cThe treatment of drug-resistant tuberculosis cases is challenging, as drug options are limited, and the existing diagnostics are inadequate. Whole-genome sequencing (WGS) has been used in a clinical setting to investigate six cases of suspected extensively drug-resistant Mycobacterium tuberculosis (XDR-TB) encountered at a London teaching hospital between 2008 and 2014. Sixteen isolates from six suspected XDR-TB cases were sequenced; five cases were analyzed in a clinically relevant time frame, with one case sequenced retrospectively. WGS identified mutations in the M. tuberculosis genes associated with antibiotic resistance that are likely to be responsible for the phenotypic resistance. Thus, an evidence base was developed to inform the clinical decisions made around antibiotic treatment over prolonged periods. All strains in this study belonged to the East Asian (Beijing) lineage, and the strain relatedness was consistent with the expectations from the case histories, confirming one contact transmission event. We demonstrate that WGS data can be produced in a clinically relevant time scale some weeks before drug sensitivity testing (DST) data are available, and they actively help clinical decision-making through the assessment of whether an isolate (i) has a particular resistance mutation where there are absent or contradictory DST results, (ii) has no further resistance markers and therefore is unlikely to be XDR, or (iii) is identical to an isolate of known resistance (i.e., a likely transmission event). A small number of discrepancies between the genotypic predictions and phenotypic DST results are discussed in the wider context of the interpretation and reporting of WGS results. In 2013, of the 6.1 million new tuberculosis (TB) cases reported worldwide, 480,000 were defined as multidrug resistant (MDR) (1). MDR strains of Mycobacterium tuberculosis are defined as those that are resistant to the key first-line drugs, rifampin (RIF) and isoniazid (INH). Such cases need to be treated using a more complex and flexible drug selection algorithm than the standard, with a combination of at least four drugs from an available panel classified according to their mode of action, efficacy, and clinical experience, and should be further modified if other resistances become apparent (2).Extensively drug-resistant (XDR) strains of M. tuberculosis are defined as MDR strains that in addition to being RIF and INH resistant are also resistant to the two most effective remaining bactericidal drug classes, at least one fluoroquinolone (FLQ), and one second-line injectable agent (amikacin [AMI] or kanamycin [KAN], or capreomycin [CAP]). The XDR designation reflects the concern that these are even more difficult to treat. Globally, in 2014, 9.0% of MDR cases were reported as being XDR (1); these figures are likely to be underestimates, because testing and reporting practices are not universal.The overall rates of TB in the United Kingdom have been stable, at ϳ14 per 100,000 since 2005, with London having the highest regional ...
Drug-resistant tuberculosis (TB) remains a major challenge to global health and to healthcare in the UK. In 2014, a total of 6,520 cases of TB were recorded in England, of which 1.4 % were multidrug-resistant TB (MDR-TB). Extensively drug-resistant TB (XDR-TB) occurs at a much lower rate, but the impact on the patient and hospital is severe. Current diagnostic methods such as drug susceptibility testing and targeted molecular tests are slow to return or examine only a limited number of target regions, respectively. Faster, more comprehensive diagnostics will enable earlier use of the most appropriate drug regimen, thus improving patient outcomes and reducing overall healthcare costs. Whole genome sequencing (WGS) has been shown to provide a rapid and comprehensive view of the genotype of the organism, and thus enable reliable prediction of the drug susceptibility phenotype within a clinically relevant timeframe. In addition, it provides the highest resolution when investigating transmission events in possible outbreak scenarios. However, robust software and database tools need to be developed for the full potential to be realized in this specialized area of medicine.
Diarrhoea and weight loss are found in more than 50% of patients with the acquired immunodeficiency syndrome (AIDS). In some patients the symptoms can be very severe, leading to death even in the absence of opportunistic infections. In 30% of these patients, enteric pathogens cannot be identified, and approximately only half of the identifiable aetiologic agents of diarrhoea in patients infected with the human immunodeficiency virus (HIV) were treatable with antibiotics. Immunoglobulins from bovine colostrum (Lactobin, Biotest, Dreieich, FRG) contain high titers of antibodies against a wide range of bacterial, viral and protozoal pathogens as well as against various bacterial toxins. Lactobin (LIG) is quite resistant to 24-h incubation with gastric juice. In a multi-center pilot study 37 immunodeficiency patients with chronic diarrhoea [29 HIV-infected patients, 2 patients with common variable immunodeficiency (CVID), one unidentified immunodeficiency, five patients with graft versus host disease (GvHD) following bone marrow transplantation] were treated with oral LIG (10 g/day for 10 days). Good therapeutic effects were observed. Out of 31 treatment periods in 29 HIV-infected patients 21 gave good results leading to transient (10 days) or long-lasting (more than 4 weeks) normalisation of the stool frequency. The mean daily stool frequency decreased from 7.4 to 2.2 at the end of the treatment. Eight HIV-infected patients showed no response. The diarrhoea recurred in 12 patients within 4 weeks (32.4%), while 19 patients were free of diarrhoea for at least 4 weeks (51.3%). In 5 patients intestinal cryptosporidiosis disappeared following oral LIG treatment. LIG treatment was also beneficial in 4 out of 5 GvHD patients.(ABSTRACT TRUNCATED AT 250 WORDS)
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