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1.
Am J Infect Control ; 52(4): 472-478, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37972820

RESUMO

BACKGROUND: While airborne transmission of rhinovirus is recognized in indoor settings, its role in hospital transmission remains unclear. METHODS: We investigated an outbreak of rhinovirus in a pediatric intensive care unit (PICU) to assess air dispersal. We collected clinical, environmental, and air samples, and staff's surgical masks for viral load and phylogenetic analysis. Hand hygiene compliance and the number of air changes per hour in the PICU were measured. A case-control analysis was performed to identify nosocomial rhinovirus risk factors. RESULTS: Between March 31, 2023, and April 2, 2023, three patients acquired rhinovirus in a cubicle (air changes per hour: 14) of 12-bed PICU. A portable air-cleaning unit was placed promptly. Air samples (72,000 L in 6 hours) from the cohort area, and outer surfaces of staff's masks (n = 8), were rhinovirus RNA-negative. Hand hygiene compliance showed no significant differences (31/34, 91.2% vs 33/37, 89.2%, P = 1) before and during outbreak. Only 1 environmental sample (3.8%) was positive (1.86 × 103 copies/mL). Case-control and next-generation sequencing analysis implicated an infected staff member as the source. CONCLUSIONS: Our findings suggest that air dispersal of rhinovirus was not documented in the well-ventilated PICU during the outbreak. Further research is needed to better understand the dynamics of rhinovirus transmission in health care settings.


Assuntos
Surtos de Doenças , Rhinovirus , Criança , Humanos , Rhinovirus/genética , Filogenia , Surtos de Doenças/prevenção & controle , Unidades de Terapia Intensiva Pediátrica
2.
Microorganisms ; 11(10)2023 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-37894094

RESUMO

Staphylococcus argenteus is a novel Staphylococcus species derived from Staphylococcus aureus. Information on the prevalence and genetic characteristics of invasive S. argenteus in Asia is limited. In this study, 275 invasive S. aureus complex strains were retrieved from blood culture specimens in Hong Kong and re-analyzed using MALDI-TOF mass spectrometry and an in-house multiplex real-time PCR for S. argenteus. The prevalence of invasive S. argenteus in Hong Kong was found to be 4.0% (11/275). These strains were primarily susceptible to commonly used antibiotics, except penicillin. Whole-genome sequencing revealed the circulation of three S. argenteus genotypes (ST-2250, ST-1223, and ST-2854) in Hong Kong, with ST-2250 and ST-1223 being the predominant genotypes. The local ST-2250 and ST-1223 strains showed close phylogenetic relationships with isolates from mainland China. Antimicrobial-resistant genes (fosB, tet-38, mepA, blaI, blaZ) could be found in nearly all local S. argenteus strains. The ST-1223 and ST-2250 genotypes carried multiple staphylococcal enterotoxin genes that could cause food poisoning and toxic shock syndrome. The CRISPR/Cas locus was observed only in the ST-2250 strains. This study provides the first report on the molecular epidemiology of invasive S. argenteus in Hong Kong, and further analysis is needed to understand its transmission reservoir.

3.
IEEE J Transl Eng Health Med ; 11: 424-434, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37435542

RESUMO

OBJECTIVE: Infectious diseases are global health challenge, impacted the communities worldwide particularly in the midst of COVID-19 pandemic. The need of rapid and accurate automated systems for detecting pathogens of concern has always been critical. Ideally, such systems shall detect a large panel of pathogens simultaneously regardless of well-equipped facilities and highly trained operators, thus realizing on-site diagnosis for frontline healthcare providers and in critical locations such as borders and airports. METHODS & RESULTS: Avalon Automated Multiplex System, AAMST, is developed to automate a series of biochemistry protocols to detect nucleic acid sequences from multiple pathogens in one test. Automated processes include isolation of nucleic acids from unprocessed samples, reverse transcription and two rounds of amplifications. All procedures are carried out in a microfluidic cartridge performed by a desktop analyzer. The system was validated with reference controls and showed good agreement with their laboratory counterparts. In total 63 clinical samples, 13 positives including those from COVID-19 patients and 50 negative cases were detected, consistent with clinical diagnosis using conventional laboratory methods. CONCLUSIONS: The proposed system has demonstrated promising utility. It would benefit the screening and diagnosis of COVID-19 and other infectious diseases in a simple, rapid and accurate fashion. Clinical and Translational Impact Statement- A rapid and multiplex diagnostic system proposed in this work can clinically help to control spread of COVID-19 and other infectious agents as it can provide timely diagnosis, isolation and treatment to patients. Using the system at remoted clinical sites can facilitate early clinical management and surveillance.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico , Pandemias , Aeroportos , Pessoal de Saúde , Laboratórios
4.
Microbiol Spectr ; 10(3): e0001422, 2022 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-35510851

RESUMO

Pet bite-related infections are commonly caused by the pet's oral flora transmitted to the animal handlers through the bite wounds. In this study, we isolated a streptococcus, HKU75T, in pure culture from the purulent discharge collected from a guinea pig bite wound in a previously healthy young patient. HKU75T was alpha-hemolytic on sheep blood agar and agglutinated with Lancefield group D and group G antisera. API 20 STREP showed that the most likely identity for HKU75T was S. suis I with 85.4% confidence while Vitek 2 showed that HKU75T was unidentifiable. MALDI-TOF MS identified HKU75T as Streptococcus suis (score of 1.86 only). 16S rRNA gene sequencing showed that HKU75T was most closely related to S. parasuis (98.3% nucleotide identity), whereas partial groEL and rpoB gene sequencing showed that it was most closely related to S. suis (81.8% and 89.8% nucleotide identity respectively). Whole genome sequencing and intergenomic distance determined by ANI revealed that there was <85% identity between the genome of HKU75T and those of all other known Streptococcus species. Genome classification using concatenated sequences of 92 bacterial core genes showed that HKU75T belonged to the Suis group. groEL gene sequences identical to that of HKU75T could be directly amplified from the oral cavities of the two guinea pigs owned by the patient. HKU75T is a novel Streptococcus species, which we propose to be named S. oriscaviae. The oral cavity of guinea pigs is presumably a reservoir of S. oriscaviae. Some of the reported S. suis strains isolated from clinical specimens may be S. oriscaviae. IMPORTANCE We reported the discovery of a novel Streptococcus species, propose to be named Streptococcus oriscaviae, from the pus collected from a guinea pig bite wound in a healthy young patient. The bacterium was initially misidentified as S. suis/S. parasuis by biochemical tests, mass spectrometry. and housekeeping genes sequencing. Its novelty was confirmed by whole genome sequencing. Comparative genomic studies showed that S. oriscaviae belongs to the Suis group. S. oriscaviae sequences were detected in the oral cavities of the two guinea pigs owned by the patient, suggesting that the oral cavity of guinea pigs could be a reservoir of S. oriscaviae. Some of the reported S. suis strains may be S. oriscaviae. Further studies are warranted to refine our knowledge on this novel Streptococcus species.


Assuntos
Streptococcus suis , Animais , DNA Bacteriano/genética , Genes Bacterianos , Cobaias , Nucleotídeos , Filogenia , RNA Ribossômico 16S/genética , Streptococcus suis/genética
5.
PLoS Negl Trop Dis ; 16(4): e0010364, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35442979

RESUMO

Although Q fever has been widely reported in the rural areas of China, there is a paucity of data on the epidemiology and clinical characteristics of this disease in large metropolitan cities. In this study, we profile the epidemiology and clinical manifestations of Q fever from a tertiary hospital in Shenzhen, a Southern Chinese metropolitan city with a large immigrant population from other parts of China. A total of 14 patients were confirmed to have Q fever during a nine-year-and-six-month period, five of whom were retrospectively diagnosed during case review or incidentally picked up because of another research project on unexplained fever without localizing features. Some patients had the typical exposure histories and clinical features, while a few other patients had rare manifestations of Q fever, including one with heart failure and diffuse intracapillary proliferative glomerulonephritis, a patient presenting with a spontaneous bacterial peritonitis-like syndrome, and another one with concomitant Q fever and brucellosis. Using a combination of clinical manifestation, inflammatory marker levels, echocardiographic findings and serological or molecular test results, nine, three and two patients were diagnosed to have acute, chronic and convalescent Q fever, respectively. Seven, five and two patients were diagnosed to have Q fever by serological test, nested real-time PCR and next-generation sequencing respectively. Diverse and atypical manifestations are associated with Q fever. The incidence of Q fever is likely to be underestimated. Next-generation sequencing is becoming an important diagnostic modality for culture-negative infections, particularly those that the physicians fail to recognize clinically, such as Q fever.


Assuntos
Coxiella burnetii , Febre Q , Anticorpos Antibacterianos , Cidades , Técnicas de Laboratório Clínico , Coxiella burnetii/genética , Sequenciamento de Nucleotídeos em Larga Escala , Hospitais Urbanos , Humanos , Febre Q/complicações , Febre Q/diagnóstico , Febre Q/epidemiologia , Estudos Retrospectivos
6.
Clin Infect Dis ; 74(8): 1485-1488, 2022 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-34498683

RESUMO

A false-positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse-transcription polymerase chain reaction result can lead to unnecessary public health measures. We report 2 individuals whose respiratory specimens were contaminated by an inactivated SARS-CoV-2 vaccine strain (CoronaVac), likely at vaccination premises. Incidentally, whole genome sequencing of CoronaVac showed adaptive deletions on the spike protein, which do not result in observable changes of antigenicity.


Assuntos
Vacinas contra COVID-19 , COVID-19 , COVID-19/prevenção & controle , Humanos , SARS-CoV-2/genética , Vacinação
7.
Expert Rev Mol Diagn ; 20(12): 1253-1258, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32893699

RESUMO

OBJECTIVES: Accurate assays for hepatitis C virus (HCV) quantitation and genotyping are important for the management of HCV infection. In this study, we evaluated the performance of cobas HCV and cobas HCV GT assays (Roche) for HCV quantitation and genotyping on the cobas 4800 System. METHODS: We compared the performance of the cobas HCV assays with another commercial system (Abbott m2000) using a panel of well-characterized patient samples and proficiency testing samples. RESULTS: The limit-of-detection of the cobas HCV assay in our center was higher (15 IU/mL) than the manufacturer claim (9.2 IU/mL). The assay showed high analytical specificity, accuracy, precision, and linearity. Performance was congruent with the RealTime HCV assay (Abbott). For genotyping, the cobas HCV GT assay only showed moderate agreement with the RealTime HCV Genotype II assay (kappa = 0.550). The cobas assay outperformed the RealTime assay for typing HCV genotypes 1b and 6 (p = 0.033). CONCLUSION: Our results confirm that the cobas 4800 System is a reliable platform for HCV quantitation and genotyping. The cobas HCV GT assay is a good choice for genotype 1b/6 endemic areas in east Asia, clearly outperforming the RealTime HCV Genotype II assay.


Assuntos
Genótipo , Técnicas de Genotipagem , Hepacivirus/genética , Hepatite C/diagnóstico , Hepatite C/virologia , Técnicas de Genotipagem/métodos , Técnicas de Genotipagem/normas , Humanos , RNA Viral , Kit de Reagentes para Diagnóstico , Reação em Cadeia da Polimerase em Tempo Real/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Carga Viral
8.
Emerg Infect Dis ; 26(9): 1987-1997, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32818396

RESUMO

Whether Burkholderia cepacia complex should be an objectionable organism in antiseptic solutions with acceptable total bacterial counts is controversial. By using next-generation sequencing, we documented a polyclonal B. cepacia complex outbreak affecting peritoneal dialysis patients in Hong Kong that was caused by contaminated chlorhexidine solutions. Epidemiologic investigations at a manufacturing site identified a semiautomated packaging machine as the probable source of contamination in some of the brands. Use of whole-genome sequencing differentiated the isolates into 3 brand-specific clonal types. Changes in exit site care recommendations, rapid recall of affected products, and tightening of regulatory control for chlorhexidine-containing skin antiseptics could prevent future similar outbreaks. Environmental opportunistic pathogens, including B. cepacia complex, might be included in regular surveillance as indicator organisms for monitoring environmental contamination.


Assuntos
Infecções por Burkholderia , Complexo Burkholderia cepacia , Infecção Hospitalar , Diálise Peritoneal , Infecções por Burkholderia/epidemiologia , Complexo Burkholderia cepacia/genética , Clorexidina , Infecção Hospitalar/epidemiologia , Surtos de Doenças , Hong Kong , Humanos
9.
Am J Infect Control ; 48(8): 890-896, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32461068

RESUMO

BACKGROUND: To describe the infection control strategy to achieve zero nosocomial transmission of symptomatic coronavirus disease (COVID-19) due to SARS-CoV-2 during the prepandemic phase (the first 72 days after announcement of pneumonia cases in Wuhan) in Hong Kong. METHODS: Administrative support with the aim of zero nosocomial transmission by reducing elective clinical services, decanting wards, mobilizing isolation facilities, providing adequate personal protective equipment, coordinating laboratory network for rapid molecular diagnosis under 4-tier active surveillance for hospitalized patients and outpatients, and organizing staff forum and training was implemented under the framework of preparedness plan in Hospital Authority. The trend of SARS-CoV-2 in the first 72 days was compared with that of SARS-CoV 2003. RESULTS: Up to day 72 of the epidemic, 130 (0.40%) of 32,443 patients being screened confirmed to have SARS-CoV-2 by reverse transcription polymerase chain reaction. Compared with SARS outbreak in 2003, the SARS-CoV-2 case load constituted 8.9% (130 SARS-CoV-2/1458 SARS-CoV) of SARS-CoV infected cases at day 72 of the outbreak. The incidences of nosocomial acquisition of SARS-CoV per 1,000 SARS-patient-day and per 100 SARS-patient-admission were 7.9 and 16.9, respectively, which were significantly higher than the corresponding incidences of SARS-CoV-2 (zero infection, P <.001). CONCLUSIONS: Administrative support to infection control could minimize the risk of nosocomial transmission of SARS-CoV-2.


Assuntos
Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Infecção Hospitalar/epidemiologia , Infecção Hospitalar/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Betacoronavirus/patogenicidade , COVID-19 , Infecções por Coronavirus/transmissão , Infecção Hospitalar/transmissão , Surtos de Doenças/prevenção & controle , Feminino , Hong Kong/epidemiologia , Humanos , Controle de Infecções/métodos , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/transmissão , SARS-CoV-2 , Adulto Jovem
10.
Infect Control Hosp Epidemiol ; 41(5): 493-498, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32131908

RESUMO

OBJECTIVE: To describe the infection control preparedness measures undertaken for coronavirus disease (COVID-19) due to SARS-CoV-2 (previously known as 2019 novel coronavirus) in the first 42 days after announcement of a cluster of pneumonia in China, on December 31, 2019 (day 1) in Hong Kong. METHODS: A bundled approach of active and enhanced laboratory surveillance, early airborne infection isolation, rapid molecular diagnostic testing, and contact tracing for healthcare workers (HCWs) with unprotected exposure in the hospitals was implemented. Epidemiological characteristics of confirmed cases, environmental samples, and air samples were collected and analyzed. RESULTS: From day 1 to day 42, 42 of 1,275 patients (3.3%) fulfilling active (n = 29) and enhanced laboratory surveillance (n = 13) were confirmed to have the SARS-CoV-2 infection. The number of locally acquired case significantly increased from 1 of 13 confirmed cases (7.7%, day 22 to day 32) to 27 of 29 confirmed cases (93.1%, day 33 to day 42; P < .001). Among them, 28 patients (66.6%) came from 8 family clusters. Of 413 HCWs caring for these confirmed cases, 11 (2.7%) had unprotected exposure requiring quarantine for 14 days. None of these was infected, and nosocomial transmission of SARS-CoV-2 was not observed. Environmental surveillance was performed in the room of a patient with viral load of 3.3 × 106 copies/mL (pooled nasopharyngeal and throat swabs) and 5.9 × 106 copies/mL (saliva), respectively. SARS-CoV-2 was identified in 1 of 13 environmental samples (7.7%) but not in 8 air samples collected at a distance of 10 cm from the patient's chin with or without wearing a surgical mask. CONCLUSION: Appropriate hospital infection control measures was able to prevent nosocomial transmission of SARS-CoV-2.


Assuntos
Betacoronavirus , Técnicas de Laboratório Clínico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/prevenção & controle , Controle de Infecções , Pandemias/prevenção & controle , Pneumonia Viral/epidemiologia , Pneumonia Viral/prevenção & controle , COVID-19 , Teste para COVID-19 , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/transmissão , Pessoal de Saúde , Hong Kong , Humanos , Controle de Infecções/métodos , Técnicas de Diagnóstico Molecular , Pneumonia Viral/transmissão , SARS-CoV-2 , Fatores de Tempo
11.
Infect Control Hosp Epidemiol ; 40(12): 1407-1415, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31587686

RESUMO

OBJECTIVE: To report an outbreak of measles with epidemiological link between Hong Kong International Airport (HKIA) and a hospital. METHODS: Epidemiological investigations, patients' measles serology, and phylogenetic analysis of the hemagglutinin (H) and nucleoprotein (N) genes of measles virus isolates were conducted. RESULTS: In total, 29 HKIA staff of diverse ranks and working locations were infected with measles within 1 month. Significantly fewer affected staff had history of travel than non-HKIA-related measles patients [10 of 29 (34.5%) vs 28 of 35 (80%); P < .01]. Of 9 airport staff who could recall detailed exposure history, 6 (66.7%) had visited self-service food premises at HKIA during the incubation period, where food trays, as observed during the epidemiological field investigation, were not washed after use. Furthermore, 1 airport baggage handler who was admitted to hospital A before rash onset infected 2 healthcare workers (HCWs) known to have 2 doses of MMR vaccination with positive measles IgG and lower viral loads in respiratory specimens. Infections in these 2 HCWs warranted contact tracing of another 168 persons (97 patients and 71 HCWs). Phylogenetic comparison of H and N gene sequences confirmed the clonality of outbreak strains. CONCLUSION: Despite good herd immunity with overall seroprevalence of >95% against measles, major outbreaks of measles occurred among HKIA staff having daily contact with many international pssengers. Lessons from severe acute respiratory syndrome (SARS) and measles outbreaks suggested that an airport can be a strategic epidemic center. Pre-exanthem transmission of measles from airport staff to HCWs with secondary vaccine failure poses a grave challenge to hospital infection control.


Assuntos
Aeroportos , Surtos de Doenças/estatística & dados numéricos , Pessoal de Saúde , Imunização Secundária , Vacina contra Sarampo-Caxumba-Rubéola/administração & dosagem , Sarampo/epidemiologia , Adulto , Feminino , Hong Kong/epidemiologia , Humanos , Masculino , Sarampo/prevenção & controle , Vírus do Sarampo , Pessoa de Meia-Idade , Filogenia , Estudos Soroepidemiológicos , Falha de Tratamento
13.
Eur J Clin Microbiol Infect Dis ; 38(3): 563-573, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30680562

RESUMO

We describe a nosocomial outbreak of community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) ST59-SCCmec type V in a neonatal intensive care unit (NICU) in Hong Kong. In-depth epidemiological analysis was performed by whole-genome sequencing (WGS) of the CA-MRSA isolates collected from patients and environment during weekly surveillance and healthcare workers from the later phase of the outbreak. Case-control analysis was performed to analyze potential risk factors for the outbreak. The outbreak occurred from September 2017 to February 2018 involving 15 neonates and one healthcare worker. WGS analysis revealed complicated transmission dynamics between patients, healthcare worker, and environment, from an unrecognized source introduced into the NICU within 6 months before the outbreak. In addition to enforcement of directly observed hand hygiene, environmental disinfection, cohort nursing of colonized and infected patients, together with contact tracing for secondary patients, medical, nursing, and supporting staff were segregated where one team would care for CA-MRSA-confirmed/CA-MRSA-exposed patients and the other for newly admitted patients in the NICU only. Case-control analysis revealed use of cephalosporins [odds ratio 49.84 (3.10-801.46), p = 0.006] and length of hospitalization [odds ratio 1.02 (1.00-1.04), p = 0.013] as significant risk factors for nosocomial acquisition of CA-MRSA in NICU using multivariate analysis. WGS facilitates the understanding of transmission dynamics of an outbreak, providing insights for outbreak prevention.


Assuntos
Infecção Hospitalar/epidemiologia , Surtos de Doenças , Controle de Infecções/métodos , Unidades de Terapia Intensiva Neonatal , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/epidemiologia , Técnicas de Tipagem Bacteriana , Estudos de Casos e Controles , Infecção Hospitalar/microbiologia , Infecção Hospitalar/transmissão , Surtos de Doenças/prevenção & controle , Microbiologia Ambiental , Feminino , Pessoal de Saúde , Hong Kong/epidemiologia , Humanos , Recém-Nascido , Masculino , Staphylococcus aureus Resistente à Meticilina/classificação , Staphylococcus aureus Resistente à Meticilina/genética , Fatores de Risco , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/transmissão , Sequenciamento Completo do Genoma
14.
Mycoses ; 62(5): 450-457, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30597630

RESUMO

Although case series of talaromycosis have been reported in China, their detailed clinical and microbiological characteristics have never been systematically profiled. In this study, we report the clinical characteristics, molecular epidemiology, rapid identification and antifungal susceptibilities of talaromycosis in The University of Hong Kong-Shenzhen Hospital in Shenzhen. Seven cases of talaromycosis were observed since commencement of hospital service in 2012. Three patients were local Shenzhen residents, whereas the other four were immigrants from other parts of China. Two patients were HIV-negative, but with underlying diseases requiring immunosuppressive therapy. Two of the seven patients succumbed. All the seven isolates were successfully identified as T. marneffei by MALDI-TOF MS using Bruker database expanded with in-house generated T. marneffei mass spectra. MLST showed that the seven strains belonged to six different, novel sequences types. Phylogenetic analyses of the concatenated five-locus sequence revealed that the seven strains were scattered amongst other T. marneffei strains. The MICs of itraconazole, isavuconazole, posaconazole and voriconazole against the seven clinical isolates were low but MICs of anidulafungin were high. Underlying diseases other than HIV infection are increasingly important risk factors of talaromycosis. MALDI-TOF MS is useful for rapid identification. Highly diverse T. marneffei sequence types were observed.


Assuntos
Antifúngicos/farmacologia , Técnicas Microbiológicas/métodos , Micoses/epidemiologia , Micoses/patologia , Talaromyces/isolamento & purificação , Adulto , Idoso , Feminino , Genótipo , Hong Kong , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Epidemiologia Molecular , Tipagem de Sequências Multilocus , Técnicas de Tipagem Micológica , Micoses/diagnóstico , Micoses/microbiologia , Estudos Retrospectivos , Fatores de Risco , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Análise de Sobrevida , Talaromyces/classificação , Talaromyces/efeitos dos fármacos , Talaromyces/genética
15.
Int J Syst Evol Microbiol ; 68(11): 3627-3634, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30303475

RESUMO

Five bacterial strains, UAE-HKU57T, UAE-HKU58, UAE-HKU59, UAE-HKU60 and UAE-HKU61, were isolated in Dubai, UAE, from necrotic foot tissue samples of four dromedaries (Camelus dromedarius) and associated maggots (Wohrlfartia species). They were non-sporulating, Gram-negative, non-motile bacilli. They grew well under aerobic conditions at 37 °C, but not anaerobically. The pH range for growth was pH 7.0-9.0 (optimum, pH 7.5-8.0) and the strains could tolerate NaCl concentrations (w/v) up to 2 % (optimum, 0.5 %). They were catalase- and cytochrome oxidase-positive, but caseinase-, gelatinase- and urease-negative. Their phenotypic characters were distinguishable from other closely related species. Phylogenetic analyses of the almost-complete 16S rRNA gene and partial 23S rRNA gene, gyrB, groEL and recA sequences revealed that the five isolates were most closely related to undescribed Ignatzschineria strain F8392 and Ignatzschineria indica, but in most phylogenies clustered separately from these close relatives. Average nucleotide identity analysis showed that genomes of the five isolates (2.47-2.52 Mb, G+C content 41.71-41.86 mol%) were 98.00-99.97% similar to each other, but ≤87.18 % similar to other Ignatzschineriaspecies/strains. Low DNA relatedness between the five isolates to other Ignatzschineriaspecies/strains was also supported by Genome-to-Genome Distance Calculator analysis. The chemotaxonomic traits of the five strains were highly similar. They were non-susceptible (intermediate or resistant) to tetracycline and resistant to trimethoprim/sulphamethoxazole. The name Ignatzschineria cameli sp. nov. is proposed to accommodate these five strains, with strain UAE-HKU57T (=CCOS1165T=NBRC 113042T) as the type strain.


Assuntos
Camelus/microbiologia , Gammaproteobacteria/classificação , Larva/microbiologia , Necrose/microbiologia , Filogenia , Sarcofagídeos/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Pé/microbiologia , Gammaproteobacteria/genética , Gammaproteobacteria/isolamento & purificação , Genes Bacterianos , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/química , Emirados Árabes Unidos
16.
Infect Control Hosp Epidemiol ; 39(10): 1170-1177, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30156177

RESUMO

BACKGROUND: A liver transplant recipient developed hospital-acquired symptomatic hepatitis C virus (HCV) genotype 6a infection 14 months post transplant. OBJECTIVE: Standard outbreak investigation. METHODS: Patient chart review, interviews of patients and staff, observational study of patient care practices, environmental surveillance, blood collection simulation experiments, and phylogenetic study of HCV strains using partial envelope gene sequences (E1-E2) of HCV genotype 6a strains from the suspected source patient, the environment, and the index patient were performed. RESULTS: Investigations and data review revealed no further cases of HCV genotype 6a infection in the transplant unit. However, a suspected source with a high HCV load was identified. HCV genotype 6a was found in a contaminated reusable blood-collection tube holder with barely visible blood and was identified as the only shared item posing risk of transmission to the index case patient. Also, 14 episodes of sequential blood collection from the source patient and the index case patient were noted on the computerized time log of the laboratory barcoding system during their 13 days of cohospitalization in the liver transplant ward. Disinfection of the tube holders was not performed after use between patients. Blood collection simulation experiments showed that HCV and technetium isotope contaminating the tip of the sleeve capping the sleeved-needle can reflux back from the vacuum-specimen tube side to the patient side. CONCLUSIONS: A reusable blood-collection tube holder without disinfection between patients can cause a nosocomial HCV infection. Single-use disposable tube holders should be used according to the recommendations by Occupational Safety and Health Administration and World Health Organization.


Assuntos
Busca de Comunicante , Infecção Hospitalar/transmissão , Contaminação de Equipamentos , Hepacivirus/genética , Hepatite C/transmissão , Transplante de Fígado/efeitos adversos , Infecção Hospitalar/virologia , Feminino , Genótipo , Hepatite C/virologia , Hong Kong , Humanos , Masculino , Prontuários Médicos , Pessoa de Meia-Idade , Filogenia , RNA Viral/genética
17.
Emerg Microbes Infect ; 7(1): 80, 2018 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-29739926

RESUMO

Although Tsukamurella infections have been increasingly reported in Europe, Asia, America, and Africa, indicating that diseases caused by this group of bacteria are emerging in a global scale, species identification within this genus is difficult in most clinical microbiology laboratories. Recently, we showed that groEL gene sequencing is useful for identification of all existing Tsukamurella species. Nevertheless, PCR sequencing is still considered expensive, time-consuming, and technically demanding, and therefore is yet to be incorporated as a routine identification method in clinical laboratories. Using groEL gene sequencing as the reference method, 60 Tsukamurella isolates were identified as five different Tsukamurella species [T. tyrosinosolvens (n = 31), T. pulmonis (n = 25), T. hongkongensis (n = 2), T. strandjordii (n = 1), and T. sinensis (n = 1)]. The most common source of the patient isolates were the eye (n = 18), sputum (n = 6), and blood (n = 6). None of the 60 isolates were identified correctly to species level by MALDI-TOF MS with the original Bruker database V.6.0.0.0. Using the Bruker database extended with 15 type and reference strains which covered all the currently recognized 11 Tsukamurella species, 59 of the 60 isolates were correctly identified to the species level with score ≥2.0. MALDI-TOF MS should be useful for routine species identification of Tsukamurella in clinical microbiology laboratories after optimization of the database. T. tyrosinosolvens was the most common species observed in patients with Tsukamurella infections and the predominant species associated with ocular infections.


Assuntos
Actinobacteria/isolamento & purificação , Técnicas de Tipagem Bacteriana/métodos , Infecções Oculares/microbiologia , Infecções por Bactérias Gram-Positivas/microbiologia , Espectrometria de Massas em Tandem/métodos , Actinobacteria/química , Actinobacteria/classificação , Actinobacteria/genética , Humanos , Filogenia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
18.
J Clin Pathol ; 71(9): 781-786, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29593062

RESUMO

AIMS: Granulomatous mastitis due to Corynebacterium kroppenstedtii is an increasingly recognised cause of an indolent and distressing mastitis in non-lactating females. This slow-growing lipophilic organism is not reliably isolated using routine culture methods. A novel selective culture medium (CKSM) is designed to optimise the isolation of this organism from clinical specimens. METHODS: CKSM contains 10% galactose and Tween 80 (10%) to enhance the growth of C. kroppenstedtii, fosfomycin (100 µg/mL) to suppress the other bacteria, and differentiate C. kroppenstedtii from non-kroppenstedtii lipophilic corynebacteria by esculin hydrolysis. The medium was evaluated for its ability to support the growth of C. kroppenstedtii, selection and differentiation of C. kroppenstedtii from other bacteria in non-sterile clinical specimens. RESULTS: C. kroppenstedtii grew as 1-2 mm colonies with black halo on CKSM within 72 hours of incubation, compared with barely visible pinpoint colonies on routine blood agars. During the four-month period of evaluation with 8896 respiratory specimens, 103 breast specimens, 1903 female genital tract specimens, 617 newborn surface swabs and 10 011 miscellaneous specimens, 186 C. kroppenstedtii were isolated, including 127 (1.4%) respiratory and 59 (0.5%) miscellaneous specimens, 184 of them were found only on CKSM. Besides the three (2.9%) positive breast specimens, 27 (1.4%) high vaginal and endocervical swabs, and 11 (1.8%) surface swabs of newborns were positive for C. kroppenstedtii. CONCLUSIONS: CKSM is a useful addition to routine agar media for the isolation of C. kroppenstedtii, and will be helpful for studying the epidemiology and transmission of this unusual Corynebacterium causing granulomatous mastitis.


Assuntos
Técnicas Bacteriológicas , Infecções por Corynebacterium/diagnóstico , Corynebacterium/isolamento & purificação , Meios de Cultura/química , Mastite Granulomatosa/diagnóstico , Contagem de Colônia Microbiana , Corynebacterium/classificação , Corynebacterium/crescimento & desenvolvimento , Infecções por Corynebacterium/microbiologia , Feminino , Mastite Granulomatosa/microbiologia , Humanos , Fatores de Tempo
19.
Infect Control Hosp Epidemiol ; 39(5): 571-577, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29485019

RESUMO

OBJECTIVEMultidrug-resistant organisms (MDROs) are increasingly reported in residential care homes for the elderly (RCHEs). We assessed whether implementation of directly observed hand hygiene (DOHH) by hand hygiene ambassadors can reduce environmental contamination with MDROs.METHODSFrom July to August 2017, a cluster-randomized controlled study was conducted at 10 RCHEs (5 intervention versus 5 nonintervention controls), where DOHH was performed at two-hourly intervals during daytime, before meals and medication rounds by a one trained nurse in each intervention RCHE. Environmental contamination by MRDOs, such as methicillin-resistant Staphylococcus aureus (MRSA), carbapenem-resistant Acinetobacter species (CRA), and extended-spectrum ß-lactamse (ESBL)-producing Enterobacteriaceae, was evaluated using specimens collected from communal areas at baseline, then twice weekly. The volume of alcohol-based hand rub (ABHR) consumed per resident per week was measured.RESULTSThe overall environmental contamination of communal areas was culture-positive for MRSA in 33 of 100 specimens (33%), CRA in 26 of 100 specimens (26%), and ESBL-producing Enterobacteriaceae in 3 of 100 specimens (3%) in intervention and nonintervention RCHEs at baseline. Serial monitoring of environmental specimens revealed a significant reduction in MRSA (79 of 600 [13.2%] vs 197 of 600 [32.8%]; P<.001) and CRA (56 of 600 [9.3%] vs 94 of 600 [15.7%]; P=.001) contamination in the intervention arm compared with the nonintervention arm during the study period. The volume of ABHR consumed per resident per week was 3 times higher in the intervention arm compared with the baseline (59.3±12.9 mL vs 19.7±12.6 mL; P<.001) and was significantly higher than the nonintervention arm (59.3±12.9 mL vs 23.3±17.2 mL; P=.006).CONCLUSIONSThe direct observation of hand hygiene of residents could reduce environmental contamination by MDROs in RCHEs.Infect Control Hosp Epidemiol 2018;39:571-577.


Assuntos
Infecção Hospitalar/microbiologia , Infecção Hospitalar/prevenção & controle , Desinfecção das Mãos/métodos , Higiene das Mãos/estatística & dados numéricos , Higienizadores de Mão/uso terapêutico , Acinetobacter/isolamento & purificação , Idoso , Idoso de 80 Anos ou mais , Carbapenêmicos , Infecção Hospitalar/epidemiologia , Enterobacteriaceae/isolamento & purificação , Feminino , Fidelidade a Diretrizes , Instituição de Longa Permanência para Idosos , Hong Kong/epidemiologia , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas
20.
Mycopathologia ; 183(3): 615-618, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29349620

RESUMO

Talaromyces marneffei, previously known as Penicillium marneffei, is the most important pathogenic thermally dimorphic fungus causing systemic mycosis in Southeast Asia. Traditionally, T. marneffei infection in human was mainly associated with acquired immunodeficiency syndrome caused by HIV infection. In recent years, there has been an increasing number of T. marneffei infections reported in non-HIV-infected patients with other immunocompromised conditions, including autoantibodies against interferon-gamma, systemic lupus erythematosis, solid organ transplantation, Job's syndrome, hematological malignancies, and use of novel targeted therapies. In this article, we describe the first case of fatal T. marneffei infection in a patient with underlying autoimmune hepatitis, presented as fever without localizing features. The diagnosis of talaromycosis was confirmed with the identification of the fungi isolated from the blood culture specimen by conventional methods and using matrix-assisted laser desorption-ionization time-of-flight mass spectrometer. This case shows the importance of a high index of suspicion, particularly for such a highly fatal but potentially treatable fungal infection.


Assuntos
Sangue/microbiologia , Hepatite Autoimune/complicações , Micoses/diagnóstico , Micoses/patologia , Talaromyces/isolamento & purificação , Idoso , Evolução Fatal , Feminino , Humanos , Técnicas Microbiológicas , Micoses/microbiologia , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
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