Genomic insights into the expansion of carbapenem-resistant Klebsiella pneumoniae within Portuguese hospitals.

Carbapenem-resistant Klebsiella pneumoniae (CR-KP) are a public health concern, causing infections with a high mortality rate, limited therapeutic options and challenging infection control strategies. In Portugal, the CR-KP rate has increased sharply, but the factors associated with this increase are poorly explored. In order to address this question, phylogenetic and resistome analysis were used to compare the draft genomes of 200 CR-KP isolates collected in 2017-2019 from five hospitals in the Lisbon region, Portugal. Most CR-KP belonged to sequence type (ST) 13 (29%), ST17 (15%), ST348 (13%), ST231 (12%) and ST147 (7%). Carbapenem resistance was conferred mostly by the presence of KPC-3 (74%) or OXA-181 (18%), which were associated with IncF/IncN and IncX plasmids, respectively. Almost all isolates were multi-drug resistant, harbouring resistance determinants to aminoglycosides, beta-lactams, trimethoprim, fosfomycin, quinolones and sulphonamides. In addition, 11% of isolates were resistant to colistin. Colonizing and infecting isolates were highly related, and most colonized patients (89%) reported a previous hospitalization. Moreover, among the 171 events of cross-dissemination identified by core genome multi-locus sequence typing data analysis (fewer than five allelic differences), 41 occurred between different hospitals and 130 occurred within the same hospital. The results suggest that CR-KP dissemination in the Lisbon region results from acquisition of carbapenemases in mobile genetic elements, influx of CR-KP into the hospitals by colonized ambulatory patients, and transmission of CR-KP within and between hospitals. Prudent use of carbapenems, patient screening at hospital entry, and improvement of infection control are needed to decrease the burden of CR-KP infection in Portugal.

Feasibility of introducing rejection criteria for stool cultures in a teaching hospital in Portugal.

The possible introduction of rejection criteria for stool cultures (

Malaria diagnosis with the haematology analyser Cell-Dyn 3500: What does the instrument detect?

The Cell-Dyn 3500 instrument could become a sensitive and specific tool in the diagnosis of malaria. The instrument appears to detect malaria-pigment within monocytes and granulocytes. A case of P. vivax malaria in a patient with increased osmotically resistant erythrocytes illustrates the potential of the instrument to detect intraerythrocytic parasites with pigment. However, in most malaria-patients with normal red cell osmotic resistance the observed phenomena seem rather to represent intraleukocytic pigment. This can remain in the circulation of clinically and parasitologically cured individuals and thus may not indicate acute infection. While the instrument can indicate those patients who have been infected a diagnosis of acute malaria must be established independently.

Survey of Klebsiella pneumoniae producing extended-spectrum beta-lactamases at a Portuguese hospital: TEM-10 as the endemic enzyme.

One hundred and thirty-eight isolates of Klebsiella pneumoniae showing resistance to ceftazidime were isolated from different wards of the Hospital de Santa Maria, Lisbon. The genomic DNA of the isolates was analysed by pulsed-field gel electrophoresis (PFGE) and two patterns were predominant. In all isolates the presence of a single large plasmid of about 50 kb suggested that propagation of the outbreak prominently involved plasmid spread. The deduced amino acid sequence indicated the presence of a TEM-10 beta-lactamase. This extended-spectrum beta-lactamase was present among K. pneumoniae isolates, was widely disseminated in different wards and remained persistent as a result of an outbreak involving the dissemination of both the multi-resistance plasmids harbouring the bla gene and the isolates themselves.

[The diversity of Staphylococcus aureus strains isolated in a Lisbon hospital over a 4-year period]. / Diversidade de estirpes de Staphylococcus aureus isoladas num hospital de Lisboa num período de quatro anos.

Over a 4-year period, 2020 Staphylococcus aureus strains isolated in Santa Maria Hospital were studied, 26.3% of which were methicillin-resistant (MRSA). The main specimens from which the strains were isolated included pus, blood and sputum/bronchial secretions. Isolation in blood cultures was the most common source among patients from medical units. Antimicrobial susceptibility studies showed that while in methicillin susceptible strains sensitivity to other antimicrobial agents (apart from penicillin resistance) was the rule, in MRSA strains there was resistance to most antibiotics. Only vancomycin was active against all strains. Phage typing showed that 75.5% of the strains were typable with phages at 100 x R.T.D. Among methicillin sensitive strains, a big diversity of phage patterns was observed, including phage groups I, II, III and V, as well as with phage association D11/95. The large majority of MRSA strains were lysed by group III phages, although several distinct patterns were observed. Within these strains, lysis by groups II and V phages was not observed. Plasmid profiling was the least discriminant issue in the characterization of these micro-organisms because most of the strains harboured only one plasmid (or none). These results showed that a dominant MRSA strain did not exist in this hospital, but rather several distinct strains. The importance, as well as the difficulties in controlling the spread of MRSA strains in the present conditions of high prevalence, are highlighted.

Correlation between consumption of antimicrobials in humans and development of resistance in bacteria.

The correlation between consumption of antimicrobials in humans and the emergence of resistance in bacteria is complex and has proved difficult to establish. Besides antimicrobial use, many other distinct contributing factors are also involved in the issue. Despite this complexity, there is a substantial body of evidence that the use of antibiotics in prophylaxis and in therapy is associated with the development of resistance in the hospital and in the community. Some examples are reviewed, including increase of resistance in enterobacteriaceae, Pseudomonas aeruginosa, Acinetobacter spp., Streptococcus pneumoniae, Staphylococcus aureus, Coagulase Negative Staphylococci and Streptococcus pyogenes after the use of beta-lactam antibiotics, aminoglycosides, fluoroquinolones and macrolides. Success in reversing the rise of resistant strains has been rarely described. Two examples are highlighted, the reduction in the incidence of nasal carriage of penicillin-resistant pneumococci in Icelandic children, and a significant decline in erythromycin resistance in S. pyogenes after the reduction in the use of macrolides in Finland.

[Multicenter study of isolated micro-organisms resistant to antimicrobials in 10 Portuguese hospitals in 1994]. / Estudo multicêntrico de microrganismos isolados e de resistência aos antimicrobianos em dez hospitais Portugueses em 1994.

In 1994, Microbiology Laboratories of ten Portuguese hospitals analysed isolated microorganisms found in blood and urine samples and studied antimicrobial susceptibilities of the most frequent bacterial pathogens. From 63780 blood samples, the most frequent were Staphylococcus spp. and from 69189 urine samples significant numbers of Escherichia coli, Enterococcus spp., Pseudomonas aeruginosa and Candida spp. were isolated. Escherichia coli strains (c.7000) revealed a low percentage of resistance to antibiotics with the exceptions of ampicillin (48%) and co-trimoxazol (25%). Klebsiella pneumoniae isolates (c.2000) revealed important resistance to ampicillin (98%), cephalotin (31%), co-trimoxazol (38%) and gentamicin (28%), while values for 3rd generation cephalosporins varied among hospitals, with several strains showing phenotype of extended-spectrum beta-lactamase. A great variation in resistance values of P. aeruginosa (c.4000) was found in relation to the antibiotics as well as to the hospitals. Resistance to methicillin in S. aureus (c.6000) was high, reaching an average of 47%, and it was even higher with S. epidermidis (c.3000) and S. haemolyticus (c.650). Only vancomycin was always active against these strains. In E. faecalis (c.2500) resistance was of 2% to ampicillin, 35% to gentamicin, 45% to streptomycin and 1% to vancomycin. E. faecium isolates (c.300) showed the most worrying results with 70% resistance to ampicillin, 42% to gentamicin, 59% to streptomycin and 9% (30 strains isolated in 5 hospitals) to vancomycin. Vancomycin resistant strains were also resistant to all other antibiotics.