Molecular detection of respiratory pathogens in community-acquired pneumonia involving adults

ABSTRACT In an in vitro pharmacodynamic model, a twice-daily cefdinir dosing regimen was more effective than a once-daily regimen against common bacterial respiratory pathogens in producing 3-log10killing and preventing the occurrence of regrowth at 24 h. Twice-daily administration is likely the more appropriate cefdinir dosing strategy for the treatment of community-acquired pneumonia.

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Tigecycline in the Treatment of Community-Acquired Pneumonia

Clinical Medicine Therapeutics ◽

10.4137/cmt.s2351 ◽

2009 ◽

Vol 1 ◽

pp. CMT.S2351

Author(s):

Daniel Curcio

Keyword(s):

Tetracycline Resistance ◽

Multidrug Resistant ◽

Community Acquired Pneumonia ◽

Phase Iii ◽

Resistant Bacteria ◽

Respiratory Pathogens ◽

Evaluable Population ◽

Intent To Treat ◽

Cure Rates

Tigecycline is a first-in-class glycylcycline, broad-spectrum, intravenous antibacterial developed to overcome the two major mechanisms of tetracycline resistance (ribosomal protection and efflux). The drug has been approved in US for community-acquired bacterial pneumonia in adults. In vitro, tigecycline had good activity against a range of Gram-positive, Gram-negative and atypical community-acquired respiratory tract pathogens implicated in community-acquired pneumonia (CAP), including community-acquired Staphylococcus aureus, penicillin-resistant Streptococus pneumoniae and multidrug-resistant Enterobacteriaceae. Nonetheless, tigecycline shows in vitro low activity against against P. aeruginosa. Tigecycline provides high intrapulmonary concentrations that exceed the MIC90 of most of these respiratory pathogens. The combined results of two well designed, phase III studies demonstrated that tigecycline 100 mg initially, followed by 50 mg every 12 hours for 7-14 days was not inferior to recommended dosages of levofloxacin in the treatment of hospitalized patients with CAP. Clinical cure rates were 89.7% versus 86.3% in the clinically evaluable population and 81.0% versus 79.7% in the clinical modified intent-to-treat population. Tigecycline represents an appropriate choice for empirical monotherapy in the treatment of CAP, mainly in patients with risk factors for infections due to resistant bacteria.

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Identification of P1 types and variants of Mycoplasma pneumoniae during an epidemic in Chile

Journal of Medical Microbiology ◽

10.1099/jmm.0.018333-0 ◽

2010 ◽

Vol 59 (8) ◽

pp. 925-929 ◽

Cited By ~ 17

Author(s):

María A. Martínez ◽

Mauricio Ruiz ◽

Enna Zunino ◽

Vivian Luchsinger ◽

Raúl Aguirre ◽

...

Keyword(s):

Variable Region ◽

Community Acquired Pneumonia ◽

Respiratory Pathogens ◽

Nucleotide Polymorphism ◽

Single Nucleotide ◽

Epidemic Period ◽

Transition Mutation ◽

Type Sequence

This study was conducted to determine the types of M. pneumoniae prevalent in adults presenting with community-acquired pneumonia during an epidemic period, and to scrutinize a variable region of the RepMP4 element for the detection of P1 variants. All 23 clinical specimens PCR-positive for M. pneumoniae obtained in two hospitals in Santiago, Chile, from 2005 to 2006 were typed by a multiplex PCR directly and then the RepMP4 fragment of 18 specimens was sequenced. A predominance of M. pneumoniae type 2 was found, 18 (78.3 %) specimens being grouped as type 2 and 5 (21.7 %) as type 1. Co-infection of M. pneumoniae with other respiratory pathogens was found in 10/23 (43.4 %) patients, but their frequency was not related to the M. pneumoniae type. Sequence analysis revealed a single nucleotide polymorphism, a transition mutation, in 50 % of amplicons belonging to type 1 and in 71.4 % of amplicons of type 2. The nucleotide changes were synonymous in each P1 variant. In conclusion, during the 2005–2006 epidemic in Santiago, both types of M. pneumoniae circulated. Although the analysed area in the RepMP4 was small, we detected the existence of P1 variants in the two types of this organism.

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2213. Etiology of Community-Acquired Pneumonia (CAP) in Hospitalized Native American Adults

Open Forum Infectious Diseases ◽

10.1093/ofid/ofz360.1891 ◽

2019 ◽

Vol 6 (Supplement_2) ◽

pp. S754-S755

Author(s):

Laura Hammitt ◽

Amanda Driscoll ◽

Robert Weatherholtz ◽

Raymond Reid ◽

Janene Colelay ◽

...

Keyword(s):

Native American ◽

Native Americans ◽

Blood Culture ◽

Influenza A ◽

Virus Detection ◽

Community Acquired Pneumonia ◽

Respiratory Pathogens ◽

Common Etiology ◽

Case Status ◽

Type 3

Abstract Background Native Americans experience a high burden of community-acquired pneumonia (CAP). Thirteen-valent pneumococcal conjugate vaccine (PCV13) was introduced for adults ≥65yrs in 2014. Data on CAP etiology can guide prevention and treatment. Methods We enrolled adults hospitalized with CAP and age-group-matched non-hospitalized controls on Navajo and White Mountain Apache tribal lands. Nasopharyngeal/oropharyngeal (NP/OP) swabs from cases and controls were tested by multiplex PCR for respiratory pathogens. Urine from cases and controls was tested for pneumococcus (Sp) by conventional (BinaxNOW) and serotype-specific urine antigen detection (UAD) for 24 serotypes (PCV13 types plus 2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20, 22F, 33F). Blood culture and chest radiographs (CXRs) were obtained from cases at the provider’s discretion. Radiographic pneumonia was determined by clinical interpretation of CXRs. Results From March 2016 to March 2018, we enrolled 580 CAP cases with CXR confirmation and 411 controls. Positive blood culture was identified in 42/483 (9%), of which 29 (69%) were Sp. Sp was detected in 164/572 (29%) cases (table). Of 125 cases with serotype information available, serotypes 3 (n = 35; 28%) 8 (n = 19; 15%) and 20 (n = 15; 12%) were the most common. Among 53 Sp cases aged ≥65 years, 26 (49%) were PCV13-type. Compared with blood culture, UAD was 100% sensitive and 100% concordant (n = 24). Viruses were detected by NP/OP PCR in 43% of CAP cases and 18% of controls. Influenza A, parainfluenza type 3, rhinovirus, and RSV were statistically significantly associated with case status. Among 263 cases in whom all diagnostic tests were collected, 63% had a pathogen detected: bacteria alone in 19%, viruses alone in 23%, and both bacterial and viral infection in 22%. Bacterial causes outnumbered viral causes when adjusting for virus detection in the control population. Conclusion Pneumococci were the most common etiology identified among Native American adults with CAP. UAD improved detection of pneumococcal CAP. Respiratory viruses also contributed substantially to CAP burden. Broader prevention strategies, including new vaccines, are required to prevent viral pneumonia and pneumococcal pneumonia caused by serotypes not contained in currently-available vaccines. Disclosures All authors: No reported disclosures.

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