Alshahrani Mohammad Y, Alfaifi Mohammed, Ahmad Irfan, Alkhathami Ali Gaithan, Hakami Abdulrahim Refdan, Ahmad Hafiz, Alshehri Osama M, Dhakad Megh Singh
Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, King Khalid University, Abha, Saudi Arabia.
Department of Medical Microbiology and Immunology, RAK Medical & Health Sciences University, Ras Al Khaimah, United Arab Emirates.
Saudi J Biol Sci. 2020 Jun;27(6):1423-1427. doi: 10.1016/j.sjbs.2020.04.032. Epub 2020 Apr 23.
(PCP) remains a significant cause of mortality and morbidity in patients with respiratory infections. Accurate diagnosis of PCP is still a diagnostic challenge. Hence, the main objectives were to study the incidence of pneumonia infection among respiratory problems patients and to compare the real-time quantitative PCR technique with various diagnostic methodologies. Patients who have respiratory symptoms of PCP like breathlessness, cough, and fever were enrolled. Bronchoalveolar lavage (BAL) samples were collected and homogenized, and then smears were prepared for examination by Gomorimethanamine silver staining (GMSS), Immunofluorescent staining (IFAT), Toludine blue O (TBO), and Giemsa staining. Further, RT-PCR was also performed for the detection of PCP. The mean patients' age was 52 (SD ± 16) years. 41% were female, and 59% of the patients were male. Weight loss (80%), fever (92%), cough (100%), and dyspnea (76%) were the most common complaints. Twenty-eight patients have been diagnosed with pulmonary infiltrates using chest X-ray. Out of 100 patients, 35% were positive for PCP. The organism was detected using IFAT in all the 35 specimens, 15 of 35 (42.86%) by GMSS, 8 of 35 (17.6%) by Giemsa stain, and 1 of 35 (2.8%) was detected by TBO stains. RT-PCR showed that 39 patients was found to be positive for PCP. Thirty-five of these 39 patients had a positive IFAT (89.74%); the IFAT was negative or undefined in 4 samples. All 39 patients (100%) had signs and symptoms for PCP. Our results suggest that RT-PCR is still the most highly sensitive method for detection. In poor resource settings where RT-PCR and IFAT is not available, diagnosis of pneumonia remains a complicated issue. In settings where RT-PCR & IFAT are not available, GMSS staining may be the next best choice to detect PCP.
卡氏肺孢子虫肺炎（PCP）仍是呼吸道感染患者死亡和发病的重要原因。PCP的准确诊断仍然是一项诊断挑战。因此，主要目的是研究呼吸道疾病患者中肺炎感染的发生率，并将实时定量PCR技术与各种诊断方法进行比较。纳入有PCP呼吸道症状如呼吸困难、咳嗽和发热的患者。收集支气管肺泡灌洗（BAL）样本并匀浆，然后制备涂片，通过吉姆萨甲胺银染色（GMSS）、免疫荧光染色（IFAT）、甲苯胺蓝O（TBO）和吉姆萨染色进行检查。此外，还进行了逆转录聚合酶链反应（RT-PCR）以检测PCP。患者的平均年龄为52（标准差±16）岁。41%为女性，59%为男性。体重减轻（80%）、发热（92%）、咳嗽（100%）和呼吸困难（76%）是最常见的主诉。28例患者经胸部X线诊断为肺部浸润。在100例患者中，35%的PCP呈阳性。在所有35份标本中，通过IFAT检测到该病原体，GMSS检测出35份中的15份（42.86%），吉姆萨染色检测出35份中的8份（17.6%），TBO染色检测出35份中的1份（2.8%）。RT-PCR显示39例患者PCP呈阳性。这39例患者中有35例IFAT呈阳性（89.74%）；4份样本的IFAT为阴性或不确定。所有39例患者（100%）均有PCP的体征和症状。我们的结果表明，RT-PCR仍然是检测的最敏感方法。在资源匮乏且无法进行RT-PCR和IFAT的地区，肺炎的诊断仍然是一个复杂的问题。在无法进行RT-PCR和IFAT的地区，GMSS染色可能是检测PCP的次优选择。
