Fourier transform infrared (FT-IR) spectroscopy typing: a real-time analysis of an outbreak by carbapenem-resistant Klebsiella pneumoniae.

The spread of multidrug-resistant (MDR) Klebsiella pneumoniae in the nosocomial setting represents a big challenge to infection control teams. We have recently developed a simple spectroscopic-based method with excellent accuracy, turnaround time and cost-effectiveness (Rodrigues et al. mSystems 2020) for bacterial typing. Here, we applied our method in a real clinical context to support early identification of an outbreak involving KPC-3-producing K. pneumoniae ST147 isolates. Our results further support that attenuated total reflectance Fourier transform infrared (FT-IR) spectroscopy can provide enough information to support early and adequate infection control measures and therapeutic choices in the context of nosocomial outbreaks and hospital surveillance.

Multiplicity of Carbapenemase-Producers Three Years after a KPC-3-Producing K. pneumoniae ST147-K64 Hospital Outbreak.

Carbapenem resistance rates increased exponentially between 2014 and 2017 in Portugal (~80%), especially in Klebsiella pneumoniae. We characterized the population of carbapanemase-producing Enterobacterales (CPE) infecting or colonizing hospitalized patients (2017-2018) in a central hospital from northern Portugal, where KPC-3-producing K. pneumoniae capsular type K64 has caused an initial outbreak. We gathered phenotypic (susceptibility data), molecular (population structure, carbapenemase, capsular type) and biochemical (FT-IR) data, together with patients' clinical and epidemiological information. A high diversity of Enterobacterales species, clones (including E. coli ST131) and carbapenemases (mainly KPC-3 but also OXA-48 and VIM) was identified three years after the onset of carbapenemases spread in the hospital studied. ST147-K64 K. pneumoniae, the initial outbreak clone, is still predominant though other high-risk clones have emerged (e.g., ST307, ST392, ST22), some of them with pandrug resistance profiles. Rectal carriage, previous hospitalization or antibiotherapy were presumptively identified as risk factors for subsequent infection. In addition, our previously described Fourier Transform infrared (FT-IR) spectroscopy method typed 94% of K. pneumoniae isolates with high accuracy (98%), and allowed to identify previously circulating clones. This work highlights an increasing diversity of CPE infecting or colonizing patients in Portugal, despite the infection control measures applied, and the need to improve the accuracy and speed of bacterial strain typing, a goal that can be met by simple and cost-effective FT-IR based typing.

[Pulmonary manifestations of autoimmune diseases]. / Manifestações pulmonares de patologias auto-imunes.

The lung is a unique interface between the antigen and the circulating blood volume. It is submitted to extrinsic/intrinsic challenges and is particularly vulnerable to circulating insulting agents. It is a site of intense immune surveillance, allowing antigen sampling to expand the immunologic repertoire through lymphocyte recirculation. In addition, local inflammatory reactions to antigens are generated. Imaging has an important role in diagnosis of patients with immunologic lung diseases. This group includes autoimmune lung diseases. There are many advantages of plain chest radiography but also significant limitations. It was a revolution in imaging of lung diseases with Computed Tomography (CT), being high resolution an important help in pulmonary interstitium study. This technique has a higher diagnostic accuracy than the conventional chest X-ray both in the detection and the diagnosis of lung diseases, such as autoimmune lung diseases.