Tuberculosis (TB) is a universal disease: it occurs all over the globe, albeit with hugely varying regional incidence. Especially in Asian and African countries, the incidence and prevalence may be extremely high. The European Journal of Clinical Microbiology and Infectious Diseases published seven papers on TB in 2013, representing 3.3 % (7/211) of its annual production. Four of the papers concerned mechanistic studies on clinical patient management, cost-effectiveness of antibiotic treatment, importance of microbiota and host genetic polymorphisms, respectively. The other three papers concerned molecular diagnostics, so, overall, hardly any attention was paid to the more classical modes of diagnosing TB. And this clearly contrasts with international needs, since classical diagnostics is still very high on the agenda in those countries where TB testing is most needed. In their 2013 Global Tuberculosis Report, the World Health Organization (WHO) claimed that culture is still the reference method for the detection of Mycobacterium tuberculosis (Mtb), with smear staining and microscopy being considered as a method of "added value". Hence, a wide array of culture systems has been developed by a large multitude of researchers and companies. Some of these are semi-automated, but most require manual intervention. Löwenstein-Jensen medium (LJ) is frequently considered the key mycobacterial growth medium when comparative studies for the verification and validation of new diagnostic tests are performed. Even the validation of liquid media in combination with semi-automated culture systems is usually performed in comparison with LJ-based cultivation as the diagnostic Gold Standard.We have set out to investigate the quality of some of the culture media proposed for the detection of Mtb in order to verify whether such media really are the appropriate Gold Standard tools for the validation of novel TB diagnostics. We performed a literature search (PubMed dd 13 August 2013) for the period between January 2008 and August 2013. In this way, 71 relevant articles were identified, of which the 19 most complete studies were selected for more detailed analysis. We collected the number of specimens tested, the culture medium used and identified, where possible, the manufacturer of the media. As such, six different producers of culture media for Mtb detection were identified. When microscopic observation of drug susceptibility (MODS) was performed, we included these data as well.Overall, the highest sensitivities and negative predictive values were shown by the BACTEC MGIT 960 System (Becton-Dickinson, Sparks, MD, USA), either when used alone or in combination with LJ. The latter combination provided the best sensitivity and also scored particularly well in the detection of non-tuberculous mycobacteria. The highest specificity and positive predictive values were shown by the LJ method itself, which obviously produced no falsepositives. So, MGIT is the top performer with regard to sensitivity, while LJ sets the current standard for spe...

Hospital-acquired infections (HAIs) are a cause of continuously increasing morbidity and mortality. Most of these infections are caused by a limited set of bacterial species, which share the capability to efficiently spread from patient to patient and to easily acquire antibiotic resistance determinants. This renders correct and rapid species identification and antibiotic susceptibility testing (AST) important and underscores the relevance of bacterial epidemiological typing. The latter is needed for the sensitive detection and exact tracing of nosocomial spread of these potentially multidrug-resistant microorganisms (MDRO). Many microbial typing technologies have been developed and put to some level of executive practice, but it seems that the continued evolution in methodology has currently reached an apex: there is likely to be scientific and practical consensus on the ultimate typing potential of bacterial whole-genome sequencing (WGS). The possibility to perform pan-genomic nucleotide-to-nucleotide comparisons between strains belonging to a single species and to detect even minute changes in nucleotide order will identify closely related organisms, while upon accumulation of such mutations, independent descend can be assumed. Calibration of difference levels [i.e. number of single nucleotide polymorphisms (SNPs)] into categories of inter-strain relatedness needs to be performed in order to generate robust, portable typing schemes. Here, we will briefly discuss the state of affairs regarding bacterial epidemiology based upon WGS, its relatedness with the nomenclature of former typing approaches and the continuing need for a global typing language.