Distribution and in vitro drug susceptibility test of Nocardia in Xi'an

doi:10.3969/j.issn.1673-8640.2026.07.003

Abstract

Abstract:

Objective To understand the distribution of Nocardia in Xi'an and evaluate the differences between different in vitro drug susceptibility test methods，and to provide a reference for rational clinical drug use. Methods Totally，37 non-repetitive Nocardia isolates were collected from Xijing Hospital of Air Force Military Medical University from January 2015 to December 2023，and they were identified by mass spectrometry and confirmed by 16S rRNA gene sequencing. In vitro drug susceptibility test was performed by broth microdilution method and E test. Based on the results of broth microdilution method，the error rate of E test results was analyzed. Results The sequencing identification results of the 37 Nocardia isolates were as follows：10 isolates of Nocardia georgiana，5 isolates of Nocardia abscessus，4 isolates of Nocardia asteroides，Nocardia farcinica and Nocardia brasiliensis，3 isolates of Nocardia beijingensis，Nocardia caviae and Nocardia nova，and 1 isolate of Nocardia asiatica. No resistant isolates to linezolid and amikacin was found. The drug resistance rate to compound sulfamethoxazole was 2.70%，the drug resistance rates to imipenem，amoxicillin-clavulanic acid，ceftriaxone，tobramycin and minocycline were <22.00%，and the drug resistance rates to clarithromycin and ciprofloxacin were 51.35%-64.86%. Using broth microdilution method as reference method，the very major error（VME）rates of E test for minocycline，imipenem，tobramycin，doxycycline，amoxicillin-clavulanic acid，clarithromycin and moxifloxacin were 9.09%-100.00%. The major error（ME）rates for clarithromycin，amoxicillin-clavulanic acid and compound sulfamethoxazole were 25.00%，3.13% and 2.78%，respectively. Conclusions In Xi'an，Nocardia georgiana is the most common species isolated in clinical practice. Nocardia has a relatively high drug resistance rate to clarithromycin and ciprofloxacin，while linezolid，amikacin and compound sulfamethoxazole have good antibacterial activity against it. E test method has a higher VME and ME rates，and is not recommended for routine clinical use.

Key words: Nocardia, Mass spectrometry, Gene sequencing, Broth microdilution method, E test

CLC Number:

R379.1

YANG Peihong, ZHOU Shan, KANG Beipei, YANG Yuqi, LIU Hao, ZHOU Ke. Distribution and in vitro drug susceptibility test of Nocardia in Xi'an[J]. Laboratory Medicine, 2026, 41(7): 631-636.

Figures/Tables 4

References 22

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菌名	痰液/株	肺泡灌洗液/株	脓液/株	抽出物/株	分泌物/株	合计/[株（%）]
乔治教堂奴卡菌	8	1	0	1	0	10（27.03）
脓肿奴卡菌	0	3	1	0	1	5（13.51）
皮疽奴卡菌	1	2	1	0	0	4（10.81）
天美奴卡菌	2	2	0	0	0	4（10.81）
巴西奴卡菌	0	0	0	1	3	4（10.81）
北京奴卡菌	2	1	0	0	0	3（8.11）
豚鼠耳炎奴卡菌	3	0	0	0	0	3（8.11）
新奴卡菌	1	0	0	1	1	3（8.11）
亚洲奴卡菌	0	0	0	1	0	1（2.70）

菌名	痰液/株	肺泡灌洗液/株	脓液/株	抽出物/株	分泌物/株	合计/[株（%）]
乔治教堂奴卡菌	8	1	0	1	0	10（27.03）
脓肿奴卡菌	0	3	1	0	1	5（13.51）
皮疽奴卡菌	1	2	1	0	0	4（10.81）
天美奴卡菌	2	2	0	0	0	4（10.81）
巴西奴卡菌	0	0	0	1	3	4（10.81）
北京奴卡菌	2	1	0	0	0	3（8.11）
豚鼠耳炎奴卡菌	3	0	0	0	0	3（8.11）
新奴卡菌	1	0	0	1	1	3（8.11）
亚洲奴卡菌	0	0	0	1	0	1（2.70）

抗菌药物	微量肉汤稀释法/[株（%）]	E试验/[株（%）]
阿米卡星	0（0.00）	0（0.00）
利奈唑胺	0（0.00）	0（0.00）
复方磺胺甲噁唑	1（2.70）	0（0.00）
亚胺培南	8（21.62）	6（16.22）
阿莫西林-克拉维酸	5（13.51）	7（18.92）
头孢曲松	6（16.22）	7（18.92）
妥布霉素	7（18.92）	4（10.81）
米诺环素	4（10.81）	0（0.00）
多西环素	11（29.73）	0（0.00）
莫西沙星	12（32.43）	10（27.03）
克拉霉素	21（56.76）	19（51.35）
环丙沙星	24（64.86）	23（62.16）

抗菌药物	微量肉汤稀释法/[株（%）]	E试验/[株（%）]
阿米卡星	0（0.00）	0（0.00）
利奈唑胺	0（0.00）	0（0.00）
复方磺胺甲噁唑	1（2.70）	0（0.00）
亚胺培南	8（21.62）	6（16.22）
阿莫西林-克拉维酸	5（13.51）	7（18.92）
头孢曲松	6（16.22）	7（18.92）
妥布霉素	7（18.92）	4（10.81）
米诺环素	4（10.81）	0（0.00）
多西环素	11（29.73）	0（0.00）
莫西沙星	12（32.43）	10（27.03）
克拉霉素	21（56.76）	19（51.35）
环丙沙星	24（64.86）	23（62.16）

抗菌药物	EA	VME	ME	CA
阿米卡星	89.19	0.00	0.00	100.00
利奈唑胺	83.78	0.00	0.00	100.00
复方磺胺甲噁唑	86.49	0.00	2.78	97.30
亚胺培南	72.97	37.50	0.00	91.89
阿莫西林-克拉维酸	83.78	20.00	3.13	81.08
头孢曲松	70.27	0.00	0.00	75.68
妥布霉素	78.38	28.57	0.00	86.49
米诺环素	48.65	100.00	0.00	62.16
多西环素	54.05	27.27	0.00	56.76
莫西沙星	72.97	9.09	0.00	67.57
克拉霉素	70.27	9.52	25.00	78.38
环丙沙星	56.76	0.00	0.00	91.89