RESUMO
A pan-susceptible Salmonella enterica serovar Worthington isolate was detected in the stool of a man returning from Sri Lanka. Under ceftriaxone treatment, a third-generation cephalosporin (3GC)-resistant Salmonella Worthington was isolated after 8 days. Molecular analyses indicated that the two isolates were identical. However, the latter strain acquired a blaDHA-1-carrying IncFII plasmid probably from a Citrobacter amalonaticus isolate colonizing the gut. This is the first report of in vivo acquisition of plasmid-mediated resistance to 3GCs in S. enterica.
Assuntos
Cefalosporinas/farmacologia , Plasmídeos/genética , Salmonella/efeitos dos fármacos , Salmonella/genética , Resistência às Cefalosporinas/genética , Citrobacter/efeitos dos fármacos , Citrobacter/genética , Farmacorresistência Bacteriana Múltipla/genética , Testes de Sensibilidade MicrobianaRESUMO
OBJECTIVES: For low-income countries, data regarding the intestinal colonization with extended-spectrum cephalosporin-resistant (ESC-R) and colistin-resistant (CST-R) Enterobacteriaceae in the community are still scarce. Here, we investigated this phenomenon by analysing hotel employees in Zanzibar. METHODS: During June to July 2018, rectal swabs from 59 volunteers were screened implementing selective enrichments and agar plates. Species identification was achieved using MALDI-TOF MS. Strains were characterized using microdilution panels (MICs), microarray, PCRs for mcr-1/-8, repetitive extragenic palindromic-PCR (rep-PCR) and WGS. RESULTS: Colonization prevalence with ESC-R-, CST-R- and mcr-1-positive Enterobacteriaceae were 91.5%, 66.1% and 18.6%, respectively (average: 2.2 strains per volunteer). Overall, 55 ESC-R Escherichia coli (3 also CST-R), 33 ESC-R Klebsiella pneumoniae (1 also CST-R), 17 CST-R E. coli and 21 CST-R K. pneumoniae were collected. The following main resistance genes were found: ESC-R E. coli (blaCTX-M-15-like, 51.0%), ESC-R K. pneumoniae (blaCTX-M-9-like, 42.9%), CST-R E. coli (mcr-1, 55%) and CST-R K. pneumoniae (D150G substitution in PhoQ). ESBL-producing E. coli mainly belonged to ST361, ST636 and ST131, whereas all those that were mcr-1 positive belonged to ST46 that carried mcr-1 in a 33 kb IncX4 plasmid. ESBL-producing K. pneumoniae mainly belonged to ST17, ST1741 and ST101, whereas CST-R strains belonged to ST11. CONCLUSIONS: We recorded remarkably high colonization prevalence with ESC-R and/or CST-R Enterobacteriaceae in hotel staff. Further research in the local environment, livestock and food chain is warranted to understand this phenomenon. Moreover, as Zanzibar is a frequent holiday destination, attention should be paid to the risk of international travellers becoming colonized and thereby importing life-threatening pathogens into their low-prevalence countries.
Assuntos
Antibacterianos/farmacologia , Cefalosporinas/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/efeitos dos fármacos , Reto/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas Bacteriológicas , Portador Sadio/epidemiologia , Portador Sadio/microbiologia , Enterobacteriaceae/classificação , Enterobacteriaceae/isolamento & purificação , Infecções por Enterobacteriaceae/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prevalência , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Tanzânia/epidemiologia , Adulto JovemRESUMO
BackgroundCarbapenem-resistant Enterobacteriaceae pose a serious threat to public health worldwide, and the role of companion animals as a reservoir is still unclear.AimsThis 4-month prospective observational study evaluated carriage of carbapenem-resistant Enterobacteriaceae at admission and after hospitalisation in a large referral hospital for companion animals in Switzerland.MethodsRectal swabs of dogs and cats expected to be hospitalised for at least 48 h were taken from May to August 2018 and analysed for the presence of carbapenem-resistant Enterobacteriaceae using selective agar plates. Resistant isolates were further characterised analysing whole genome sequences for resistance gene and plasmid identification, and ad hoc core genome multilocus sequence typing.ResultsThis study revealed nosocomial acquisition of Escherichia coli harbouring the carbapenemase gene bla OXA-181, the pAmpC cephalosporinase gene bla CMY-42 as well as quinolone resistance associated with qnrS1 and mutations in the topoisomerases II (GyrA) and IV (ParC). The bla OXA-181 and qnrS1 genes were identified on a 51â¯kb IncX3 plasmid and bla CMY-42 on a 47â¯kb IncI1 plasmid. All isolates belonged to sequence type ST410 and were genetically highly related. This E. coli clone was detected in 17 of 100 dogs and four of 34 cats after hospitalisation (21.6%), only one of the tested animals having tested positive at admission (0.75%). Two positive animals were still carriers 4 months after hospital discharge, but were negative after 6 months.ConclusionsCompanion animals may acquire carbapenemase-producing E. coli during hospitalisation, posing the risk of further dissemination to the animal and human population and to the environment.
Assuntos
Enterobacteriáceas Resistentes a Carbapenêmicos/genética , Infecção Hospitalar/veterinária , Surtos de Doenças/veterinária , Proteínas de Escherichia coli/biossíntese , Escherichia coli/genética , Animais de Estimação/microbiologia , beta-Lactamases/biossíntese , Animais , Derrame de Bactérias , Enterobacteriáceas Resistentes a Carbapenêmicos/isolamento & purificação , Doenças do Gato/epidemiologia , Doenças do Gato/microbiologia , Gatos , Infecção Hospitalar/epidemiologia , Reservatórios de Doenças/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/microbiologia , Cães , Escherichia coli/enzimologia , Escherichia coli/isolamento & purificação , Escherichia coli/fisiologia , Proteínas de Escherichia coli/genética , Feminino , Genoma Bacteriano/genética , Hospitalização , Hospitais Veterinários/estatística & dados numéricos , Masculino , Filogeografia , Plasmídeos/genética , Estudos Prospectivos , Suíça/epidemiologia , beta-Lactamases/genéticaRESUMO
The emergence of the colistin-resistant (COL-R) Enterobacteriaceae represents a worrying health issue. However, only a portion of these strains may carry the plasmid-mediated mcr colistin resistance genes. We evaluated the ability of both ethylenediaminetetraacetic acid (EDTA)-based and dipicolinic acid (DPA)-based broth microdilution (BMD) tests to detect mcr-1 to mcr-5 producers. Of 92 Enterobacteriaceae (85 COL-R), 44 mcr-positive strains (39 Escherichia coli, 3 Klebsiella pneumoniae, and 2 Salmonella spp.) were tested. EDTA (100 µg/mL) was tested in Mueller-Hinton broth (MHB), whereas the DPA (900 µg/mL) was used in cation-adjusted MHB. Results were categorized as positive if in presence of chelator strains exhibited ≥3 two fold MIC decrease compared to the COL MIC alone. The EDTA-based BMD assay detected 41 mcr-positive strains, but 22 false-positive strains (including 12 E. coli and 4 K. pneumoniae) were recorded (sensitivity [SN], 93.2%; specificity [SP], 54.2%). The DPA-based BMD assay detected 37 mcr-positive strains, with 7 false-negative (2 E. coli, 3 K. pneumoniae, 2 Salmonella spp.) strains (SN, 84.1%; SP, 100%). Overall, the EDTA-based BMD assay is not accurate to detect mcr producers, whereas the DPA-based BMD test ("colistin-MAC test") demonstrated good accuracy, but only when implemented for E. coli strains (SN, 94.9%; SP, 100%). With the aim to prevent the dissemination of mcr-possessing E. coli strains, the COL-MAC test could be implemented by clinical laboratories that are unable to perform molecular tests. Moreover, this assay could be applied to screen large collections of isolates to reveal the expression of new mcr-like genes not yet targeted by the current molecular assays.
Assuntos
Proteínas de Bactérias/genética , Ácidos Borônicos/farmacologia , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Ácido Edético/farmacologia , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/genética , Imidazóis/farmacologia , Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/genética , Testes de Sensibilidade Microbiana/métodos , Plasmídeos/genética , Salmonella/efeitos dos fármacos , Salmonella/genéticaRESUMO
We report here the whole-genome sequence of the first extended-spectrum ß-lactamase (ESBL)-producing strain of Salmonella enterica subsp. enterica serovar Napoli, LC0541/17, isolated from the stools of an ambulatory pediatric patient in northern Italy. The strain was of sequence type 474 (ST474) and possessed a 90-kb IncI1 ST49 plasmid carrying the bla CTX-M-1 ESBL gene.
RESUMO
We evaluated several EDTA-based combined-disk tests to detect 25 mcr producers among 48 Enterobacteriaceae. Colistin disks plus EDTA (292/584⯵g) on MH and CAMH agar were used. Results were positive if with chelator there was an inhibition zone increase ≥3â¯mm compared to colistin alone. All tests resulted unreliable (sensitivity ≤68%).