Bacterial aetiology and antimicrobial resistance of community-acquired pneumonia in the elderly and younger adults

Prevalence of gram negative bacteria causing community acquired pneumonia among adults in Mwanza City, Tanzania

BACKGROUND

Community acquired pneumonia (CAP) in adults is still a common and serious illness in the sub-Saharan Africa. Identification of the pathogens is crucial in the management of CAP. This study was done to determine the common bacterial pathogens, treatment outcomes and associated factors for microbiological confirmed CAP among adults attending the Bugando Medical Centre and Sekou Toure hospital in the city of Mwanza, Tanzania.

METHODS

This was a hospital based cross sectional study involving patients with community acquired pneumonia attending Bugando Medical Centre and Sekou Toure regional Hospital. Demographic and other data were collected using standardized data collection tool. Sputum culture was done followed by identification of the isolates and antibiotics susceptibility testing.

RESULTS

A total of 353 patients were enrolled in the study. Out of 353 sputum samples, 265(75%) were of good quality. Of 353 non-repetitive sputum cultures, 72/353 (20.4, 95% CI: 16.2-24.6) were positive for the bacterial pathogens with five patients having more than one pathogen. Good quality sputa had significantly higher yield of pathogenic bacteria than poor quality sputa (26.1% vs.3.4%, P = 0.001). The majority 64 (83.1%) of the isolates were gram negative bacteria. Common bacteria isolated were Klebsiella pneumoniae 23/77(29.9%), Streptococcus pyogenes 10/77 (13.0%), Pseudomonas aeruginosa 9/77 (11.7%) and Escherichia coli 7/77 (9.1%). Of 23 K. pneumoniae isolates, 20/23 (87.0%) were resistant to ceftriaxone. Resistance to ceftriaxone was found to be associated with prolongation of CAP symptoms (p = 0.009).

CONCLUSION

Gram negative bacteria resistant to ampicillin, amoxicillin/clavulanic acid and ceftriaxone were most frequently isolated bacteria among adults' patients with CAP attending BMC and Sekou Toure hospital. Routine sputum culture should be performed to guide appropriate treatment of CAP among adults in developing countries.

Bacteriology of community acquired pneumonia in adult patients at Felege Hiwot Referral Hospital, Northwest Ethiopia: a cross-sectional study

Background

Community acquired pneumonia (CAP) is reported as a common cause of lower respiratory tract infection worldwide. Bacterial pathogens and antimicrobial resistance (AMR) associated with this infection varied between geographical regions. Knowledge of the pathogens in a given area and their up-to-date AMR profile is essential for optimal management of patients. This study was aimed at assessing the type of bacterial isolates and their AMR among CAP adult patients at the Felege Hiwot Referral Hospital (FHRH), Northwest Ethiopia.

Methods

This cross-sectional study was conducted during 1 April to 30 July 2018. Demographic related data were collected from the study participants using a structured questionnaire. Sputum samples were collected and processed to identify pathogens using the conventional culture and biochemical tests as per the standard procedures. The Kirby Bauer disk diffusion method was implemented for the AMR testing. Descriptive and multivariable analysis was conducted using SPSS version 23.

Results

Among 414 presumptively diagnosed study participants for CAP, bacterial pathogens were identified from 167 (40.3%) participants. Among these, multidrug resistance (MDR) accounted for 127(76%) of the isolates. The predominant isolates were Streptococcus pneumoniae at 60(35.9%) and Klebsella pneumoniae at 30(18%). Overcrowded living conditions [AOR 1.579 (95%CI: 1.015–2.456)] and alcohol use [AOR 4.043 (95% CI, 2.537–6.443)] were found statistically associated with culture positive sputum.

Conclusions

The study showed high prevalence of mono- and multi-drug resistant isolates in the study area. Therefore, regular surveillance of the type of isolates and their AMR patterns should be considered. Interventions for reducing community acquired pneumonia should be integrated with lifestyle factors related to household and alcohol use.

Etiological Diagnosis of Community-Acquired Pneumonia in Adult Patients: A Prospective Hospital-Based Study in Mashhad, Iran

BACKGROUND

Pneumonia is the third most common cause of death in the world, and mortality is highest for patients who require hospitalization.

OBJECTIVES

This prospective observational study is an etiological survey of community-acquired pneumonia (CAP) over a 12-month period in the Iranian city of Mashhad. To our knowledge, this is one of the first prospective hospital-based studies to comprehensively evaluate the epidemiological, demographical, clinical, and prognostic factors of patients with CAP in Iran.

PATIENTS AND METHODS

We studied all adult patients (aged ≥ 16 years) with CAP admitted to Imam Reza Hospital, Mashhad, Iran, between February 2013 and January 2014. The etiological diagnosis of CAP was made through conventional culturing and staining of respiratory secretions (i.e. sputum and pleural fluid), standard BACTEC™ Plus Aerobic/F bottles for blood cultures, and the immunochromatographic assays BinaxNOW(®) Streptococcus pneumoniae antigen and BinaxNOW(®) Legionella pneumophila antigen for the detection of S. pneumoniae antigen and L. pneumophila serogroup 1 antigen, respectively.

RESULTS

Among 120 patients with CAP, the most common etiology was S. pneumoniae (24.4%), followed by Mycobacterium tuberculosis (17.5%), S. aureus (6.7%), polymicrobial agents including anaerobes (4.2%), complicated hydatid cyst (2.5%), Influenza A virus (4.2%; including 2 cases of mixed Influenza A-bacterial infection), and Klebsiella pneumoniae, Brucella melitensis, Mucor, and varicella, each in 0.8% of the patients. The diagnosis of pneumonia remained unknown in 49 (40%) patients.

CONCLUSIONS

Tuberculosis was an important cause of CAP in our region. Hence, it should be considered in all patients admitted with a CAP diagnosis.

New microbiota found in sputum from patients with community-acquired pneumonia

Community-acquired pneumonia (CAP) is a major concern in hospitals and the bacterial community of which has not been systemically discussed yet. Sputum from patients in the acute stages is a kind of accessible sample reflecting its features. In our study, we analyzed 45 sputum samples from 45 patients with CAP. Eighteen sputum samples from healthy people were chosen as the controls. Pyrosequencing of the 16s rDNA V3 hypervariable regions of all the bacteria contained in the sputum was used as a culture-independent method to disclose the community constitution. Also, our published data for hospital-acquired pneumonia (HAP) in sputum was used for comparison. By pyrosequencing, >90,000 DNA reads were detected. After being analyzed by tools in the Ribosomal Database Project, the reads were classified into five main phyla and >100 genera. At the phyla level, the reads' distribution of CAP is similar to that of healthy people and at genera level, the occurrence of each genus possesses their feature in three categories. Genera such as Streptococcus and Neisseria showed stability in their percentages, indicating that such genera are rarely affected by exogenous bacteria or antibiotics. The role of other genera such as Moraxella and Rothia in CAP should be emphasized. According to our analysis, the bacterial communities of CAP are with slight change when compared with those of healthy people, but have a large gap between HAP. Meanwhile, Rothia might be an important endogenous pneumonia-causing factor.