The INNO-LiPA Rif.TB assay for the identification of Mycobacterium tuberculosis complex strains and the detection of rifampin (RIF) resistance has been evaluated with 360 smear-positive respiratory specimens from an area of high incidence of multidrug-resistant tuberculosis (MDR-TB). The sensitivity when compared to conventional identification/culture methods was 82.2%, and the specificity was 66.7%; the sensitivity and specificity were 100.0% and 96.9%, respectively, for the detection of RIF resistance. This assay has the potential to provide rapid information that is essential for the effective management of MDR-TB.

To investigate the epidemiological relationship of isolates from different Portuguese geographical regions and to assess the diversity among isolates, the MLVA16Orsay assay (panels 1, 2A and 2B) was performed with a collection of 126 Brucella melitensis (46 human and 80 animal isolates) and 157 B. abortus field isolates, seven vaccine strains and the representative reference strains of each species. The MLVA16Orsay showed a similar high discriminatory power (HGDI 0.972 and 0.902) for both species but panel 1 and 2A markers displayed higher diversity (HGDI 0.693) in B. abortus compared to B. melitensis isolates (HGDI 0.342). The B. melitensis population belong to the “Americas” (17%) and “East Mediterranean” (83%) groups. No isolate belonged to the “West Mediterranean” group. Eighty-five percent of the human isolates (39 in 46) fit in the “East-Mediterranean” group where a single lineage known as MLVA11 genotype 116 is responsible for the vast majority of Brucella infections in humans. B. abortus isolates formed a consistent group with bv1 and bv3 isolates in different clusters. Four MLVA11 genotypes were observed for the first time in isolates from S. Jorge and Terceira islands from Azores. From the collection of isolates analysed in this study we conclude that MLVA16Orsay provided a clear view of Brucella spp. population, confirming epidemiological linkage in outbreak investigations. In particular, it suggests recent and ongoing colonisation of Portugal with one B. melitensis lineage usually associated with East Mediterranean countries.

This study shows that efflux activity contributes to colistin heteroresistance in an MDR A. baumannii clinical isolate. The use of efflux inhibitors as adjuvants of the therapy can resensitize A. baumannii to colistin and prevent the emergence of drug resistance.

Colistin is a crucial last-line drug used for the treatment of life-threatening infections caused by multidrug-resistant strains of the Gram-negative bacterium However, colistin-resistant isolates can still be isolated following failed colistin therapy. Resistance is most often mediated by the addition of phosphoethanolamine (pEtN) to lipid A by PmrC, following missense mutations in the operon encoding PmrC and the two-component signal transduction system PmrA/PmrB. We recovered a pair of isolates from a single patient before (6009-1) and after (6009-2) failed colistin treatment. These strains displayed low and very high levels of colistin resistance (MICs, 8 to 16 μg/ml and 128 μg/ml), respectively. To understand how increased colistin resistance arose, we sequenced the genome of each isolate, which revealed that 6009-2 had an extra copy of the insertion sequence element IS within a gene encoding an H-NS family transcriptional regulator. To confirm the role of H-NS in colistin resistance, we generated an deletion mutant in 6009-1and showed that colistin resistance increased upon the deletion of We also provided 6009-2 with an intact copy of and showed that the strain was no longer resistant to high concentrations of colistin. Transcriptomic analysis of the clinical isolates identified more than 150 genes as being differentially expressed in the colistin-resistant mutant 6009-2. Importantly, the expression of, encoding a second lipid A-specific pEtN transferase but not , was increased in the mutant. This is the first time an H-NS family transcriptional regulator has been associated with a pEtN transferase and colistin resistance.

Cerebral phaeohyphomycosis is an infrequent infectious condition associated with a high mortality rate. The authors describe a very rare case that occurred in an immunocompetent 18-year-old man who developed severe meningoencephalitis and arachnoiditis caused by Alternaria alternata, which were diagnosed in the context of difficult-to-treat hydrocephalus. Etiological diagnosis was made based on fungal culture and histopathologic examination. Empirical treatment consisted of an early aggressive antifungal combination therapy consisting of intravenous liposomal amphotericin B (5 mg/kg per day) and voriconazole (4 mg/kg every 12 h), which initially induced a favorable response. Following the fungus identification, the choice for the combination of posaconazole (400 mg every 12 h) plus flucytosine (4000 mg/day) proved to be effective in the suppression of the signs and symptoms of this uncommon cerebral mycosis. At a 12-month follow-up visit no recurrence had occurred and posaconazole was then stopped.