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1.
J Clin Microbiol ; 58(10)2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32817226

RESUMO

Mycoplasma pneumoniae is a major cause of community-acquired pneumonia. There are limited data in the United States on the molecular epidemiological characteristics of M. pneumoniae We collected 446 M. pneumoniae-positive specimens from 9 states between August 2012 and October 2018. Culture, antimicrobial susceptibility testing, P1 subtyping, and multilocus VNTR (variable-number tandem repeats) analysis (MLVA) were performed to characterize the isolates. Macrolide-resistant M. pneumoniae (MRMp) was detected in 37 (8.3%) specimens. P1 subtype 2 (P1-2) was the predominant P1 subtype (59.8%). P1 subtype distribution did not change significantly chronologically or geographically. The macrolide resistance rate in P1 subtype 1 (P1-1) samples was significantly higher than that in P1-2 (12.9% versus 5.5%). Six P1-2 variants were identified, including two novel types, and variant 2c was predominant (64.6%). P1-2 variants were distributed significantly differently among geographic regions. Classical P1-2 was more frequent in lower respiratory tract specimens and had longer p1 trinucleotide repeats. Classical P1-2 was most common in MRMp (35.7%), while variant 2c was most common in macrolide-susceptible M. pneumoniae (67.5%). Fifteen MLVA types were identified; 3-5-6-2 (41.7%), 4-5-7-2 (35.3%), and 3-6-6-2 (16.6%) were the major types, and four MLVA clusters were delineated. The distribution of MLVA types varied significantly over time and geographic location. The predominant MLVA type switched from 4-5-7-2 to 3-5-6-2 in 2015. MLVA type was associated with P1 subtypes and P1-2 variant types but not with macrolide resistance. To investigate the M. pneumoniae genotype shift and its impact on clinical presentations, additional surveillance programs targeting more diverse populations and prolonged sampling times are required.


Assuntos
Mycoplasma pneumoniae , Pneumonia por Mycoplasma , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana , Genótipo , Humanos , Macrolídeos/farmacologia , Mycoplasma pneumoniae/genética , Pneumonia por Mycoplasma/tratamento farmacológico , Pneumonia por Mycoplasma/epidemiologia , Estados Unidos/epidemiologia
2.
J Clin Microbiol ; 57(11)2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31484701

RESUMO

There are sparse data to indicate the extent that macrolide-resistant Mycoplasma pneumoniae (MRMp) occurs in the United States or its clinical significance. Between 2015 and 2018, hospitals in 8 states collected and stored respiratory specimens that tested positive for M. pneumoniae and sent them to the University of Alabama at Birmingham, where real-time PCR was performed for detection of 23S rRNA mutations known to confer macrolide resistance. MRMp was detected in 27 of 360 specimens (7.5%). MRMp prevalence was significantly higher in the South and East (18.3%) than in the West (2.1%). A2063G was the predominant 23S rRNA mutation detected. MICs for macrolide-susceptible M. pneumoniae (MSMp) were ≤0.008 µg/ml, whereas MICs for MRMp were 16 to 32 µg/ml. Patients with MRMp infection were more likely to have a history of immunodeficiency or malignancy. Otherwise, there were no other significant differences in the clinical features between patients infected with MRMp and those infected with MSMp, nor were there any differences in radiographic findings, hospitalization rates, viral coinfections, the mean duration of antimicrobial treatment, or clinical outcomes. There was no significant change in MRMp incidence over time or according to age, sex, race/ethnicity, or status as an inpatient or an outpatient. Patients with MRMp were more likely to have received a macrolide prior to presentation, and their treatment was more likely to have been changed to a fluoroquinolone after presentation. This is the first national surveillance program for M. pneumoniae in the United States. Additional surveillance is needed to assess the clinical significance of MRMp and to monitor changes in MRMp prevalence.


Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Macrolídeos/farmacologia , Mycoplasma pneumoniae/efeitos dos fármacos , Pneumonia por Mycoplasma/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Monitoramento Epidemiológico , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Mutação , Mycoplasma pneumoniae/genética , Pneumonia por Mycoplasma/microbiologia , Prevalência , RNA Ribossômico 23S/genética , Estados Unidos/epidemiologia , Adulto Jovem
3.
J Clin Microbiol ; 57(2)2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30463893

RESUMO

Group A Streptococcus (GAS) is one of the leading causes of bacterial pharyngitis. Early GAS diagnosis is critical for appropriate antibiotic administration that reduces the risk of GAS sequelae and limits spread of the infection. The Aries Group A Strep (GAS) assay (Luminex, Austin, TX) is a fully automated PCR assay for direct detection of GAS in throat swab specimens in less than 2 h with minimum hands-on time. This multicenter prospective study evaluated the clinical performance of the Aries GAS assay compared to that of Streptococcus pyogenes culture. Subjects with symptoms consistent with pharyngitis were enrolled across four sites in the United States, and a throat swab in liquid Amies medium was obtained. Aries and reference testing was performed within 72 and 48 h after sample collection, respectively. Of 623 throat swab specimens from patients with pharyngitis (93.6% <18 years old, 54.3% female), the reference method yielded valid results for 618 specimens. Reference and Aries assay testing showed GAS-positive results for 160 (25.9%) and 166 (26.9%) specimens, respectively. Compared to the reference method, Aries assay sensitivity was 97.5% (95% confidence interval [CI], 93.7% to 99.0%), specificity was 97.8% (95% CI, 96.0 to 98.8%), positive predictive value was 94.0% (95% CI, 89.3% to 96.7%), and negative predictive value was 99.1% (95% CI, 97.7% to 99.7%). There were 10 false-positive and four false-negative detections with the Aries assay. Discrepant analysis with bidirectional sequencing yielded concordant results with the Aries assay for nine of 14 discordant samples. The Aries assay had high sensitivity and specificity for qualitative detection of group A Streptococcus from patients with pharyngitis.


Assuntos
Automação Laboratorial/métodos , Técnicas de Diagnóstico Molecular/métodos , Reação em Cadeia da Polimerase/métodos , Infecções Estreptocócicas/diagnóstico , Streptococcus pyogenes/isolamento & purificação , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Faringe/microbiologia , Estudos Prospectivos , Sensibilidade e Especificidade , Infecções Estreptocócicas/microbiologia , Streptococcus pyogenes/classificação , Streptococcus pyogenes/genética , Fatores de Tempo , Estados Unidos , Adulto Jovem
4.
J Clin Microbiol ; 54(3): 535-42, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26607988

RESUMO

Staphylococcus pseudintermedius is a coagulase-positive species that colonizes the nares and anal mucosa of healthy dogs and cats. Human infections with S. pseudintermedius range in severity from bite wounds and rhinosinusitis to endocarditis; historically, these infections were thought to be uncommon, but new laboratory methods suggest that their true incidence is underreported. Oxacillin and cefoxitin disk and MIC tests were evaluated for the detection of mecA- or mecC-mediated methicillin resistance in 115 human and animal isolates of the Staphylococcus intermedius group (SIG), including 111 Staphylococcus pseudintermediusand 4 Staphylococcus delphini isolates, 37 of which were mecA positive. The disk and MIC breakpoints evaluated included the Clinical and Laboratory Standards Institute (CLSI) M100-S25 Staphylococcus aureus/Staphylococcus lugdunensis oxacillin MIC breakpoints and cefoxitin disk and MIC breakpoints, the CLSI M100-S25 coagulase-negative Staphylococcus (CoNS) oxacillin MIC breakpoint and cefoxitin disk breakpoint, the CLSI VET01-S2 S. pseudintermedius oxacillin MIC and disk breakpoints, and the European Committee on Antimicrobial Susceptibility Testing (EUCAST) S. pseudintermedius cefoxitin disk breakpoint. The oxacillin results interpreted by the VET01-S2 (disk and MIC) and M100-S25 CoNS (MIC) breakpoints agreed with the results of mecA/mecC PCR for all isolates, with the exception of one false-resistant result (1.3% of mecA/mecC PCR-negative isolates). In contrast, cefoxitin tests performed poorly, ranging from 3 to 89% false susceptibility (very major errors) and 0 to 48% false resistance (major errors). BD Phoenix, bioMérieux Vitek 2, and Beckman Coulter MicroScan commercial automated susceptibility test panel oxacillin MIC results were also evaluated and demonstrated >95% categorical agreement with mecA/mecC PCR results if interpreted by using the M100-S25 CoNS breakpoint. The Alere penicillin-binding protein 2a test accurately detected all mecA-positive isolates, although for four isolates, cefoxitin induction was required prior to testing. These data demonstrate that the cefoxitin surrogate test does not reliably detect the presence of mecA in S. pseudintermedius isolates and that laboratories should perform oxacillin disk or MIC tests of these isolates when they are encountered.


Assuntos
Cefoxitina/farmacologia , Resistência a Meticilina , Testes de Sensibilidade Microbiana/normas , Oxacilina/farmacologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus intermedius/efeitos dos fármacos , Animais , Humanos , Testes de Sensibilidade Microbiana/métodos
5.
Leukemia ; 23(10): 1836-46, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19494838

RESUMO

Interleukin-21 (IL-21) has been recently shown to modulate the growth of specific types of B-cell neoplasm. Here, we studied the biological effects of IL-21 in mantle cell lymphoma (MCL). All MCL cell lines and tumors examined expressed the IL-21 receptor. Addition of recombinant IL-21 (rIL-21) in vitro effectively induced STAT1 activation and apoptosis in MCL cells. As STAT1 is known to have tumor-suppressor functions, we hypothesized that STAT1 is important in mediating IL-21-induced apoptosis in MCL cells. In support of this hypothesis, inhibition of STAT1 expression using siRNA significantly decreased the apoptotic responses induced by IL-21. To further investigate the mechanism of IL-21-mediated apoptosis, we employed oligonucleotide arrays to evaluate changes in the expression of apoptosis-related genes induced by rIL-21; rIL-21 significantly upregulated three proapoptotic proteins (BIK, NIP3 and HARAKIRI) and downregulated two antiapoptotic proteins (BCL-2 and BCL-XL/S) as well as tumor necrosis factor-alpha. Using an ELISA-based assay, we demonstrated that rIL-21 significantly decreased the DNA binding of nuclear factor-kappaB, a transcriptional factor known to be a survival signal for MCL cells. To conclude, IL-21 can effectively induce apoptosis in MCL via a STAT1-dependent pathway. Further understanding of IL-21-mediated apoptosis in MCL may be useful in designing novel therapeutic approaches for this disease.


Assuntos
Apoptose/efeitos dos fármacos , Interleucinas/farmacologia , Linfoma de Célula do Manto/patologia , Fator de Transcrição STAT1/metabolismo , Western Blotting , Citometria de Fluxo , Imunofluorescência , Perfilação da Expressão Gênica , Humanos , Immunoblotting , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/metabolismo , Potencial da Membrana Mitocondrial , NF-kappa B/genética , NF-kappa B/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/farmacologia , Receptores de Interleucina-21/genética , Receptores de Interleucina-21/metabolismo , Proteínas Recombinantes/farmacologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Transcrição STAT1/antagonistas & inibidores , Fator de Transcrição STAT1/genética , Células Tumorais Cultivadas
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