We were not able to identify the common source for these cases of infection, but the adopted measures have proven to be effective at controlling the outbreak.

The members of the Mycobacterium tuberculosis complex (MTC) cause tuberculosis (TB). Infection is transmitted within and between livestock and wildlife populations, thus hampering TB control. Indirect transmission might be facilitated if MTC bacteria persist in the environment long enough to represent a risk of exposure to different species sharing the same habitat. We have, for the first time, addressed the relationship between environmental MTC persistence and the use of water resources in two TB endemic areas in southern Spain with the objective of identifying the presence of environmental MTC and its driving factors at ungulates' water aggregation points. Camera-trap monitoring and MTC diagnosis (using a new MTC complex-specific PCR technique) were carried out at watering sites. Overall, 55.8% of the water points tested positive for MTC in mud samples on the shore, while 8.9% of them were positive in the case of water samples. A higher percentage of MTC-positive samples was found at those waterholes where cachectic animals were identified using camera-trap monitoring, and at the smallest waterholes. Our results help to understand the role of indirect routes of cross-species TB transmission and highlight the importance of certain environmental features in maintaining infection in multihost systems. This will help to better target actions and implement control strategies for TB at the wildlife/livestock interface.

Objectives Escherichia coli is characterized by three resistance patterns to β-lactams/β-lactamase inhibitors (BLs/BLIs): (i) resistance to ampicillin/sulbactam and susceptibility to amoxicillin/clavulanic acid and piperacillin/tazobactam (RSS); (ii) resistance to ampicillin/sulbactam and amoxicillin/clavulanic acid, and susceptibility to piperacillin/tazobactam (RRS); and (iii) resistance to ampicillin/sulbactam, amoxicillin/clavulanic acid and piperacillin/tazobactam (RRR). These resistance patterns are acquired consecutively, indicating a potential risk of developing resistance to piperacillin/tazobactam, but the precise mechanism of this process is not completely understood. Methods Clinical isolates incrementally pressured by piperacillin/tazobactam selection in vitro and in vivo were used. We determined the MIC of piperacillin/tazobactam in the presence and absence of piperacillin/tazobactam pressure. We deciphered the role of the blaTEM genes in the new concept of extended-spectrum resistance to BLs/BLIs (ESRI) using genomic analysis. The activity of β-lactamase was quantified in these isolates. Results We show that piperacillin/tazobactam resistance is induced in E. coli carrying blaTEM genes. This resistance is due to the increase in copy numbers and transcription levels of the blaTEM gene, thus increasing β-lactamase activity and consequently increasing piperacillin/tazobactam MICs. Genome sequencing of two blaTEM-carrying representative isolates showed that piperacillin/tazobactam treatment produced two types of duplications of blaTEM (8 and 60 copies, respectively). In the clinical setting, piperacillin/tazobactam treatment of patients infected by E. coli carrying blaTEM is associated with a risk of therapeutic failure. Conclusions This study describes for the first time the ESRI in E. coli. This new concept is very important in the understanding of the mechanism involved in the acquisition of resistance to BLs/BLIs.