RESUMO
Hospital-acquired infections are on the rise and are a substantial cause of clinical and financial burden for healthcare systems. While infection control plays a major role in curtailing the spread of outbreak organisms, it is not always successful. One organism of particular concern is Acinetobacter baumannii, due to both its persistence in the hospital setting and its ability to acquire antibiotic resistance. A. baumannii has emerged as a nosocomial pathogen that exhibits high levels of resistance to antibiotics, and remains resilient against traditional cleaning measures with resistance to Colistin increasingly reported. Given the magnitude and costs associated with hospital acquired infections, and the increase in multidrug-resistant organisms, it is worth re-evaluating our current approaches and looking for alternatives or adjuncts to traditional antibiotics therapies. The aims of this review are to look at how this organism is spread within the hospital setting, discuss current treatment modalities, and propose alternative methods of outbreak management.
RESUMO
Otitis externa is the inflammation of the external auditory canal. The disease is common and shows a seasonal variation with a greater incidence in warmer months. Pseudomonas aeruginosa is a common pathogen in otitis externa and in this retrospective study, we show a corresponding seasonal variation in the proportional incidence of P. aeruginosa isolates from otitis externa in South East England. In total 7770 patients were diagnosed with otitis externa over a period of 9 years from January 2008 to December 2016. P. aeruginosa was isolated from 2802 patients (proportional incidence of 36%). Incidence was higher in the months of August, September and October and in patients between 5 and 15 years of age. We postulate a combination of increased contact with water during warm weather in the holiday season and increased rainfall in the preceding season as a putative mechanism for the seasonal trends.
Assuntos
Otite Externa/epidemiologia , Infecções por Pseudomonas/epidemiologia , Pseudomonas aeruginosa/isolamento & purificação , Adolescente , Criança , Pré-Escolar , Inglaterra/epidemiologia , Humanos , Incidência , Otite Externa/microbiologia , Infecções por Pseudomonas/microbiologia , Estudos Retrospectivos , Estações do AnoRESUMO
The DNA sequence flanking a tet(W) gene in an oral Rothia sp. was determined. The gene was linked to two different transposases, and these were flanked by two almost identical mef (macrolide efflux) genes. This structure was found in 4 out of 20 tet(W)-containing oral bacteria investigated.
Assuntos
Proteínas de Bactérias/genética , Micrococcaceae/efeitos dos fármacos , Micrococcaceae/genética , Boca/microbiologia , Resistência a Tetraciclina/genética , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Elementos de DNA Transponíveis , Humanos , Proteínas de Membrana , Tetraciclina/farmacologia , Transposases/genéticaRESUMO
We determined the prevalence of erythromycin-resistant bacteria in the oral cavity and identified mef and erm(B) as the most common resistance determinants. In addition, we demonstrate the genetic linkage, on various Tn1545-like conjugative transposons, between erythromycin and tetracycline resistance in a number of isolates.
Assuntos
Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Eritromicina/farmacologia , Boca/microbiologia , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Southern Blotting , Elementos de DNA Transponíveis/genética , Proteínas de Ligação a DNA/genética , Farmacorresistência Bacteriana , Humanos , Testes de Sensibilidade Microbiana , Plasmídeos/genética , Proteínas Metiltransferases/genética , Resistência a Tetraciclina , Fatores de Transcrição/genéticaRESUMO
A major drawback of most studies on how bacteria become resistant to antibiotics is that they concentrate mainly on bacteria that can be cultivated in the laboratory. In the present study, we cloned part of the oral metagenome and isolated a novel tetracycline resistance gene, tet(37), which inactivates tetracycline.
Assuntos
Bactérias/efeitos dos fármacos , Placa Dentária/microbiologia , Genoma Bacteriano , Saliva/microbiologia , Resistência a Tetraciclina/genética , Adulto , Sequência de Aminoácidos , Bactérias/genética , Humanos , Dados de Sequência MolecularRESUMO
Tetracycline is a broad-spectrum antibiotic used in humans, animals, and aquaculture; therefore, many bacteria from different ecosystems are exposed to this antibiotic. In order to determine the genetic basis for resistance to tetracycline in bacteria from the oral cavity, saliva and dental plaque samples were obtained from 20 healthy adults who had not taken antibiotics during the previous 3 months. The samples were screened for the presence of bacteria resistant to tetracycline, and the tetracycline resistance genes in these isolates were identified by multiplex PCR and DNA sequencing. Tetracycline-resistant bacteria constituted an average of 11% of the total cultivable oral microflora. A representative 105 tetracycline-resistant isolates from the 20 samples were investigated; most of the isolates carried tetracycline resistance genes encoding a ribosomal protection protein. The most common tet gene identified was tet(M), which was found in 79% of all the isolates. The second most common gene identified was tet(W), which was found in 21% of all the isolates, followed by tet(O) and tet(Q) (10.5 and 9.5% of the isolates, respectively) and then tet(S) (2.8% of the isolates). Tetracycline resistance genes encoding an efflux protein were detected in 4.8% of all the tetracycline-resistant isolates; 2.8% of the isolates had tet(L) and 1% carried tet(A) and tet(K) each. The results have shown that a variety of tetracycline resistance genes are present in the oral microflora of healthy adults. This is the first report of tet(W) in oral bacteria and the first report to show that tet(O), tet(Q), tet(A), and tet(S) can be found in some oral species.