European Journal of Clinical Microbiology Infectious Diseases

Xue, Q.; Wang, N.; Xue, X.; Wang, J.

doi: 10.1007/s10096-011-1205-2pmid: 21499709

Endobronchial tuberculosis (EBTB), of which the incidence has been increasing in recent years, is a special type of pulmonary tuberculosis. The endobronchial tuberculose focuses often injure the tracheobronchial wall and lead to tracheobronchial stenosis. The tracheobronchial stenosis may cause intractable tuberculosis and make patients become chronic infection sources of tuberculosis, or may even cause pulmonary complications and result in death. The etiological confirmation of Mycobacterium tuberculosis is most substantial for diagnosis. However, because the positive rate of acid-fast bacillus staining for sputum smears is low and the clinical and radiological findings are usually nondistinctive, the diagnosis of EBTB is often mistaken and delayed. For early diagnosis, a high index of awareness of this disease is required and the bronchoscopy should be performed as soon as possible in suspected patients. The eradication of Mycobacterium tuberculosis and the prevention of tracheobronchial stenosis are two most substantial treatment goals. To get treatment goals, the diagnosis must be established early and aggressive treatments must be performed before the disease progresses too far.

Egea, P.; López-Cerero, L.; Navarro, M.; Rodríguez-Baño, J.; Pascual, A.

doi: 10.1007/s10096-011-1168-3pmid: 21755280

The principal objective of this study was to assess whether chicken eggshells may be contaminated by ESBL-producing E. coli (ESBLC). Additional analyses were carried out to determine if ESBLEC could be detected in other foodstuffs such as cooked poultry or fresh vegetables. Seventy-two eggshells from different supermarkets and stores as well as 32 salads, 30 samples of cooked poultry and six samples of chicken-based pet food samples were analysed. Characterization of ESBL was performed by PCR and sequencing. Antimicrobial resistance was determined by disk diffusion method. Phylogenetic group was assigned by multiplex-PCR. No ESBLEC was isolated from chicken eggshells, cooked chicken and pet food. One SHV-12-producing E. coli was isolated from a salad sample. This is the first study to analyse chicken eggs in an area where there is a high prevalence of ESBLEC in retail chicken meat.

Lorente, L.; Jiménez, A.; Roca, I.; Martín, M.; Mora, M.

doi: 10.1007/s10096-011-1190-5pmid: 21301912

There are no data about the influence of tracheostomy in the incidence of catheter-related bloodstream infection (CRBSI) on the catheterization of the jugular vein by posterior access and there are no recommendations relating to this circumstance in the guidelines of the Centers for Disease Control and Prevention (CDC) and of Healthcare Epidemiology of America/Infectious Diseases Society of America (SHEA/IDSA) for the prevention of CRBSI. The novel finding of this observational study was that there was a higher incidence of CRBSI in the catheterization of jugular vein by posterior access in patients with tracheostomy than without it (13.24 vs 0 episodes of CRBSI per 1,000 catheter-day; odds ratio = 23.92; 95% CI = 1.86-infinite; p = 0.008). Thus, the presence of tracheostomy is a risk factor of CRBSI on the catheterization of jugular vein by posterior access.

Tongeren, S.; Degener, J.; Harmsen, H.

doi: 10.1007/s10096-011-1191-4pmid: 21311936

The development of fast and easy on-site molecular detection and quantification methods for hazardous microbes on solid surfaces is desirable for several applications where specialised laboratory facilities are absent. The quantification of bacterial contamination necessitates the assessment of the efficiency of the used methodology as a whole, including the preceding steps of sampling and sample processing. We used quantitative real-time polymerase chain reaction (qrtPCR) for Escherichia coli and Staphylococcus aureus to measure the recovery of DNA from defined numbers of bacterial cells that were subjected to three different DNA extraction methods: the QIAamp® DNA Mini Kit, Reischl et al.’s method and FTA® Elute. FTA® Elute significantly showed the highest median DNA extraction efficiency of 76.9% for E. coli and 108.9% for S. aureus. The Reischl et al. method and QIAamp® DNA Mini Kit inhibited the E. coli qrtPCR assay with a 10-fold decrease of detectable DNA. None of the methods inhibited the S. aureus qrtPCR assay. The FTA® Elute applicability was demonstrated with swab samples taken from the International Space Station (ISS) interior. Overall, the FTA® Elute method was found to be the most suitable to selected criteria in terms of rapidity, easiness of use, DNA extraction efficiency, toxicity, and transport and storage conditions.

Edmundson, S.; Hirpara, K.; Bennett, D.

doi: 10.1007/s10096-011-1192-3pmid: 21311935

Methicillin-resistant Staphylococcus aureus (MRSA) infections are associated with increased mortality, costs and length of stay compared to non-MRSA infections. This observational 4-year study analyses the impact of screening and treating orthopaedic healthcare workers for MRSA colonisation. A total of 1,011 swabs were taken from 566 healthcare workers. Positive healthcare workers were treated with topical mupirocin to both anterior nares. The prevalence of MRSA colonisation on initial testing was 4.77%. The rate of positive MRSA colonisation of those tested on more than one occasion fell from 5.88% to 2.71% (p = 0.055) on subsequent screening. All healthcare workers receiving treatment were successfully cleared of colonisation; however, some required more than one course of treatment. These results show that there could be a role for screening and treating orthopaedic staff for MRSA colonisation as part of a strategy to reduce the prevalence of MRSA infections in orthopaedic units.

Galikowska, E.; Kunikowska, D.; Tokarska-Pietrzak, E.; Dziadziuszko, H.; Łoś, J.; Golec, P.; Węgrzyn, G.; Łoś, M.

doi: 10.1007/s10096-011-1193-2pmid: 21318732

The use of bacteriophages, instead of antibodies, in the ELISA-based detection of bacterial strains was tested. This procedure appeared to be efficient, and specific strains of Salmonella enterica and Escherichia coli could be detected. The sensitivity of the assay was about 105 bacterial cells/well (106/ml), which is comparable with or outperforms other ELISA tests detecting intact bacterial cells without an enrichment step. The specificity of the assay depends on the kind of bacteriophage used. We conclude that the use of bacteriophages in the detection and identification of bacteria by an ELISA-based method can be an alternative to the use of specific antibodies. The advantages of the use of bacteriophages are their environmental abundance (and, thus, a possibility to isolate various phages with different specificities) and the availability of methods for obtaining large amounts of phage lysates, which are simple, rapid, cheap, and easy.

Qureshi, H.; Qazi, R.; Hamid, S.; Qureshi, S.

doi: 10.1007/s10096-011-1194-1pmid: 21318731

Hepatitis C virus (HCV) encodes ten classic proteins as well as a newly discovered alternative reading frame protein (ARFP) whose synthesis originates from the core region by a +1 frameshift. ARFP is produced by all HCV genotypes, but its function remains unknown. Although the immunogenicity of genotype 1- and 2-derived ARFP in infected hosts has been reported, no information is available for genotype 3-encoded ARFP. HCV genotype 3 core/ARFP region was PCR amplified, cloned, and sequenced. Recombinant ARFP and peptides were employed in ELISAs with patient serum samples. The effect of peptides on peripheral blood mononucleocytes (PBMCs) was also studied. DNA cloning and sequencing of HCV genotype 3 strain (PKHCV3) revealed it to encode 160 aa ARFP, which harbors a C-terminal extension of 36 aa. Serum from 74 of 88 patients (84%) contained rARFP-reactive antibodies. Peptide ELISAs showed that all regions of rARFP were immunogenic, with peptide F7 (DSLSPRRAGAKAGPGLSPGT) being the most immunodominant. When incubated with PBMCs from HCV-infected individuals, F7 stimulated the production of TNFα and IL10. PKHCV3-derived ARFP encodes a 160 aa protein and antibodies against its entire length are found in 84% of all genotype 3-infected subjects. Peptide ELISAs revealed F7 to be highly immunogenic and capable of eliciting impressive T-cell responses.

Lelyveld, S.; Wind, C.; Mudrikova, T.; Leeuwen, H.; Lange, D.; Hoepelman, A.

doi: 10.1007/s10096-011-1196-zpmid: 21331480

The purpose of this investigation was to analyse the impact of the availability of highly active antiretroviral therapy (HAART) on the long-term outcome of human immunodeficiency virus (HIV)-infected patients admitted to the intensive care unit (ICU). A retrospective cohort study of HIV-infected patients admitted to the ICU was undertaken. Outcomes in the pre-HAART era (1990–June 1996), early- (July 1996–2002), and recent-HAART (2003–2008) periods and total HAART era (July 1996–2008) were analysed and compared with those reported of the general population. A total of 127 ICU admissions were included. The 1-year mortality decreased from 71% in the pre-HAART era to 50% in the recent-HAART period (p = 0.06). The 5-year mortality decreased from 87% in the pre-HAART era to 59% in the early-HAART period (p = 0.005). Independent predictors of 1-year mortality in the HAART era were age (odds ratio [OR] = 1.16 [95% confidence interval [CI] = 1.06–1.27]), APACHE II score > 20 (6.04 [1.25–29.22]) and mechanical ventilation (40.01 [3.01–532.65]). The 5-year survival after hospitalisation was 80% and in the range of the reported survival of non-HIV-infected patients (83.7%). Predictors of 1-year mortality for HIV patients admitted to the ICU in the HAART era were all non-HIV-related. Short- and long-term outcome has improved since the introduction of HAART and is comparable to the outcome data in non-HIV-infected ICU patients.

Kresken, M.; Becker, K.; Seifert, H.; Leitner, E.; Körber-Irrgang, B.; Eiff, C.; Löschmann, P.-A.

doi: 10.1007/s10096-011-1197-ypmid: 21347680

To document the development of resistance to tigecycline in comparison with 17 other antimicrobials, the susceptibilities of 2,741 isolates comprising 16 bacterial species recovered from hospitalised patients in 15 German centres in 2009 were assessed. The results were compared with those of previous trials (German Tigecycline Evaluation Surveillance Trial, G-TEST I and II, performed in 2005 and 2007, respectively) conducted prior to and shortly after the introduction of tigecycline in Germany. Moreover, the in vitro activities of tigecycline against the subset of multidrug-resistant (MDR) pathogens recovered within all three sampling periods (n = 4,988) were evaluated in comparison to the corresponding non-MDR isolates. All susceptibility tests were performed by broth microdilution. Between 2005 and 2009, tigecycline retained its high activity against Gram-positive and Gram-negative organisms, including MDR pathogens. By contrast, an in part marked increase in resistance to broad-spectrum beta-lactams and fluoroquinolones was observed for many Enterobacteriaceae and for non-fermenting Gram-negative bacteria. Against a background of a steadily increasing number of multiresistant pathogens, the activity of tigecycline remained unaltered. With the exception of Acinetobacter isolates with decreased susceptibility to carbapenems, tigecycline’s activity profile was not notably affected by organisms resistant to other drug classes and, thus, holds promise as an important therapeutic agent, particularly for situations in which MDR organisms are suspected.

Gelardi, M.; Passalacqua, G.; Fiorella, M.; Mosca, A.; Quaranta, N.

doi: 10.1007/s10096-011-1198-xpmid: 21359623

The purpose of this study was to describe some “morphological-chromatic” patterns (i.e. spots of cyan colour) identified during the study of nasal cytology in patients with both bacterial and fungal infectious rhinological disorders. These peculiar aspects strongly suggest the presence of a microscopic biofilm. We retrospectively examined 1,410 nasal cytology specimens from subjects who underwent clinical-instrumental investigations (history, ENT visit, nasal endoscopy and nasal cytology) from January to August 2010. The control samples were represented by 30 subjects not suffering from infectious rhinological diseases. The presence of particular spots of “cyan” was found in colour in 107/1,410 rhinocytograms (7.6%), within which bacterial colonies and/or fungal spores were found. We called these coloured spot formations “infectious spots” (IS). The positivity to periodic acid Schiff (PAS) staining confirmed the polysaccharide nature of the coloured spots and allowed us to relate them to biofilms. This study demonstrates, for the first time, that nasal cytology performed by optical microscope can play an important role in detecting biofilms.