics. A total of 11 articles met the eligibility criteria. Data analysis demonstrated that 33.3% of RIF-resistant isolates from new TB cases and 14.8% of RIF-resistant isolates from previously treated cases did not display resistance to INH. The relatively high proportion of INH susceptibility among isolates with RIF resistance indicated that RIF resistance may no longer predict MDR-TB in Iran. Therefore, the detection of RIF resistance by the Xpert MTB/RIF assay will require complementary detection of INH resistance by other drug susceptibility testing (DST) methods in order to establish the diagnosis of MDR-TB.
Similarities and differences between doxycycline and minocycline: clinical and antimicrobial stewardship considerationsCunha, B.; Baron, J.; Cunha, C.
doi: 10.1007/s10096-017-3081-xpmid: 28819873
Doxycycline and, to a lesser extent, minocycline, have been used for decades to treat various serious systemic infections, but many physicians remain unfamiliar with their spectrum, interpretation of susceptibility results, pharmacokinetic/pharmacodynamic (PK/PD) properties, optimal dosing regimens, and their activity against MRSA, VRE, and multidrug-resistant (MDR) Gram-negative bacilli, e.g., Acinetobacter sp. This article reviews the optimal use of doxycycline and minocycline to treat a variety of infections and when minocycline is preferred instead of doxycycline.
Infection control interventions affected by resource shortages: impact on the incidence of bacteremias caused by carbapenem-resistant pathogensKousouli, E.; Zarkotou, O.; Politi, L.; Polimeri, K.; Vrioni, G.; Themeli-Digalaki, K.; Tsakris, A.; Pournaras, S.
doi: 10.1007/s10096-017-3098-1pmid: 28879405
We evaluated an infection control (IC) program influenced by personnel and material resource shortages on the incidence of bloodstream infections (BSI) due to carbapenem-resistant Klebsiella pneumoniae (CRKP), Acinetobacter baumannii (CRAB), and Pseudomonas aeruginosa (CRPA) in an endemic region. Between January 2010 and December 2015, all BSI episodes caused by CRKP, CRAB, and CRPA were recorded. An IC bundle was implemented in January 2012. We evaluated the effect of the interventions on BSI rates between the pre-intervention (2010–2011) and intervention (2012–2013) periods, using an interrupted time-series model. From 2014, when interventions were still applied, BSI incidence was gradually increased. For this reason, we evaluated with a linear mixed effects model several factors possibly contributing to this increase for the years 2012–2015, which was considered as the intervention/follow-up period. During the study period, 351 patients with BSI were recorded, with a total of 538 episodes; the majority (83.6%) occurred in the intensive care unit (ICU). The BSI incidence rate per year during 2010–2015 for ICU patients was 21.03/19.63/17.32/14.45/22.85/25.02 per 1000 patient-days, respectively, with the reduction in BSI levels after the start of intervention marginal (p = 0.054). During the follow-up period (2014–2015), the most influential factors for the increased BSI incidence were the reduced participation in educational courses and compliance with hand hygiene. The implementation of IC interventions reduced the BSI incidence rates, particularly for ICU patients. However, factors possibly related to the restrictions of human and material resources apparently contributed to the observed expansion of BSI in our endemic setting.
Development of a rapid MALDI-TOF MS based epidemiological screening method using MRSA as a model organismLindgren, Åsa; Karami, Nahid; Karlsson, Roger; Åhrén, Christina; Welker, Martin; Moore, Edward; Stadler, Liselott
doi: 10.1007/s10096-017-3101-xpmid: 28924947
In this study we present a method using whole cell MALDI-TOF MS and VITEK MS RUO/SARAMIS as a rapid epidemiological screening tool. MRSA was used as a model organism for setting up the screening strategy. A collection of well-characterised MRSA strains representing the 19 most common Pulsed-Field Gel Electrophoresis (PFGE)-types in the region of South-West Sweden for the past 20 years was analysed with MALDI-TOF MS. A total of 111 MRSA strains were used for creating 19 PFGE-specific Superspectra using VITEK MS RUO/SARAMIS. Prior to performing the final analysis, the 19 Superspectra were combined into ten groups displaying similar peak patterns, hereafter named “MALDI-types”. Two-hundred fifty-five MRSA strains were analysed to test the constructed Superspectra/MALDI-type database. Matches to the Superspectra above a threshold of 65% (corresponding to the number of matched peaks in the Superspectrum) were considered as positive assignment of a strain to a MALDI-type. The median peak matching value for correct assignment of a strain to a MALDI-type was 78% (range 65.3–100%). In total, 172 strains (67.4%) were assigned to the correct MALDI-type and only 5.5% of the strains were incorrectly assigned to another MALDI-type than the expected based on the PFGE-type of the strain. We envision this methodology as a cost-efficient step to be used as a first screening strategy in the typing scheme of MRSA isolates, to exclude epidemiological relatedness of isolates or to identify the need for further typing.
Prevalence and risk factors for intestinal carriage of CTX-M-type ESBLs in Enterobacteriaceae from a Thai communityNiumsup, P.; Tansawai, U.; Na-udom, A.; Jantapalaboon, D.; Assawatheptawee, K.; Kiddee, A.; Romgaew, T.; Lamlertthon, S.; Walsh, T.
doi: 10.1007/s10096-017-3102-9pmid: 28918585
The incidence of infections caused by antimicrobial-resistant Enterobacteriaceae in Thailand is increasing and human intestinal flora is an important reservoir for these organisms. This study was carried out to determine the intestinal carriage of bla
CTX-M extended spectrum ß-lactamase-positive Enterobacteriaceae (ESBL + E) and AmpC-positive Enterobacteriaceae in a community setting in Northern Thailand, and to identify potential risk factors for carriage. A total of 307 fecal samples were collected from healthy volunteers in Phitsanulok province, and cefotaxime-resistant Enterobacteriaceae (CtxRE) were isolated using selective media. Polymerase chain reaction (PCR) was used to detect ESBL and AmpC genes. Risk factors were analyzed using multiple logistic regression. Genotyping was performed by multilocus sequence typing (MLST) analysis. Two hundred ninety-one CtxRE isolates were obtained and Escherichia coli was the predominant organism (66.3%). The intestinal carriage rates of bla
CTX-M ESBL + E and AmpC-positive Enterobacteriaceae were 52.1% and 6.2%, respectively. Comparative levels of bla
CTX-M group 1 and bla
CTX-M group 9 were found while bla
CMY-2 was the predominant genotype among AmpC genes. Co-existence of two ß-lactamase genes in a single isolate was found in 6.5% of isolates. Consumption of undercooked meat was strongly associated with intestinal carriage of bla
CTX-M ESBL + E (p = 0.003, OR = 2.133, 95% CI = 1.289–3.530). Phylogenetic grouping and MLST analysis of E. coli isolates revealed the presence of E. coli B2-ST131 (n = 8). Of these, seven carried bla
CTX-M-group 9 and 1 carried bla
CMY-2. Our results suggest that residents in Thailand are at high risk for developing endogenous infections caused by antibiotic-resistant Enterobacteriaceae.
Clinical significance of Aspergillus species isolated from respiratory specimens in patients with Mycobacterium avium complex lung diseaseFuruuchi, K.; Ito, A.; Hashimoto, T.; Kumagai, S.; Ishida, T.
doi: 10.1007/s10096-017-3105-6pmid: 28920166
Chronic pulmonary aspergillosis (CPA) is associated with mortality in patients with Mycobacterium avium complex lung disease (MAC-LD). An Aspergillus-positive respiratory specimen often reflects colonization, and thus the clinical significance of Aspergillus isolation in MAC-LD patients is not well understood. The objective of this study was to investigate the clinical characteristics and outcomes of MAC-LD patients in whom Aspergillus was isolated from respiratory specimens. We performed a retrospective review of the medical records of 329 MAC-LD patients. We compared the characteristics and mortality rates between patients with Aspergillus isolation and those without. All Aspergillus species detected from respiratory specimens within the follow-up period were reviewed. Aspergillus was detected in 40 (12.2%) of the 329 patients. There were no significant differences in the clinical characteristics and mortality rates between patients with and without Aspergillus isolation. Among the 40 patients with Aspergillus isolation, 9 (22.5%) developed CPA. CPA was most often caused by A. fumigatus. In the 40 Aspergillus-positive patients, patients with A. fumigatus isolation had a significantly higher mortality rate than those without (P < 0.001). The multivariate Cox proportional hazards model showed older age (P = 0.050), presence of respiratory comorbidities (P = 0.008), hypoalbuminemia (P < 0.001), and isolation of A. fumigatus (P = 0.005) to be prognostic factors for mortality in MAC-LD patients. There was no significant difference in the mortality rates between patients with Aspergillus isolation and those without. However, isolation of A. fumigatus may be associated with poor prognosis in MAC-LD patients.