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1.
J Clin Microbiol ; 60(1): e0161021, 2022 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-34705536

RESUMO

The carbapenem/beta-lactamase inhibitor meropenem-vaborbactam (MEV) used to treat complicated urinary tract infections and pyelonephritis in adults was approved in 2017 by the U.S. Food and Drug Administration (FDA). Here, we evaluated Vitek 2 MEV (bioMérieux, Durham, NC) compared to the reference broth microdilution (BMD) method. Of 449 Enterobacterales isolates analyzed per FDA/CLSI breakpoints, the overall performance was 98.2% essential agreement (EA), 98.7% category agreement (CA), and 0% very major errors (VME) or major errors (ME). For 438 FDA intended-for-use Enterobacterales isolates, performance was 98.2% EA, 98.6% CA, and 0% VME or ME. Evaluable EA was 81.0%, but with only 42 on-scale evaluable results. Individual species demonstrated EA and CA rates of ≥90% without any VME or ME. When evaluated using European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, overall Vitek 2 MEV performance for Enterobacterales and Pseudomonas aeruginosa demonstrated 97.3% EA, 99.2% CA, 2.3% VME, and 0.6% ME (after error resolution: 97.3% EA, 99.4% CA, 2.2% VME, and 0.4% ME) compared to the reference BMD method. Performance for P. aeruginosa included 92.2% EA, 97.4% CA, 0% VME, and 3.0% ME (after error resolution: 92.2% EA, 98.7% CA, 0% VME, and 1.5% ME). Performance for Enterobacterales included 98.2% EA, 99.6% CA, 3.0% VME, and 0.2% ME. Evaluable EA was 80.6% but was based on only 67 evaluable results. These findings support Vitek 2 MEV as an accurate automated system for MEV susceptibility testing of Enterobacterales and P. aeruginosa and could be an alternate solution to the manual-labor-intensive reference BMD method.


Assuntos
Antibacterianos , Pseudomonas aeruginosa , Antibacterianos/farmacologia , Ácidos Borônicos , Humanos , Meropeném/farmacologia , Testes de Sensibilidade Microbiana
2.
Eur J Clin Microbiol Infect Dis ; 40(9): 1909-1917, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33837878

RESUMO

The use of matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry has proven to be rapid and accurate for the majority of clinical isolates. Some gaps remain concerning rare, emerging, or highly pathogenic species, showing the need to continuously expand the databases. In this multicenter study, we evaluated the accuracy of the VITEK MS v3.2 database in identifying 1172 unique isolates compared to identification by DNA sequence analysis. A total of 93.6% of the isolates were identified to species or group/complex level. A remaining 5.2% of the isolates were identified to the genus level. Forty tests gave a result of no identification (0.9%) and 12 tests (0.3%) gave a discordant identification compared to the reference identification. VITEK MS is also the first MALDI-TOF MS system that is able to delineate the four members of the Acinetobacter baumannii complex at species level without any specific protocol or special analysis method. These findings demonstrate that the VITEK MS v3.2 database is highly accurate for the identification of bacteria and fungi encountered in the clinical laboratory as well as emerging species like Candida auris and the highly pathogenic Brucella species.


Assuntos
Bactérias/isolamento & purificação , Brucella/isolamento & purificação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/instrumentação , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/normas , Leveduras/isolamento & purificação , Bactérias/química , Bactérias/classificação , Brucella/química , Brucella/classificação , Brucella/patogenicidade , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , Leveduras/química , Leveduras/classificação
3.
Antimicrob Agents Chemother ; 59(2): 1020-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25451057

RESUMO

Pseudomonas aeruginosa is a notoriously difficult-to-treat pathogen that is a common cause of severe nosocomial infections. Investigating a collection of ß-lactam-resistant P. aeruginosa clinical isolates from a decade ago, we uncovered resistance to ceftazidime-avibactam, a novel ß-lactam/ß-lactamase inhibitor combination. The isolates were systematically analyzed through a variety of genetic, biochemical, genomic, and microbiological methods to understand how resistance manifests to a unique drug combination that is not yet clinically released. We discovered that avibactam was able to inactivate different AmpC ß-lactamase enzymes and that blaPDC regulatory elements and penicillin-binding protein differences did not contribute in a major way to resistance. By using carefully selected combinations of antimicrobial agents, we deduced that the greatest barrier to ceftazidime-avibactam is membrane permeability and drug efflux. To overcome the constellation of resistance determinants, we show that a combination of antimicrobial agents (ceftazidime/avibactam/fosfomycin) targeting multiple cell wall synthetic pathways can restore susceptibility. In P. aeruginosa, efflux, as a general mechanism of resistance, may pose the greatest challenge to future antibiotic development. Our unexpected findings create concern that even the development of antimicrobial agents targeted for the treatment of multidrug-resistant bacteria may encounter clinically important resistance. Antibiotic therapy in the future must consider these factors.


Assuntos
Antibacterianos/farmacologia , Compostos Azabicíclicos/farmacologia , Ceftazidima/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Fosfomicina/farmacologia , Bactérias Gram-Negativas , Humanos , Testes de Sensibilidade Microbiana
4.
Aesthetic Plast Surg ; 39(4): 597-601, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26044395

RESUMO

INTRODUCTION: Refrigerant sprays have been used for pain relief at the time of minor office procedures. However, their sterility remains in question. This study investigates the microbiologic effect of this vapocoolant when sprayed after 70 % isopropyl alcohol skin preparation. MATERIALS AND METHODS: In 50 healthy volunteers, three skin culture samples were collected: Group 1 prior to alcohol application; Group 2 after preparation with alcohol, and Group 3 after preparation with alcohol followed with vapocoolant spray. Samples were cultured in a blinded fashion and analyzed after 5 days of incubation. Gram staining was performed when cultures were positive. RESULTS: Bacterial growth was found in 98 % of samples prior to any skin preparation. This was reduced to 54 % after alcohol use (Group 2). Spraying with the skin refrigerant further reduced bacterial growth to 46 % (Group 3). The results showed a significant reduction in the number of positive bacterial cultures following skin preparation with alcohol and when alcohol prep was followed by vapocoolant spray (p < 0.001) compared to initial cultures. No statistical difference was observed between Groups 2 and 3 (p = 0.74). CONCLUSIONS: The use of the vapocoolant spray does not compromise the sterility of the skin following alcohol prep. Both 70 % isopropyl alcohol antiseptic preparation and skin preparation followed by vapocoolant spray significantly reduce skin colonization when compared to unprepared skin (p < 0.001).


Assuntos
Pele , Esterilização/métodos , Adulto , Bactérias/isolamento & purificação , Temperatura Baixa , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nebulizadores e Vaporizadores , Estudos Prospectivos , Pele/microbiologia , Adulto Jovem
5.
J Clin Microbiol ; 51(7): 2072-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23596240

RESUMO

Rapid identification of pathogens from blood cultures can decrease lengths of stay and improve patient outcomes. We evaluated the accuracy of the Verigene Gram-positive blood culture (BC-GP) nucleic acid test for investigational use only (Nanosphere, Inc., Northbrook, IL) for the identification of Gram-positive bacteria from blood cultures. The detection of resistance genes (mecA in Staphylococcus aureus and Staphylococcus epidermidis and vanA or vanB in Enterococcus faecium and Enterococcus faecalis) by the BC-GP assay also was assessed. A total of 186 positive blood cultures (in BacT/Alert FA bottles) with Gram-positive cocci observed with Gram staining were analyzed using the BC-GP assay. The BC-GP results were compared with the identification and susceptibility profiles obtained with routine methods in the clinical laboratory. Discordant results were arbitrated with additional biochemical, cefoxitin disk, and repeat BC-GP testing. The initial BC-GP organism identification was concordant with routine method results for 94.6% of the blood cultures. Only 40% of the Streptococcus pneumoniae identifications were correct. The detection of the mecA gene for 69 blood cultures with only S. aureus or S. epidermidis was concordant with susceptibility testing results. For 3 of 6 cultures with multiple Staphylococcus spp., mecA detection was reported but was correlated with oxacillin resistance in a species other than S. aureus or S. epidermidis. The detection of vanA agreed with susceptibility testing results for 45 of 46 cultures with E. faecalis or E. faecium. Comparison of the mean times to results for each organism group showed that BC-GP results were available 31 to 42 h earlier than phenotypic identifications and 41 to 50 h earlier than susceptibility results.


Assuntos
Bacteriemia/diagnóstico , Bacteriemia/microbiologia , Técnicas Bacteriológicas/métodos , Farmacorresistência Bacteriana , Bactérias Gram-Positivas/classificação , Bactérias Gram-Positivas/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Bactérias Gram-Positivas/genética , Humanos , Fatores de Tempo
6.
J Clin Microbiol ; 50(1): 138-41, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22031703

RESUMO

To investigate the performance of a nucleic acid amplification test (NAAT) for the diagnosis of Mycobacterium tuberculosis bacteremia, 5-ml aliquots of blood were inoculated into bioMérieux mycobacterial (MB) bottles and incubated, and 5-ml aliquots of blood were extracted and tested by real-time PCR. Of 25 samples from patients with M. tuberculosis bacteremia, 9 (36.0%) were positive and 1 (1.5%) of 66 control samples was positive by NAAT. The NAAT shows promise, but modifications should focus on improving sensitivity.


Assuntos
Bacteriemia/diagnóstico , Técnicas Bacteriológicas/métodos , Sangue/microbiologia , Mycobacterium tuberculosis/isolamento & purificação , Reação em Cadeia da Polimerase em Tempo Real/métodos , Manejo de Espécimes/métodos , Tuberculose/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Bacteriemia/microbiologia , Humanos , Pessoa de Meia-Idade , Mycobacterium tuberculosis/genética , Sensibilidade e Especificidade , Tuberculose/microbiologia , Adulto Jovem
7.
Am J Clin Pathol ; 155(4): 522-526, 2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33399200

RESUMO

OBJECTIVES: Pool testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) preserves testing resources at the risk of missing specimens through specimen dilution. METHODS: To determine whether SARS-CoV-2 specimens would be missed after 10:1 pooling, we identified 10 specimens with midrange (ie, 25-34 cycles) and 10 with late (ie, >34-45 cycles) crossing threshold (Ct) values and tested these both neat and after 10:1 pooling. Final test results and Ct changes were compared. RESULTS: Overall, 17 of 20 specimens that contained SARS-CoV-2 were detected after 10:1 pooling with the Xpert Xpress SARS-CoV-2 Assay (Cepheid), rendering an 85% positive percentage of agreement. All 10 of 10 specimens with an undiluted Ct in the mid-Ct range were detected after 10:1 pooling, in contrast to 7 of 10 with an undiluted Ct in the late-Ct range. The overall Ct difference between the neat testing and the 10:1 pool was 2.9 cycles for the N2 gene target and 3 cycles for the E gene target. The N2 gene reaction was more sensitive than the E gene reaction, detecting 16 of 20 positive specimens after 10:1 pooling compared with 9 of 20 specimens. CONCLUSIONS: An 85% positive percentage of agreement was achieved, with only specimens with low viral loads being missed following 10:1 pooling. The average impact on both reverse transcription polymerase chain reactions within this assay was about 3 cycles.


Assuntos
Infecções Assintomáticas , Teste de Ácido Nucleico para COVID-19/métodos , COVID-19/diagnóstico , Manejo de Espécimes/métodos , COVID-19/virologia , Reações Falso-Negativas , Estudos de Viabilidade , Humanos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Carga Viral
8.
J Clin Microbiol ; 47(12): 3985-90, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19846642

RESUMO

After isoniazid and rifampin (rifampicin), the next pivotal drug class in Mycobacterium tuberculosis treatment is the fluoroquinolone class. Mutations in resistance-determining regions (RDR) of the rpoB, katG, and gyrA genes occur with frequencies of 97%, 50%, and 85% among M. tuberculosis isolates resistant to rifampin, isoniazid, and fluoroquinolones, respectively. Sequences are highly conserved, and certain mutations correlate well with phenotypic resistance. We developed a pyrosequencing assay to determine M. tuberculosis genotypic resistance to rifampin, isoniazid, and fluoroquinolones. We characterized 102 M. tuberculosis clinical isolates from the Philippines for susceptibility to rifampin, isoniazid, and ofloxacin by using the conventional submerged-disk proportion method and validated our pyrosequencing assay using these isolates. DNA was extracted and amplified by using PCR primers directed toward the RDR of the rpoB, katG, and gyrA genes, and pyrosequencing was performed on the extracts. The M. tuberculosis H37Rv strain (ATCC 25618) was used as the reference strain. The sensitivities and specificities of pyrosequencing were 96.7% and 97.3%, 63.8% and 100%, and 70.0% and 100% for the detection of resistance to rifampin, isoniazid, and ofloxacin, respectively. Pyrosequencing is thus a rapid and accurate method for detecting M. tuberculosis resistance to these three drugs.


Assuntos
Antituberculosos/farmacologia , Farmacorresistência Bacteriana , Isoniazida/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Ofloxacino/farmacologia , Rifampina/farmacologia , Análise de Sequência de DNA/métodos , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/genética , Fluoroquinolonas/farmacologia , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Mutação , Mycobacterium tuberculosis/genética , Fenótipo , Fatores de Tempo
9.
Clin Orthop Relat Res ; 467(5): 1360-4, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-18989729

RESUMO

Bacteria such as staphylococci commonly encountered in orthopaedic infections form biofilms and adhere to bone implants and cements. Various methods to disrupt the biofilm and enhance bacterial detection have been reported. We will describe the effectiveness of vortexing and sonication to improve the detection of biofilm-formative bacteria from polymethylmethacrylate by conventional quantitative bacterial culture and real-time quantitative PCR. We used a single biofilm-formative Staphylococcus aureus strain and 20 polymethylmethacrylate coupons as an in vitro biofilm model; four coupons were used for each of two control groups or three experimental sonication times (1, 5, and 30 minutes). Vortexing the cement without sonication increased the yield of adherent bacteria to a considerable extent. The combination of vortexing and sonication further enhanced the yield regardless of the duration of sonication. Quantitative conventional cultures correlated with quantitative PCR assay. The combination of vortexing and sonication to disrupt the bacterial biofilm followed by quantitative PCR and/or culture seems to be a sensitive method for detecting bacteria adherent to bone cement.


Assuntos
Técnicas de Tipagem Bacteriana , Biofilmes , Cimentos Ósseos/análise , Polimetil Metacrilato/análise , Sonicação , Staphylococcus aureus/isolamento & purificação , Aderência Bacteriana , Contagem de Colônia Microbiana , Projetos Piloto , Reação em Cadeia da Polimerase , Ribotipagem , Staphylococcus aureus/classificação , Staphylococcus aureus/genética , Staphylococcus aureus/crescimento & desenvolvimento , Fatores de Tempo
10.
Am J Clin Pathol ; 130(2): 284-9, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18628099

RESUMO

Salmonella and Shigella species are routinely sought in stool specimens submitted for culture. It is a common practice to screen lactose-negative colonies by using triple sugar iron agar, lysine iron agar, and Christensen urea agar to determine if further identification is necessary. We designed and evaluated a novel combination of media, which are layered in a single tube, for screening isolates suspected to possibly represent Salmonella or Shigella. We tested this media combination with 106 Salmonella, 56 Shigella, and 56 other gram-negative bacilli. All Salmonella and Shigella isolates tested were appropriately characterized as possible Salmonella or Shigella by using an algorithm developed for use with this media combination. Similarly, 53 (95%) of 56 other gram-negative bacilli were appropriately screened as non -Salmonella and non -Shigella isolates. This unique media combination provides the most important biochemical reactions needed to screen for Salmonella and Shigella in a single-tube format, which decreases labor by two thirds (ie, 1 tube is inoculated vs 3).


Assuntos
Técnicas Bacteriológicas , Meios de Cultura , Salmonella/isolamento & purificação , Shigella/isolamento & purificação , Ágar , Algoritmos , Bactérias Aeróbias Gram-Negativas/isolamento & purificação
11.
Cerebrospinal Fluid Res ; 5: 17, 2008 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-18950490

RESUMO

BACKGROUND: Detailed human studies of the mechanisms and development of shunt infection in real time are not possible, and we have developed a canine hydrocephalus model to overcome this. The intention of this pilot study was to show that the canine hydrocephalus model could be shunted using conventional "human" shunts, and that a shunt infection could be established so that further studies could then be planned. METHODS: Hydrocephalus was induced in seven dogs (Canis familiaris) by fourth ventricle obstruction. Four weeks later they were shunted using a Hakim Precision valve. Four of the dogs received shunts whose ventricular catheter had been inoculated with Staphylococcus epidermidis, and three were uninoculated controls. Four weeks after shunting the dogs were sacrificed and necropsy was performed. Removed shunts and tissue samples were examined microbiologically and isolates were subjected to detailed identification and genomic comparison. RESULTS: All the dogs remained well after shunting. Examination of removed shunt components revealed S. epidermidis in the brain and throughout the shunt system in the four inoculated animals, but in two of these Staphylococcus intermedius was also found. S. intermedius was also isolated from all three "negative" controls. There were slight differences between S. intermedius strains suggesting endogenous infection rather than cross- infection from a point source. CONCLUSION: Shunt infection was established in the canine model, and had the experiment been extended beyond four weeks the typical microbiological, pathological and clinical features might have appeared. The occurrence of unplanned shunt infections in control animals due to canine normal skin flora reflects human clinical experience and underlines the usual source of bacteria causing shunt infection.

12.
Diagn Microbiol Infect Dis ; 58(3): 315-23, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17382507

RESUMO

To rapidly identify Mycobacterium and Nocardia spp. without costly probes, we had implemented capillary electrophoresis (CE) in polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis to analyze their 65-kDa heat shock protein (hsp65) gene. The PCR-RFLP analysis with CE (PRACE) involved only one restriction enzyme, HaeIII, and a single electrophoretic separation less than 10 min. Full-range (10-200 bp) RFLP patterns of 12 less common Mycobacterium and 7 Nocardia spp. were investigated. A good agreement was observed between the sizes of restriction fragments resolved by CE and the real sizes deduced from sequence analysis. Including hsp65 gene patterns of 12 Mycobacterium spp. published earlier, differentiation was distinct among 24 Mycobacterium and 7 Nocardia spp. Some closely related species exhibiting similar biochemical characteristics could be well discriminated by an extra HaeIII digestion site. Thus, PRACE offers a nonprobe alternative for rapid identification of various cultured Mycobacterium and Nocardia to the species level.


Assuntos
Proteínas de Bactérias/genética , Chaperoninas/genética , Eletroforese Capilar/métodos , Mycobacterium/classificação , Nocardia/classificação , Polimorfismo de Fragmento de Restrição , Chaperonina 60 , DNA Bacteriano/genética , Desoxirribonucleases de Sítio Específico do Tipo II , Mycobacterium/genética , Nocardia/genética , Reação em Cadeia da Polimerase
13.
Am J Ophthalmol ; 143(1): 182-3, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17188068

RESUMO

PURPOSE: To describe a new technique, pyrosequencing, which allows for the rapid identification of Mycobacterium and Nocardia species. DESIGN: Interventional case report. METHODS: The medical records of a patient presenting with an infectious keratitis were reviewed. RESULTS: A case of Nocardia abscessus/arthrititis/asiatica keratitis was diagnosed in a young individual with the aid of pyrosequencing technology. Based on presumed antibiotic sensitivities, therapy with topical trimethoprim-sulfamethoxazole eyedrops was initiated, and the infection was cleared rapidly with minimal residual scarring. CONCLUSIONS: Pyrosequencing may be a useful tool in aiding the rapid diagnosis and treatment of ocular infections caused by slow-growing pathogens.


Assuntos
DNA Bacteriano/análise , Infecções Oculares Bacterianas/microbiologia , Ceratite/microbiologia , Nocardiose/microbiologia , Nocardia/genética , Análise de Sequência de DNA/métodos , Adulto , Anti-Infecciosos/uso terapêutico , Técnicas de Tipagem Bacteriana , Sequência de Bases , Infecções Oculares Bacterianas/diagnóstico , Infecções Oculares Bacterianas/tratamento farmacológico , Humanos , Ceratite/diagnóstico , Ceratite/tratamento farmacológico , Masculino , Dados de Sequência Molecular , Nocardia/isolamento & purificação , Nocardiose/diagnóstico , Nocardiose/tratamento farmacológico , Soluções Oftálmicas/uso terapêutico , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico
14.
Diagn Mol Pathol ; 15(2): 70-3, 2006 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-16778586

RESUMO

Progressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyoma virus. Electron microscopy and immunohistochemistry are the traditional methods of confirming the presence of the virus in brain biopsies from these patients. We studied the brain biopsies from 7 patients with PML and 6 patients without PML with chromogenic in situ hybridization (CISH) for the JC polyoma virus using a commercially available probe. The biopsies from the patients with the PML cases were proven to contain the JC polyoma virus by traditional and molecular methods. The CISH findings were compared with the known state of infection. All (7/7) of the biopsies from patients with PML were positive for the presence of polyoma virus by CISH, whereas the biopsies from patients without PML were uniformly negative. CISH seems to be a useful tool for the detection of the JC virus in brain biopsies from patients with PML, and is more accessible because a commercial probe is available.


Assuntos
Encéfalo/virologia , Vírus JC/genética , Vírus JC/isolamento & purificação , Leucoencefalopatia Multifocal Progressiva/virologia , Estudos de Casos e Controles , Compostos Cromogênicos , Humanos , Hibridização In Situ/métodos , Vírus JC/patogenicidade , Leucoencefalopatia Multifocal Progressiva/diagnóstico , Reação em Cadeia da Polimerase
15.
J Orthop Res ; 24(8): 1641-9, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16788984

RESUMO

We have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures. The DNA was extracted and a set of broad-range PCR primers that targeted a part of the 16S rDNA gene was used for pan-bacterial PCR. The amplicons were submitted for pyrosequencing and the resulting molecular Gram stain characteristics were recorded. Culture and direct Gram staining were performed using standard methods for all cases. Surgical specimens were reviewed histologically for all cases that had a discrepancy between culture and molecular results. There was an 86.7% (39/45) agreement between the traditional and molecular methods. In 12/14 (85.7%) culture-proven cases of bacterial infection, molecular Gram stain characteristics were in agreement with the culture results, while the conventional Gram stain result was in agreement only for five cases (35.7%). In the 31 culture negative cases, 27 cases were also PCR negative, whereas 4 were PCR positive. Three of these were characterized as gram negative and one as gram positive by this molecular method. Molecular determination of the Gram stain characteristics of bacteria that cause orthopedic infections may be achieved, in most instances, by this method. Further studies are necessary to understand the clinical importance of PCR-positive/culture-negative results.


Assuntos
Infecções por Bactérias Gram-Positivas/diagnóstico , Osteíte/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Infecções Estafilocócicas/diagnóstico , Staphylococcus/genética , Sequência de Bases , Candidíase/diagnóstico , Infecções por Corynebacterium/diagnóstico , DNA Bacteriano/análise , Violeta Genciana , Humanos , Técnicas Microbiológicas , Dados de Sequência Molecular , Osteíte/microbiologia , Fenazinas , Infecções por Proteus/diagnóstico , RNA Ribossômico 16S/genética , Análise de Sequência de DNA/métodos , Staphylococcus/isolamento & purificação
16.
Am J Trop Med Hyg ; 95(6): 1424-1427, 2016 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-27928089

RESUMO

A 58-year-old Korean-born woman with a history of seizures and psychiatric issues was found dead at home. Autopsy was notable for large, calcified nodules that had nearly replaced her right temporal lobe. Histologic examination revealed the presence of Paragonimus eggs. This case demonstrates a rare manifestation of an aberrantly migrated lung fluke that resulted in epilepsy and sudden death years after the initial infection.


Assuntos
Encefalopatias/parasitologia , Paragonimíase/patologia , Animais , Encéfalo/parasitologia , Encéfalo/patologia , Morte Súbita , Evolução Fatal , Feminino , Humanos , Pessoa de Meia-Idade , Paragonimíase/epidemiologia , Paragonimus/isolamento & purificação
17.
Am J Surg Pathol ; 40(8): 1070-4, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27158759

RESUMO

Cystoisospora belli, previously known as Isospora belli, is an obligate intracellular coccidian parasite that is most often associated with gastrointestinal disease in immunocompromised patients. In this study, we detail the clinicopathologic features of 18 cases of Cystoisospora infection affecting the gallbladder in immunocompetent individuals and compare them with a control group. Each case was reviewed for cholecystitis (none, acute, chronic), epithelial disarray, presence of intraepithelial lymphocytes (none, rare [≤5 per 20 epithelial cells], present [>5 per 20 epithelial cells]), architectural distortion, intramucosal eosinophilia, and mural thickening/serositis. The mean age of patients with Cystoisospora infection was 33 years and the male to female ratio 1:4.3. Cholecystectomy was performed for biliary dyskinesia (n=7), abdominal pain (n=7), suspected cholelithiasis (n=5), and cholecystitis (n=3). In 2 cases, Cystoisospora was found in donor gallbladders resected at the time of liver transplantation. Each case was characterized by eosinophilic, oval or banana-shaped intraepithelial parasites within perinuclear parasitophorous vacuoles. Most cases showed epithelial disarray and minimal intraepithelial lymphocytosis. Of the 11 cases with an average follow-up of 15 months, none had evidence of disease related to Cystoisospora infection within the biliary tract or elsewhere in the gastrointestinal tract. We present the largest series of gallbladder cystoisosporiasis in immunocompetent patients to date. Cystoisospora infection is underrecognized in the gallbladders of immunocompetent patients, in part due to the subtle findings in routine cholecystectomy specimens. On the basis of the clinical follow-up, gallbladder cystoisosporiasis in immunocompetent individuals appears to be a self-limited infection.


Assuntos
Doenças da Vesícula Biliar/patologia , Doenças da Vesícula Biliar/parasitologia , Isosporíase/patologia , Adolescente , Adulto , Feminino , Humanos , Isospora , Masculino , Pessoa de Meia-Idade , Adulto Jovem
18.
Diagn Microbiol Infect Dis ; 51(4): 245-50, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15808315

RESUMO

Pyrosequencing technology, sequencing by addition, was evaluated for categorization of mycobacterial isolates. One hundred and eighty-nine isolates, including 18 ATCC and Trudeau Mycobacterial Culture Collection (TMC) strains, were studied. There were 38 Mycobacterium tuberculosis complex, 27 M. kansasii, 27 MAI complex, 21 M. marinum, 14 M. gordonae, 20 M. chelonae-abscessus group, 10 M. fortuitum, 5 M. xenopi, 3 M. celatum, 2 M. terrae complex, 20 M. mucogenicum, and 2 M. scrofulaceum. Nucleic acid extracts were prepared from solid media or MGIT broth. Traditional PCR was performed with one of the primers biotinylated; the assay targeted a portion of the 16S rRNA gene that contains a hypervariable region, which has been previously shown to be useful for the identification of mycobacteria. The PSQ Sample Preparation Kit was used, and the biotinylated PCR product was processed to a single-stranded DNA template. The sequencing primer was hybridized to the DNA template in a PSQ96 plate. Incorporation of the complementary nucleotides resulted in light generation peaks, forming a pyrogram, which was evaluated by the instrument software. Thirty basepairs were used for isolate categorization. Manual interpretation of the sequences was performed if the quality of the 30-bp sequence was in doubt or if more than 4 bp homopolymers were recognized. Sequences with more than 5 bp of bad quality were deemed unacceptable. When blasted against GenBank, 179 of 189 sequences (94.7%) assigned isolates to the correct molecular genus or group. Ten M. gordonae isolates had more than 5 bp of bad quality sequence and were not accepted. Pyrosequencing of this hypervariable region afforded rapid and acceptable characterization of common, routinely isolated clinical Mycobacterium sp. Algorithms are recommended for further differentiation with an additional sequencing primer or additional biochemicals.


Assuntos
Técnicas de Tipagem Bacteriana , Difosfatos/metabolismo , Infecções por Mycobacterium/microbiologia , Mycobacterium/classificação , Análise de Sequência de DNA/métodos , Sequência de Bases , Humanos , Dados de Sequência Molecular , Mycobacterium/genética , Mycobacterium/isolamento & purificação , Mycobacterium tuberculosis/classificação , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/isolamento & purificação , Micobactérias não Tuberculosas/classificação , Micobactérias não Tuberculosas/genética , Reação em Cadeia da Polimerase , Análise de Sequência de DNA/instrumentação
19.
Diagn Mol Pathol ; 14(2): 83-9, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15905691

RESUMO

The bacteria associated with orthopaedic infections are usually common gram-positive and gram-negative bacteria. This fundamental grouping of bacteria is a necessary first step in the selection of appropriate antibiotics. Since polymerase chain reaction (PCR) is more rapid and may be more sensitive than culture, we developed a postamplification pyrosequencing method to subcategorize bacteria based on a few nucleotide polymorphisms in the 16S rRNA gene. We validated this method using well-characterized strains of bacteria and applied it to specimens from spinal surgery cases with suspected infections. Lysates of 114 bacteria including 75 species were created following standard cultivation to obtain DNA. The DNA was amplified by a broad-range real-time PCR. The amplicons were evaluated by pyrosequencing and were classified as gram-positive, gram-negative, or acid-fast bacilli based on the first three to five nucleotides sequenced. In addition, clinical cases of suspected infection were obtained from spinal surgery. The results of the "molecular Gram stain" were compared with the results of traditional Gram stain and culture. The lysates of 107 (93.9%) of the bacteria extracts tested were appropriately categorized as gram-positive and gram-negative or as acid-fast bacilli on the basis of this assay. The sensitivity and specificity of this assay were 100% and 97.4% for gram-positive and 88.3% and 100% for gram-negative isolates. All of the five clinical samples were appropriately categorized as containing gram-positive or gram-negative bacteria with this assay. This study demonstrates that high sensitivity and specificity of a molecular gram stain may be achieved using broad-range real-time PCR and pyrosequencing.


Assuntos
Infecções Bacterianas/diagnóstico , Doenças Ósseas Infecciosas/diagnóstico , Violeta Genciana , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Fenazinas , Complicações Pós-Operatórias , Análise de Sequência de DNA/métodos , Coluna Vertebral/cirurgia , DNA Bacteriano/análise , Feminino , Bactérias Gram-Negativas/genética , Bactérias Gram-Positivas/genética , Humanos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Infecções Relacionadas à Prótese/diagnóstico , RNA Ribossômico 16S/genética , Sensibilidade e Especificidade
20.
Clin Infect Dis ; 36(4): E58-60, 2003 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-12567321

RESUMO

We describe a patient with a urinary tract infection (UTI) caused by Pasteurella multocida. Pulsed-field gel electrophoresis revealed that the clinical isolate recovered from the patient was identical (100% band match) to P. multocida isolates recovered from the patient's cat, but the isolate differed from an isolate recovered from a visiting cat and from a laboratory control strain. The patient also had abnormal urologic anatomy secondary to surgery; this has also been associated with P. multocida UTI.


Assuntos
Gatos/microbiologia , Infecções por Pasteurella/transmissão , Pasteurella multocida/isolamento & purificação , Infecções Urinárias/transmissão , Animais , Portador Sadio , Transmissão de Doença Infecciosa , Feminino , Humanos , Pessoa de Meia-Idade , Infecções por Pasteurella/fisiopatologia , Infecções Urinárias/microbiologia , Infecções Urinárias/fisiopatologia
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