Abstract
Klebsiella pneumoniae
(Kp) bacteria are an increasing threat to public health and represent one of the most concerning pathogens involved in life-threatening infections and antimicrobial ...resistance (AMR). To understand the epidemiology of AMR of Kp in Portugal, we analysed whole genome sequencing, susceptibility testing and other meta data on 509 isolates collected nationwide from 16 hospitals and environmental settings between years 1980 and 2019. Predominant sequence types (STs) included ST15 (n = 161, 32%), ST147 (n = 36, 7%), ST14 (n = 26, 5%) or ST13 (n = 26, 5%), while 31% of isolates belonged to STs with fewer than 10 isolates. AMR testing revealed widespread resistance to aminoglycosides, fluoroquinolones, cephalosporins and carbapenems. The most common carbapenemase gene was
bla
KPC-3
. Whilst the distribution of AMR linked plasmids appears uncorrelated with ST, their frequency has changed over time. Before year 2010, the dominant plasmid group was associated with the extended spectrum beta-lactamase gene
bla
CTX-M-15
, but this group appears to have been displaced by another carrying the
bla
KPC-3
gene. Co-carriage of
bla
CTX-M
and
bla
KPC-3
was uncommon. Our results from the largest genomics study of Kp in Portugal highlight the active transmission of strains with AMR genes and provide a baseline set of variants for future resistance monitoring and epidemiological studies.
According to the EARS-Net surveillance data, Portugal has the highest prevalence of nosocomial methicillin-resistant Staphylococcus aureus (MRSA) in Europe, but the information on MRSA in the ...community is very scarce and the links between the hospital and community are not known. In this study we aimed to understand the events associated to the recent sharp increase in MRSA frequency in Portugal and to evaluate how this has shaped MRSA epidemiology in the community. With this purpose, 180 nosocomial MRSA isolates recovered from infection in two time periods and 14 MRSA isolates recovered from 89 samples of skin and soft tissue infections (SSTI) were analyzed by pulsed-field gel electrophoresis (PFGE), staphylococcal chromosome cassette mec (SCCmec) typing, spa typing and multilocus sequence typing (MLST). All isolates were also screened for the presence of Panton Valentine leukocidin (PVL) and arginine catabolic mobile element (ACME) by PCR. The results showed that ST22-IVh, accounting for 72% of the nosocomial isolates, was the major clone circulating in the hospital in 2010, having replaced two previous dominant clones in 1993, the Iberian (ST247-I) and Portuguese (ST239-III variant) clones. Moreover in 2010, three clones belonging to CC5 (ST105-II, ST125-IVc and ST5-IVc) accounted for 20% of the isolates and may represent the beginning of new waves of MRSA in this hospital. Interestingly, more than half of the MRSA isolates (8/14) causing SSTI in people attending healthcare centers in Portugal belonged to the most predominant clones found in the hospital, namely ST22-IVh (n = 4), ST5-IVc (n = 2) and ST105-II (n = 1). Other clones found included ST5-V (n = 6) and ST8-VI (n = 1). None of the MRSA isolates carried PVL and only five isolates (ST5-V-t179) carried ACME type II. The emergence and spread of EMRSA-15 may be associated to the observed increase in MRSA frequency in the hospital and the consequent spillover of MRSA into the community.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
A 74-year-old woman with diabetes mellitus, chronic renal failure requiring haemodialysis, and peripheral vascular disease conditioning critical limb ischaemia underwent endovascular ...revascularisation and amputation of two gangrenous toes.
is a clinically relevant pathogen and a frequent cause of hospital-acquired (HA) and community-acquired (CA) urinary tract infections (UTI). The increased resistance of this pathogen is leading to ...limited therapeutic options. To investigate the epidemiology, virulence, and antibiotic resistance profile of
in urinary tract infections, we conducted a multicenter retrospective study for a total of 81 isolates (50 CA-UTI and 31 HA-UTI) in Portugal. The detection and characterization of resistance and virulence determinants were performed by molecular methods (PCR, PCR-based replicon typing, and multilocus sequence typing (MLST)). Out of 50 CA-UTI isolates, six (12.0%) carried β-lactamase enzymes, namely
(n = 2),
(n = 1),
(n = 1),
(n = 1), and
(n = 1). All HA-UTI were extended-spectrum β-lactamase (ESBL) producers and had a multidrug resistant profile as compared to the CA-UTI isolates, which were mainly resistant to ciprofloxacin, levofloxacin, tigecycline, and fosfomycin. In conclusion, in contrast to community-acquired isolates, there is an overlap between virulence and multidrug resistance for hospital-acquired UTI
pathogens. The study is the first to report different virulence characteristics for hospital and community
pathogens, despite the production of β-lactamase and even with the presence of CTX-M-15 ESBL, a successful international ST15 clone, which were identified in both settings. This highlights that a focus on genomic surveillance should remain a priority in the hospital environment.
•Resistance to colistin is mediated by distinct and complex mechanisms•Analysis of 22 colistin resistance-associated genes performed for 140 isolates•mgrB disruption was the most frequent mechanism ...associated with colistin resistance•Phylogenomic analysis enabled the identification of clade-specific variants
The emergence of carbapenemase-producing Klebsiella pneumoniae strains has triggered the use of old antibiotics such as colistin. This is driving the emergence of colistin resistance in multidrug-resistant strains that underlie life-threatening infections. This study analyses the mutational diversity of 22 genes associated with colistin resistance in 140 K. pneumoniae clinical isolates integrated in a high-resolution phylogenetic scenario. Colistin susceptibility was accessed by broth microdilution. A total of 98 isolates were susceptible and 16 were resistant, 10 of which were carbapenemase producers. Across the 22 genes examined, 171 non-synonymous mutations and 9 mutations associated with promoter regions were found. Eighty-five isolates had a truncation and/or deletion in at least one of the 22 genes. However, only seven mutations, the complete deletion of mgrB or insertion sequence (IS)-mediated disruption, were exclusively observed in resistant isolates. Four of these (mgrBIle13fs, pmrBGly207Asp, phoQHis339Asp and ramAIle28Met) comprised novel mutations that are potentially involved in colistin resistance. One strain bore a ISEcp1-blaCTX-M-15::mgrB disruption, underlying co-resistance to third-generation cephalosporins and colistin. Moreover, the high-resolution phylogenetic context shows that most of the mutational diversity spans multiple phylogenetic clades, and most of the mutations previously associated with colistin resistance are clade-associated and present in susceptible isolates, showing no correlation with colistin resistance.
In conclusion, the present study provides relevant data on the genetic background of genes involved with colistin resistance deeply rooted across monophyletic groups and provides a better understanding of the genes and mutations involved in colistin resistance.
Sífilis: Prevalência num Hospital de Lisboa Lopes, Leonor; Ferro-Rodrigues, Rita; Llobet, Samuel ...
Acta médica portuguesa,
01/2016, Letnik:
29, Številka:
1
Journal Article
Odprti dostop
Introdução: A sífilis é uma doença de transmissão sexual e vertical. A sua incidência está a aumentar na Europa, particularmente em Portugal.Material e Métodos: Estudo retrospetivo baseado na análise ...laboratorial de testes treponémicos positivos, entre janeiro e dezembro de 2013, no Hospital de Santa Maria. Foram incluídos doentes internados, da consulta externa, do hospital dia e da urgência. Procedeu-se a caraterização epidemiológica, classificação da doença e de fatores de risco associados.Resultados: Obteve-se uma amostra de 484 doentes, após exclusão de 51 por ausência de dados clínicos nos processos e de 45 por valores falsos positivos. Verificou-se predomínio do sexo masculino (75%) e idade média de 47 anos. A maioria (59%) tinha testes serológicos compatíveis com sífilis no passado e 3,7% encontrava-se em vigilância clínica. Diagnosticou-se sífilis primária em 13doentes, secundária em 71, latente precoce em 40, latente indeterminada em 49 e latente tardia em cinco. No grupo sífilis recente, 42% (n = 124) eram seropositivos para o VIH e 8% tiveram, em simultâneo, este diagnóstico.Discussão: Salienta-se a elevada prevalência da coinfeção pelo VIH nos doentes com sífilis recente, reforçando a importância de promover a utilização de medidas preventivas. Registaram-se 11% de formas clínicas tardias, que são de notificação obrigatória desde junho de 2014. Todos os testes serológicos para o diagnóstico de sífilis apresentam limitações, o que enfatiza a importância da correlação clínico-laboratorial.Conclusão: A sífilis continua a ser um problema de saúde pública pelo que é necessário estabelecer programas de educação, rastreio e follow-up para reduzir a sua prevalência e tornar mais eficiente o rastreio dos parceiros.
The carbapenem-resistant Enterobacterales (CRE) strains have been identified by the World Health Organization as critical priority pathogens in research and development of diagnostics, treatments, ...and vaccines. However, recent molecular information about carbapenem-resistant
(CRK) epidemiology in Portugal is still scarce. Thus, this study aimed to provide the molecular epidemiology, resistome, and virulome of CRK clinical strains recovered from a tertiary care hospital centre (2019-2021) using polymerase chain reaction (PCR) and the advanced molecular technique whole-genome sequencing (WGS). PCR amplification of carbapenemase genes was performed in 437 carbapenem-resistant
strains. The most frequent carbapenemases were: KPC-3 (42%), followed by OXA-181 (20%), GES-5 (0.2%), and NDM-1 (0.2%). Additionally, 10 strains (2%) coproduced KPC-3 and OXA-181, and 1 strain coproduced KPC-3 and OXA-48 (0.2%). The genomic population structure of 68 strains characterized by WGS demonstrated the ongoing dissemination of four main high-risk clones: ST13, ST17, ST147, and ST307, while no clones belonging to the European predominant clonal groups (CG15 and CG258) were found. Moreover, we describe one
ST39-KL62 that coproduced the NDM-1 carbapenemase and the extended-spectrum beta-lactamase CTX-M-15, and one
ST29-KL54 GES-5 and BEL-1 coproducer. Furthermore, a high prevalence of iron siderophores were present in all CRK strains, with several strains presenting both colibactin and the hypermucoviscosity phenotype. Thus, the data presented here highlight an uncommon molecular epidemiology pattern in Portugal when compared with most European countries, further supporting the emergence and dissemination of nonclonal group 258 hypervirulent multidrug high-risk clones and the need to promote in-depth hospital molecular surveillance studies.
The combination of ceftazidime/avibactam (CZA) is a novel β-lactam/β-lactamase inhibitor with activity against
carbapenemase (KPC)-producing Enterobacterales. Emerging cases caused by CZA-resistant ...strains that produce variants of KPC genes have already been reported worldwide. However, to the best of our knowledge, no CZA-resistant strains were reported in Portugal. In September 2019, a
CZA-resistant strain was collected from ascitic fluid at a surgery ward of a tertiary University Hospital Center in Lisboa, Portugal. The strain was resistant to ceftazidime/avibactam, as well as to ceftazidime, cefoxitin, gentamicin, amoxicillin/clavulanic acid, and ertapenem, being susceptible to imipenem and tigecycline. A hypermucoviscosity phenotype was confirmed by string test. Whole-genome sequencing (WGS) analysis revealed the presence of an ST13 KPC70-producing
, a KPC-3 variant, differing in two amino-acid substitutions (D179Y and T263A). The D179Y mutation in the KPC Ω-loop region is the most common amino-acid substitution in KPC-2 and KPC-3, further leading to CZA resistance. The second mutation causes a KPC-70 variant in which threonine replaces alanine (T263A). The CZA-resistant strain showed the capsular locus KL3 and antigen locus O1v2. Other important virulence factors were identified: fimbrial adhesins type 1 and type 3, as well as the cluster of iron uptake systems aerobactin, enterobactin, salmochelin, and yersiniabactin included in integrative conjugative element 10 (ICE
) with the genotoxin colibactin cluster. Herein, we report the molecular characterization of the first hypervirulent CZA-resistant ST13 KPC-70-producing
strain in Portugal. The emergence of CZA-resistant strains might pose a serious threat to public health and suggests an urgent need for enhanced clinical awareness and epidemiologic surveillance.
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