The impact of quantitative and semi-quantitative culture of respiratory tract secretions on clinical decisions in a patient with suspected pneumonia – case study
DOI:
https://doi.org/10.12775/JEHS.2023.45.01.005Keywords
Quantitative culture, Semi-quantitative culture, Endotracheal aspirate, Brochoalveolar lavage, Lower respiratory tract infections, PneumoniaAbstract
Pneumonia is one of the most common disease entities treated in the Intensive Care Unit. The standard diagnostic procedure for patients with suspected pneumonia is to evaluate the presence of symptoms of infection, physical examination, imaging, laboratory and microbiological tests, arterial blood gasometry and culture of respiratory tract secretions. In many Intensive Care Units, the preferred method of collecting material from the lower respiratory tract is an endotracheal aspirate. However, its semi-quantitative culture does not distinguish respiratory tract colonization from infection. Samples obtained by bronchoscopy are believed to be more representative of the presence of true pathogens in the lungs.
An 87-year-old patient with myasthenia gravis was admitted to the Intensive Care Unit for suspected pneumonia. Laboratory tests showed elevated inflammatory markers and a chest X-ray showed interstitial densities in the left lower lobe. The result of semi-quantitative culture of tracheal aspirate was heavy growth of Staphylococcus aureus and heavy growth of Pseudomonas aeruginosa. The result of the quantitative BAL culture was S.aureus MSSA 105 colony-forming unit (CFU) per ml, Pseudomonas aeruginosa 102 CFU/ml. To consider a microorganism responsible for infection, the number of bacteria cells must exceed a designated threshold. For BAL it is ≥104 CFU/ml, for TA it is ≥106 CFU/ml, for PSB it is ≥ 103/ml. In this case, the cutoff point for identifying the pathogen responsible for the infection was reached only by Staphylococcus aureus (105 CFU/ml), not by Pseudomonas aeruginosa (102 CFU/ml).
The final diagnosis was left-sided PN1 pneumonia of S.aureus etiology. A cloxacillin was used for the treatment. Clinical improvement was achieved.
The described case proves the advantage of quantitative culture over semi-quantitative culture of respiratory tract secretions. The advantage of bronchoalveolar lavage over tracheal aspirate is also noticeable.
References
Shokouhi S, Alavi Darazam I, Sadeghi M, Gachkar L, Dolatshahi S. Diagnostic Yield of a Direct Quantitative Smear of Lower Respiratory Tract Secretions in Patients with Suspected Pneumonia Compared to a Semi-quantitative Culture. Tanaffos. 2017;16(1):9–12. PMID: 28638419
European Center for Disease Prevention and Control. Surveillance of healthcare-associated infections and prevention indicators in European intensive care units. HAI-Net ICU protocol, version 2.2. Stockholm: ECDC; 2017. DOI: https://doi.org/10.2900/833186
Rattani S, Farooqi J, Jabeen G, Chandio S, Kash Q, Khan A, et al. Evaluation of semi-quantitative compared to quantitative cultures of tracheal aspirates for the yield of culturable respiratory pathogens – a cross-sectional study. BMC Pulm Med. 2020 Dec 29;20(1):284. DOI: https://doi.org/10.1186/s12890-020-01311-7
Tsukahara K, Johnson B, Klimowich K, Chiotos K, Jensen EA, Planet P, et al. Comparison of tracheal aspirate and bronchoalveolar lavage samples in the microbiological diagnosis of lower respiratory tract infection in pediatric patients. Pediatr Pulmonol. 2022 Oct 3;57(10):2405–10. DOI: https://doi.org/10.1002/ppul.26049
Anokar A, Jedge P, Shah J, Chougale S. The utility of a modified technique for lower respiratory tract sampling in COVID-19 ICU and review of diagnostic approaches in suspected ventilator associated pneumonia. Crit. Care Innov. 2021;4(3):1-14. DOI: https://doi.org/10.32114/CCI.2021.4.3.1.14
Scholte JBJ, van Dessel HA, Linssen CFM, Bergmans DCJJ, Savelkoul PHM, Roekaerts PMHJ, et al. Endotracheal Aspirate and Bronchoalveolar Lavage Fluid Analysis: Interchangeable Diagnostic Modalities in Suspected Ventilator-Associated Pneumonia? J Clin Microbiol. 2014 Oct;52(10):3597–604. DOI: https://doi.org/10.1128/JCM.01494-14
Patel PH, Antoine MH, Ullah S. Bronchoalveolar Lavage. 2022 Aug 28. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan. PMID: 28613513.
Hogea SP, Tudorache E, Pescaru C, Marc M, Oancea C. Bronchoalveolar lavage: role in the evaluation of pulmonary interstitial disease. Expert Rev Respir Med. 2020 Nov 1;14(11):1117–30. DOI: https://doi.org/10.1080/17476348.2020.1806063
Ramírez P, Valencia M, Torres A. Bronchoalveolar Lavage to Diagnose Respiratory Infections. Semin Respir Crit Care Med. 2007 Oct;28(5):525–33. DOI: https://doi.org/10.1055/s-2007-991524
Baselski V, Klutts JS, Baselski V, Klutts JS. Point-Counterpoint: Quantitative Cultures of Bronchoscopically Obtained Specimens Should Be Performed for Optimal Management of Ventilator-Associated Pneumonia. J Clin Microbiol. 2013 Mar;51(3):740–4. DOI: https://doi.org/10.1128/JCM.03383-12
Danin PE, Girou E, Legrand P, Louis B, Fodil R, Christov C, et al. Description and microbiology of endotracheal tube biofilm in mechanically ventilated subjects. Respir Care. 2015 Jan;60(1):21–9. DOI: https://doi.org/10.4187/respcare.02722
Ling L, Wong WT, Lipman J, Joynt GM. A Narrative Review on the Approach to Antimicrobial Use in Ventilated Patients with Multidrug Resistant Organisms in Respiratory Samples-To Treat or Not to Treat? That Is the Question. Antibiotics (Basel). 2022 Mar 27;11(4). DOI: https://doi.org/10.3390/antibiotics11040452.
Johanson WG, Dever LL. Nosocomial pneumonia. Intensive Care Med. 2003 Jan 4;29(1):23–9. DOI: https://doi.org/10.1007/s00134-002-1589-7
Eshwara VK, Mukhopadhyay C, Rello J. Community-acquired bacterial pneumonia in adults: An update. Indian J Med Res. 2020 Apr;151(4):287–302. DOI: https://doi.org/10.4103/ijmr.IJMR_1678_19
Yagmurdur H, Tezcan AH, Karakurt O, Leblebici F. The efficiency of routine endotracheal aspirate cultures compared to bronchoalveolar lavage cultures in ventilator-associated pneumonia diagnosis. Niger J Clin Pract. 2016;19(1):46–51. DOI: https://doi.org/10.4103/1119-3077.164327
Siegel SJ, Weiser JN. Mechanisms of Bacterial Colonization of the Respiratory Tract. Annu Rev Microbiol. 2015;69:425–44. DOI https://doi.org/10.1146/annurev-micro-091014-104209
Dani A. Colonization and infection. Cent European J Urol. 2014;67(1):86–7. DOI: https://doi.org/10.5173/ceju.2014.01.art19
Torres A, Lee N, Cilloniz C, Vila J, Van der Eerden M. Laboratory diagnosis of pneumonia in the molecular age. European Respiratory Journal. 2016 Dec;48(6):1764–78. DOI: https://doi.org/10.1183/13993003.01144-2016
Cilloniz C, Martin-Loeches I, Garcia-Vidal C, San Jose A, Torres A. Microbial Etiology of Pneumonia: Epidemiology, Diagnosis and Resistance Patterns. Int J Mol Sci. 2016 Dec 16;17(12). DOI: https://doi.org/10.3390/ijms17122120
Arulkumaran N, Routledge M, Schlebusch S, Lipman J, Conway Morris A. Antimicrobial-associated harm in critical care: a narrative review. Intensive Care Med. 2020 Feb;46(2):225–35. DOI: https://doi.org/10.1007/s00134-020-05929-3
de Souza Nunes LH, Bernardi Lora JF, Fanhani Cracco LA, da Costa Manuel JA, Westarb Cruz JA, Telles JP, et al. Pseudomonas aeruginosa in tracheal aspirate: Colonization, infection, and recurrence. Clin Respir J. 2023 May;17(5):439–46. DOI: https://doi.org/10.1111/crj.13612
Mielko KA, Jabłoński SJ, Milczewska J, Sands D, Łukaszewicz M, Młynarz P. Metabolomic studies of Pseudomonas aeruginosa. World J Microbiol Biotechnol. 2019 Nov 7;35(11):178. DOI: https://doi.org/10.1007/s11274-019-2739-1
Thi MTT, Wibowo D, Rehm BHA. Pseudomonas aeruginosa Biofilms. Int J Mol Sci. 2020 Nov 17;21(22). DOI: https://doi.org/10.3390/ijms21228671
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