Next Article in Journal
Combination Regimens with Colistin Sulfate versus Colistin Sulfate Monotherapy in the Treatment of Infections Caused by Carbapenem-Resistant Gram-Negative Bacilli
Next Article in Special Issue
Bacteriuria in Paediatric Oncology Patients: Clinical Features, Distribution and Antimicrobial Susceptibility of Bacterial Pathogens at University Hospital Centre Zagreb, Croatia over a 4-Year Period
Previous Article in Journal
Emergence of Cfr-Mediated Linezolid Resistance among Livestock-Associated Methicillin-Resistant Staphylococcus aureus (LA-MRSA) from Healthy Pigs in Portugal
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:

Epidemiology of Nocardia Species at a Tertiary Hospital in Southern Taiwan, 2012 to 2020: MLSA Phylogeny and Antimicrobial Susceptibility

Department of Laboratory Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 183301, Taiwan
Department of Laboratory Medicine, Chiayi Chang Gung Memorial Hospital, Chiayi 261363, Taiwan
Department of Medical Biotechnology and Laboratory Sciences, College of Medicine, Chang Gung University, Taoyuan 333302, Taiwan
Division of Infectious Diseases, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung 483301, Taiwan
Division of Infectious Diseases, Department of Internal Medicine, Chiayi Chang Gung Memorial Hospital, Chiayi 561363, Taiwan
School of Medicine, College of Medicine, Chang Gung University, Taoyuan 633302, Taiwan
Author to whom correspondence should be addressed.
Antibiotics 2022, 11(10), 1438;
Submission received: 20 September 2022 / Revised: 13 October 2022 / Accepted: 17 October 2022 / Published: 19 October 2022
(This article belongs to the Special Issue Epidemiology of Pathogens and Antimicrobial Resistance)


The identification and antimicrobial susceptibility of Nocardia spp. are essential for guiding antibiotic treatment. We investigated the species distribution and evaluated the antimicrobial susceptibility of Nocardia species collected in southern Taiwan from 2012 to 2020. A total of 77 Nocardia isolates were collected and identified to the species level using multi-locus sequence analysis (MLSA). The susceptibilities to 15 antibiotics for Nocardia isolates were determined by the broth microdilution method, and the MIC50 and MIC90 for each antibiotic against different species were analyzed. N. cyriacigeorgica was the leading isolate, accounting for 32.5% of all Nocardia isolates, and the prevalence of Nocardia isolates decreased in summer. All of the isolates were susceptible to trimethoprim/sulfamethoxazole, amikacin, and linezolid, whereas 90.9% were non-susceptible to cefepime and imipenem. The phylogenic tree by MLSA showed that the similarity between N. beijingensis and N. asiatica was as high as 99%, 73% between N. niigatensis and N. crassostreae, and 86% between N. cerradoensis and N. cyriacigeorgica. While trimethoprim/sulfamethoxazole, amikacin, and linezolid remained fully active against all of the Nocardia isolates tested, 90.9% of the isolates were non-susceptible to cefepime and imipenem.

1. Introduction

Nocardiosis is caused by several species of Nocardia, a ubiquitous bacterium in the environment that is transmitted by inhalation or direct cutaneous inoculation [1]. Nocardia species are aerobic, partially acid-fast, beaded, branched Gram-positive bacilli with colonies of filamentous, slow-growing, soil-borne bacteria [1,2]. Nocardia spp. is responsible for a variety of clinical infections, ranging from skin and soft tissue infections to respiratory and central nervous system infections [3]. Monitoring the epidemiological characteristics of nocardiosis including species distribution, clinical features, and antimicrobial susceptibility profiles is warranted to inform diagnostic and treatment decisions [4].
Different Nocardia species may have different geographic distributions, pathogenic characteristics, and antimicrobial susceptibility patterns [5]. Pulmonary nocardiosis usually leads to high mortality and morbidity if not diagnosed in time to initiate the appropriate antimicrobial treatment [6]. Therefore, the identification of Nocardia isolates at the species level and the determination of their antimicrobial susceptibility are critical for the delivery of appropriate patient care [7].
This study aimed to investigate the species distribution and evaluate the antimicrobial susceptibility patterns of individual Nocardia species isolated from patients seeking care at a referral hospital in southern Taiwan from 2012 to 2020. Speciation of Nocardia isolates was performed using multi-locus sequence analysis (MLSA).

2. Results

2.1. Patient Characteristics

During the 9-year study period, a total of 77 patients were diagnosed with nocardiosis, 63.6% of whom were male and had an age ranging from 31 to 97 years. The clinical characteristics of the 77 Nocardia isolates are shown in Table 1.

2.2. Distribution of Nocardia Species

Of the 77 Nocardia isolates, 12 type strains were identified under a phylogenetic tree constructed from the concatenated gyrB-16S rRNA-secA1-hsp65 sequences. N. cyriacigeorgica was the most common species (n = 25, 32.5%), followed by N. farcinica (n = 18, 23.4%), N. brasiliensis (n = 13, 16.9%), N. beijingensis (n = 9, 11.7%), N. asiatica (n = 3, 3.9%), N. asteroides and N. concava (n = 2, 2.6%), N. amikacinitolerans, N. cerradoensis, N. crassostreae, N. niigatensis, and N. otitidiscaviarum (n = 1, 1.3%).
The correlations between the drug susceptibility patterns and Nocardia species are shown in Table 2. The most common drug pattern was type V to type VIII (74.1%). In contrast to the drug pattern types described previously by McTaggart et al. [8], we found that both the N. farcinica and N. cyriacigeorgica strains were IPM-resistant and the N. cyriacigeorgica strains were also FEP-resistant.

2.3. Nocardia Species Profile by Analysis of Years and Months

In 2012, 2014, 2019, and 2020, the predominant species was N. cyriacigeorgica (Figure 1). In contrast, the predominant species identified in 2013, 2016, 2017, and 2018 was N. farcinica. N. brasiliensis was the predominant species in 2015. Figure 2 shows the monthly distribution of the Nocardia species, suggesting that the prevalence of Nocardia infections was lower in summer and higher in autumn.

2.4. Antibiotic Susceptibility Profiles

The MIC50 and MIC90 values (in µg/mL) and the MIC ranges and distributions for each Nocardia species are shown in Table 3. All Nocardia isolates in our study were susceptible to SXT, AN, and LZD. Of these isolates, 23.4% were non-susceptible to TOB. In contrast, 90.9% of Nocardia isolates were not susceptible to FEP and IPM, especially all isolates of N. cyriacigeorgica, N. farcinica, and N. brasiliensis. We also found that 83.1% of the isolated strains were non-susceptible to CLR, and 80.5% were non-susceptible to CIP. The susceptibility breakpoints for tigecycline and cefoxitin were not established.

2.5. PFGE for N. cyriacigeorgica

N. cyriacigeorgica was the most common species in this study. We randomly selected nine strains of N. cyriacigeorgica, which were isolated in 2019 and 2020 for PFGE analysis to determine the genetic relatedness among the strains. Figure 3 shows that all nine strains were isolated from different patients, and their parental similarities were less than 60%, indicating non-homologous strains.

2.6. Phylogenetic Tree by MLSA Scheme

In our study, there were 12 Nocardia spp. The differences in four-locus (gyrB-16S rRNA-secA1-hsp65) MLSA concatenated sequences among these 12 species and the evolutionary phylogenetic trees are shown in Figure 4. The similarity between N. beijingensis and N. asiatica was as high as 99%, and that between the two species and N. farcinica was 77%. N. beijingensis and N. asiatica belonged to the N. abscessus complex [7], and their nucleic acid similarity was up to 99%. N. niigatensis and N. crassostreae had a similarity of 73%. N. cerradoensis had an 86% similarity to N. cyriacigeorgica. Additionally, N. amikacinitolerans was independent and had greater differences than the other species.

3. Discussion

Recently, MALDI-TOF MS has been shown to provide an accurate identification of Nocardia species when an augmented Nocardia library is employed. However, while some species are easily identified (i.e., N. brasiliensis), for others, the identification has only been shown to extend to the complex level (N. abscessus complex, N. brevicatena-N. paucivorans complex, N. nova complex, and N. transvalensis complex). The identification of uncommon species remains a challenge [7,9]. Sequence analysis of the 16S rRNA gene is suggested as the “gold standard” for the identification of Nocardia isolates to the species level. However, when the identification to species level is based on the partial 5’ 16S rRNA sequencing, as in this case, a second genetic locus such as the secA1 gene for isolate identification is recommended because 16S rRNA sequence analysis alone provides insufficient species-level resolution for many Nocardia spp., whereas secA1 gene sequence analysis is more discriminatory and gives better resolution to the species level [10]. Both genes were included in the MLSA schema employed in this study for the species assignation to achieve higher accuracy and differentiation. Nevertheless, the identification of Nocardia isolates in some challenging species, species groups, or complexes is not possible with MLSA. In our study, there was a 99% similarity between N. beijingensis and N. asiatica in the MLSA analysis, and all of them belonged to the N. abscessus complex, which was difficult to distinguish.
Previous studies conducted before 2010 indicated that the most common Nocardia spp. in Taiwan was N. brasiliensis [11,12]. In contrast, N. farcinica was the most common isolated species in China from 2009 to 2021 [13]. N. nova complex organisms were the most common isolates in the United States before 2004 and Canada before 2008 [14,15], and N. cyriacigeorgica was the most common pathogen in Spain before 2008 [16]. N. cyriacigeorgica was the most common causative agent of pulmonary nocardiosis in southern Taiwan from 2004 to 2010 [17] and China from 2010 to 2020, where pulmonary nocardiosis (90.2%) was the most common clinical presentation of infection [18], which is consistent with our study predominated in lung infection (Table 1) conducted between 2012 and 2020. There are few recent epidemiological data on invasive nocardiosis in this region. Further studies are required to confirm whether N. cyriacigeorgica is an emerging pathogen in southern Taiwan.
The different species of Nocardia isolates exhibit diverse susceptibilities to antibiotics. Our study showed that all Nocardia spp. are susceptible to SXT, LZD, and AN. In contrast, the non-susceptibility rates of Nocardia spp. to DOX and MIN were 80.5% and 71.4%, respectively. Overall, SXT, LZD, and AN were the most active drugs for all Nocardia spp., which is consistent with the findings of other studies [8,10,19]. Our study showed that all Nocardia spp. were susceptible to TOB, except for N. farcinica. This suggests that TOB should be avoided in infections with N. farcinica in our region.
Although our study showed that most of the drug patterns were consistent with the drug pattern types suggested by McTaggart [8], different antibiograms were found in the current study. In agreement with the report of Tan et al. [10], high IPM resistance rates were observed in both N. farcinica and N. cyriacigeorgica, and high FEP resistance rates were observed in N. cyriacigeorgica in our study (Table 3). High IPM resistance in N. cyriacigeorgica was observed in Australia [20], but not in Spain [19] and Canada [8]. Another study of 151 Nocardia isolates conducted in four hospitals in Taiwan between 1998 and 2009 found that the three leading Nocardia spp. were N. brasiliensis, N. cyriacigeorgica, and N. farcinica. The susceptibility of N. brasiliensis, N. cyriacigeorgica, and N. farcinica to IPM was 47%, 100%, and 100%, respectively [11]. The higher rate of non-susceptibility of IPM observed in our study could either be a unique regional resistance profile of Nocardia spp. in southern Taiwan or selection pressure from the overuse of carbapenems [21,22]. This finding suggests that FEP and IPM should not be used empirically until the antimicrobial susceptibility results are available. Further epidemiological surveillance of the antimicrobial susceptibility profiles of Nocardia spp. is warranted to confirm our findings.
Nocardiosis occurs worldwide. Nocardia infections have increased in the past decades, likely due to improved detection and identification methods and the expanding immunocompromised population [3]. Although reports of community-acquired nocardiosis are common, few cases of nosocomial transmission of Nocardia species have been reported [23,24,25,26]. N. cyriacigeorgica has also been reported to cause outbreaks [27]. We performed a PFGE analysis for N. cyriacigeorgica, and the genetic relatedness of the strains from different patients were not homologous (Figure 3). Remarkably, no outbreaks occurred in this study. Our finding of a decrease in the prevalence of clinically isolated Nocardia spp. in summer from 2012 to 2020 is in contrast to the findings of an Australian environmental survey of Nocardia species isolated during a 1-year period from the foaming marine waters of the Sunshine Coast region [28], which suggests that hot weather is conducive to the growth of Nocardia. However, more studies of the prevalence of Nocardia species among clinical samples per month are needed to gain insights into the correlation of climate change and the distribution of Nocardia spp.
Our study had some limitations. First, the number of isolated Nocardia spp. in this study was still low, which may have prevented us from exactly determining the prevalence. Second, we did not investigate the molecular mechanisms of the antimicrobial resistance of the collected Nocardia strains to explain the regional differences in the antimicrobial susceptibility profiles.

4. Materials and Methods

4.1. Bacterial Isolates

Non-duplicated 77 isolates of Nocardia spp. collected from all patients who received a culture-confirmed diagnosis of nocardiosis at Kaohsiung Chang Gung Memorial Hospital (KCGMH) were included from 1 January 2012 to 31 December 2020. The KCGMH is a 2700-bed facility that serves as a primary care and tertiary referral center in southern Taiwan.

4.2. Housekeeping Gene Selection, DNA Extraction, PCR, and Sequencing

According to previous studies, four housekeeping genes (16S rRNA, secA1, gyrB, and hsp65) were selected [29,30]. DNA was extracted using a QIAGEN DNeasy Tissue Kit. The PCR products were referred to the Genome Sequencing Company for sequencing. The gene sequences were subsequently matched to those in the National Center for Biotechnology Information database (, accessed on 21 November 2021) to identify the Nocardia species [14,29]. The gene sequences were deposited in the GenBank database and their corresponding accession numbers are presented in Table S1.

4.3. Construction of Phylogenetic Tree

MLSA using concatenated sequences of gyrB-16S-secA1-hsp65 has previously been used to identify Nocardia species [29,30]. Primer sequences published by McTaggart et al. [31] are presented in Table S2. Phylogenetic trees were constructed using the neighbor-joining method (software: Molecular Evolutionary Genetics Analysis across Computing Platforms). Bootstrap values based on 1000 replications were listed as percentages at the branching points of the tree [32]. Phylogenetic trees were constructed using the neighbor-joining (NJ) genetic distance method [33] and performed using the ClustalW algorithm in the mega X software. The reliability of each tree topology was checked using 10,000 bootstrap replications [32,34].

4.4. Pulsed-Field Gel Electrophoresis (PFGE) Analysis

N. cyriacigeorgica was the most common species in this study, so we performed PFGE to clarify whether there was a possibility of nosocomial infection. The suspension (300 µL) and lysozyme (20 µL; 25 mg/mL) were added and incubated at 37 °C for 4 h after mixing. Total genomic DNA was prepared in agarose plugs and lysed in 5 mL of lysis buffer (25 mg lysozyme per mL and 20 µL proteinase K in TE buffer) for 4 h in a 56 °C water bath. The plugs were digested with XbaI. DNA fragments were separated on a 1% gel in a CHEF Mapper System (Bio-Rad, Mississauga, Ontario, Canada) with linear ramping pulse times of 1–30 s over 17.5, 6 V/cm at 14 °C. The Dice coefficients of the PFGE profiles were analyzed with an UPGMA dendrogram using GelCompar II version 6.6.11 (Applied Maths BVBA, Kortrijk, Belgium).

4.5. Antimicrobial Susceptibility Test

The susceptibility of the isolates to 15 commonly-used antibiotics was tested by the microbroth dilution method using Sensititre RAPMYCO TREK (Sensititre Susceptibility plates; TREK Diagnostic Systems Ltd. Cleveland, OH, USA) according to the manufacturer’s instructions. The strains recommended by the CLSI, S. aureus ATCC 29213 and E. coli ATCC 25922, were tested for quality control.
Antibiotics chosen for susceptibility testing in this study included amikacin (AN), amoxicillin/clavulanic acid (AMC), cefepime (FEP), cefoxitin (FOX), ceftriaxone (CRO), ciprofloxacin (CIP), clarithromycin (CLR), doxycycline (DOX), imipenem (IPM), linezolid (LZD), minocycline (MIN), moxifloxacin (MXF), tigecycline (TGC), tobramycin (TOB), and trimethoprim/sulfamethoxazole (SXT). The results were interpreted according to CLSI guideline M62 for aerobic actinomycetes [35].

4.6. Antimicrobial Susceptibility Patterns

According to Wallace et al. [36], six patterns of antibiotic susceptibility to Nocardia spp. have been proposed. These include N. abscessus complex (drug pattern I) and N. brevicatena/N. paucivorans (drug pattern II), Nocardia nova complex (drug pattern III), Nocardia transvalensis complex (drug pattern IV), N. farcinica (drug pattern V), and N. cyriacigeorgica (drug pattern VI) [36,37]. McTaggart et al. [8] suggested numerous rarely-occurring species using broth microdilution and divided them into four other drug patterns. We also characterized the antimicrobial resistance of several Nocardia isolates and profiled their antimicrobial susceptibility patterns.

5. Conclusions

N. cyriacigeorgica was the major Nocardia spp. identified in this study. SXT, LZD, and AN were the most active antimicrobial agents against all Nocardia strains identified. The distribution and antibiotic resistance characteristics of Nocardia species further our understanding of the diversity of circulating Nocardia species and inform the decision-making in the choice of empirical therapy.

Supplementary Materials

The following supporting information can be downloaded at:, Table S1: Accession number for four genes of these 12 type strains of Nocardia species as an indicator from GenBank, Table S2: Housekeeping genes primer.

Author Contributions

Conceptualization, C.-H.L. and S.-F.K.; Methodology, S.-F.K., F.-J.C., I.-C.L. and C.-C.C.; Writing-original draft preparation, S.-F.K.; Writing-review and editing, C.-H.L. All authors have read and agreed to the published version of the manuscript.


This work was supported by the Research Foundation of Kaohsiung Chang Gung Memorial Hospital (CMRPG8E1111 and CMRPG8K1581).

Institutional Review Board Statement

The study was conducted in accordance with the Declaration of Helsinki and approved by the Institutional Review Board of Chang Gung Medical Foundation (202001763B0C502, date of approval: 6 August 2020).

Informed Consent Statement

Patient consent was waived for this study because only anonymous data were retrospectively analyzed and published.

Data Availability Statement

The datasets generated and/or analyzed during the current study are available from the corresponding author upon reasonable request.


The authors would like to thank Chien-Ching Hung at the Department of Internal Medicine, National Taiwan University Hospital, Yunlin Branch, Yunlin, Taiwan for his critical review of this manuscript. We would also like to thank the Microbial and Virus Bank, Kaohsiung Chang Gung Memorial Hospital, for the microbiological collection work.

Conflicts of Interest

The authors declare no conflict of interest. The funders had no role in the study design; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results.


  1. Brown-Elliott, B.A.; Brown, J.M.; Conville, P.S.; Wallace, R.J., Jr. Clinical and laboratory features of the Nocardia spp. based on current molecular taxonomy. Clin. Microbiol. Rev. 2006, 19, 259–282. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  2. Duggal, S.D.; Chugh, T.D. Nocardiosis: A neglected disease. Med. Princ. Pract. 2020, 29, 514–523. [Google Scholar] [CrossRef] [PubMed]
  3. Williams, E.; Jenney, A.W.; Spelman, D.W. Nocardia bacteremia: A single-center retrospective review and a systematic review of the literature. Int. J. Infect. Dis. 2020, 92, 197–207. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  4. Huang, L.; Chen, X.; Xu, H.; Sun, L.; Li, C.; Guo, W.; Xiang, L.; Luo, G.; Cui, Y.; Lu, B. Clinical features, identification, antimicrobial resistance patterns of Nocardia species in China: 2009–2017. Diagn. Microbiol. Infect. Dis. 2019, 94, 165–172. [Google Scholar] [CrossRef]
  5. Lebeaux, D.; Bergeron, E.; Berthet, J.; Djadi-Prat, J.; Mouniée, D.; Boiron, P.; Lortholary, O.; Rodriguez-Nava, V. Antibiotic susceptibility testing and species identification of Nocardia isolates: A retrospective analysis of data from a French expert laboratory, 2010–2015. Clin. Microbiol. Infect. 2019, 25, 489–495. [Google Scholar] [CrossRef] [Green Version]
  6. Van den Bogaart, L.; Manuel, O. Antibiotic therapy for difficult-to-treat infections in lung transplant recipients: A practical approach. Antibiotics 2022, 11, 612. [Google Scholar] [CrossRef]
  7. Conville, P.S.; Brown-Elliott, B.A.; Smith, T.; Zelazny, A.M. The complexities of Nocardia taxonomy and identification. J. Clin. Microbiol. 2017, 56, e01419-17. [Google Scholar] [CrossRef] [Green Version]
  8. McTaggart, L.R.; Doucet, J.; Witkowska, M.; Richardson, S.E. Antimicrobial susceptibility among clinical Nocardia species identified by multilocus sequence analysis. Antimicrob. Agents Chemother. 2015, 59, 269–275. [Google Scholar] [CrossRef] [Green Version]
  9. Marín, M.; Ruiz, A.; Iglesias, C.; Quiroga, L.; Cercenado, E.; Martín-Rabadán, P.; Bouza, E.; Rodríguez-Sánchez, B. Identification of Nocardia species from clinical isolates using MALDI-TOF mass spectrometry. Clin. Microbiol. Infect. 2018, 24, 1342.e5–1342.e8. [Google Scholar] [CrossRef] [Green Version]
  10. Tan, Y.E.; Chen, S.C.; Halliday, C.L. Antimicrobial susceptibility profiles and species distribution of medically relevant Nocardia species: Results from a large tertiary laboratory in Australia. J. Glob. Antimicrob. Resist. 2020, 20, 110–117. [Google Scholar] [CrossRef]
  11. Lai, C.C.; Liu, W.L.; Ko, W.C.; Chen, Y.H.; Tan, H.R.; Huang, Y.T.; Hsueh, P.R. Multicenter study in Taiwan of the in vitro activities of nemonoxacin, tigecycline, doripenem, and other antimicrobial agents against clinical isolates of various Nocardia species. Antimicrob. Agents Chemother. 2011, 55, 2084–2091. [Google Scholar] [CrossRef] [Green Version]
  12. Liu, W.L.; Lai, C.C.; Ko, W.C.; Chen, Y.H.; Tang, H.J.; Huang, Y.L.; Huang, Y.T.; Hsueh, P.R. Clinical and microbiological characteristics of infections caused by various Nocardia species in Taiwan: A multicenter study from 1998 to 2010. Eur. J. Clin. Microbiol. Infect. Dis. 2011, 30, 1341–1347. [Google Scholar] [CrossRef]
  13. Wang, H.; Zhu, Y.; Cui, Q.; Wu, W.; Li, G.; Chen, D.; Xiang, L.; Qu, J.; Shi, D.; Lu, B. Epidemiology and Antimicrobial Resistance Profiles of the Nocardia Species in China, 2009 to 2021. Microbiol. Spectr. 2022, 10, e0156021. [Google Scholar] [CrossRef]
  14. Tremblay, J.; Thibert, L.; Alarie, I.; Valiquette, L.; Pépin, J. Nocardiosis in Quebec, Canada, 1988–2008. Clin. Microbiol. Infect. 2011, 17, 690–696. [Google Scholar] [CrossRef] [Green Version]
  15. Uhde, K.B.; Pathak, S.; McCullum, I.; Jannat-Khah, D.P., Jr.; Shadomy, S.V.; Dykewicz, C.A.; Clark, T.A.; Smith, T.L.; Brown, J.M. Antimicrobial-resistant Nocardia isolates, United States, 1995–2004. Clin. Infect. Dis. 2010, 51, 1445–1448. [Google Scholar] [CrossRef] [Green Version]
  16. Minero, M.V.; Marín, M.; Cercenado, E.; Rabadán, P.M.; Bouza, E.; Muñoz, P. Nocardiosis at the turn of the century. Medicine 2009, 88, 250–261. [Google Scholar] [CrossRef]
  17. Chen, Y.C.; Lee, C.H.; Chien, C.C.; Chao, T.L.; Lin, W.C.; Liu, J.W. Pulmonary nocardiosis in southern Taiwan. J. Microbiol. Immunol. Infect. 2013, 46, 441–447. [Google Scholar] [CrossRef]
  18. Wei, M.; Xu, X.; Yang, J.; Wang, P.; Liu, Y.; Wang, S.; Yang, C.; Gu, L. MLSA phylogeny and antimicrobial susceptibility of clinical Nocardia isolates: A multicenter retrospective study in China. BMC Microbiol. 2021, 21, 342. [Google Scholar] [CrossRef]
  19. Valdezate, S.; Garrido, N.; Carrasco, G.; Medina-Pascual, M.J.; Villalón, P.; Navarro, A.M.; Saéz-Nieto, J.A. Epidemiology and susceptibility to antimicrobial agents of the main Nocardia species in Spain. J. Antimicrob. Chemother. 2017, 72, 754–761. [Google Scholar]
  20. McGuinness, S.L.; Whiting, S.E.; Baird, R.; Currie, B.J.; Ralph, A.P.; Anstey, N.M.; Price, R.N.; Davis, J.S.; Tong, S.Y.C. Nocardiosis in the tropical northernterritory of Australia, 1997–2014. Open Forum Infect. Dis. 2016, 3, ofw208. [Google Scholar] [CrossRef] [Green Version]
  21. Grau, S.; Fondevilla, E.; Echeverría-Esnal, D.; Alcorta, A.; Limon, E.; Gudiol, F.; VINCat Program group. Widespread increase of empirical carbapenem use in acute care hospitals in Catalonia, Spain. Enferm. Infecc. Microbiol. Clin. 2019, 37, 36–40. [Google Scholar] [CrossRef]
  22. Rhodes, N.J.; Wagner, J.L.; Davis, S.L.; Bosso, J.A.; Goff, D.A.; Rybak, M.J.; Scheetz, M.H.; MAD-ID Research Network. Trends in and predictors of carbapenem consumption across north American hospitals: Results from a multicenter survey by the MAD-ID research network. Antimicrob. Agents Chemother. 2019, 63, e00327-19. [Google Scholar] [CrossRef] [Green Version]
  23. Yew, W.W.; Wong, P.C.; Kwan, S.Y.; Chan, C.Y.; Li, M.S. Two cases of Nocardia asteroides sternotomy infection treated with ofloxacin and a review of other active antimicrobial agents. J. Infect. 1991, 23, 297–302. [Google Scholar] [CrossRef]
  24. Exmelin, L.; Malbruny, B.; Vergnaud, M.; Prosvost, F.; Boiron, P.; Morel, C. Molecular study of nosocomial nocardiosis outbreak involving heart transplant recipients. J. Clin. Microbiol. 1996, 34, 1014–1016. [Google Scholar] [CrossRef] [Green Version]
  25. Blümel, J.; Blümel, E.; Yassin, A.F.; Schmidt-Rotte, H.; Schaal, K.P. Typing of Nocardia farcinica by pulsed-field gel electrophoresis reveals an endemic strain as source of hospital infections. J. Clin. Microbiol. 1998, 36, 118–122. [Google Scholar] [CrossRef] [Green Version]
  26. Wenger, P.N.; Brown, J.M.; McNeil, M.M.; Jarvis, W.R. Nocardia farcinica sternotomy site infections in patients following open heart surgery. J. Infect. Dis. 1998, 178, 1539–1543. [Google Scholar] [CrossRef] [Green Version]
  27. Apostolou, A.; Bolcen, S.J.; Dave, V.; Jani, N.; Lasker, B.A.; Tan, C.G.; Montana, B.; Brown, J.M.; Genese, C.A. Nocardia cyriacigeorgica infections attributable to unlicensed cosmetic procedures—An emerging public health problem? Clin. Infect. Dis. 2012, 55, 251–253. [Google Scholar] [CrossRef] [Green Version]
  28. Wright, L.; Katouli, M.; Kurtböke, D.İ. Isolation and characterization of Nocardiae associated with foaming coastal marine waters. Pathogens 2021, 10, 579. [Google Scholar] [CrossRef] [PubMed]
  29. Takeda, K.; Kang, Y.; Yazawa, K.; Gonoi, T.; Mikami, Y. Phylogenetic studies of Nocardia species based on gyrB gene analyses. J. Med. Microbiol. 2010, 59, 165–171. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  30. Kong, F.; Wang, H.; Zhang, E.; Sintchenko, V.; Xiao, M.; Sorrell, T.C.; Chen, X.; Chen, S.C. secA1 gene sequence polymorphisms for species identification of Nocardia species and recognition of intraspecies genetic diversity. J. Clin. Microbiol. 2010, 48, 3928–3934. [Google Scholar] [CrossRef] [PubMed] [Green Version]
  31. McTaggart, L.R.; Richardson, S.E.; Witkowska, M.; Zhang, S.X. Phylogeny and identification of Nocardia species on the basis of multilocus sequence analysis. J. Clin. Microbiol. 2010, 48, 4525–4533. [Google Scholar] [CrossRef]
  32. Kumar, S.; Stecher, G.; Li, M.; Knyaz, C.; Tamura, K. MEGA X: Molecular evolutionary genetics analysis across computing platforms. Mol. Biol. Evol. 2018, 35, 1547–1549. [Google Scholar] [CrossRef]
  33. Gascuel, O. BIONJ: An improved version of the NJ algorithm based on a simple model of sequence data. Mol. Biol. Evol. 1997, 14, 685–695. [Google Scholar] [CrossRef] [Green Version]
  34. Gnanam, H.; Rajapandian, S.; Gunasekaran, R.; Roshni Prithiviraj, S.; Ravindran, R.S.; Sen, S.; Prajna, L. Molecular identification of Nocardia species causing endophthalmitis using multilocus sequence analysis (MLSA): A 10-year perspective. J. Med. Microbiol. 2020, 9, 728–738. [Google Scholar] [CrossRef]
  35. Clinical and Laboratory Standards Institute. Performance Standards for Susceptibility Testing of Mycobacteria, Nocardia spp., and Other Aerobic Actinomycetes, 1st ed.; Approved standard M62; Clinical and Laboratory Standards Institute: Wayne, PA, USA, 2018. [Google Scholar]
  36. Wallace, R.J.; Steele, L.C., Jr.; Sumter, G.; Smith, J.M. Antimicrobial susceptibility patterns of Nocardia asteroides. Antimicrob. Agents Chemother. 1988, 32, 1776–1779. [Google Scholar] [CrossRef] [Green Version]
  37. Zhao, P.; Zhang, X.; Du, P.; Li, G.; Li, L.; Li, Z. Susceptibility profiles of Nocardia spp. to antimicrobial and antituberculotic agents detected by a microplate Alamar Blue assay. Sci. Rep. 2017, 7, 43660. [Google Scholar] [CrossRef]
Figure 1. Nocardia species distribution by year of isolation.
Figure 1. Nocardia species distribution by year of isolation.
Antibiotics 11 01438 g001
Figure 2. Nocardia species distribution by month of isolation.
Figure 2. Nocardia species distribution by month of isolation.
Antibiotics 11 01438 g002
Figure 3. Genetic relationships of N. cyriacigeorgica by PFGE analysis.
Figure 3. Genetic relationships of N. cyriacigeorgica by PFGE analysis.
Antibiotics 11 01438 g003
Figure 4. A phylogenetic neighbor-joining tree including these 12 types of strains as an indicator and the 77 clinical strains studied in the nine years based on the MLSA concatenated sequence.
Figure 4. A phylogenetic neighbor-joining tree including these 12 types of strains as an indicator and the 77 clinical strains studied in the nine years based on the MLSA concatenated sequence.
Antibiotics 11 01438 g004
Table 1. The clinical characteristics of the 77 included patients.
Table 1. The clinical characteristics of the 77 included patients.
Gender, n (%)
Male49 (63.6)
Age (years)
Median (range)76 (31–97)
Mean ± standard deviation70.4 ± 15.7
Specimen type, n (%)
Pus21 (27.3)
Sputum14 (18.2)
Wound11 (14.3)
Blood7 (9.1)
Abscess5 (6.5)
Bronchial washing7 (9.1)
Corneal ulcer4 (5.2)
Pleural effusion4 (5.2)
Synovial fluid2 (2.6)
Cerebrospinal fluid1 (1.3)
Bone tissue1 (1.3)
Site of involvement, n (%)
Lung35 (45.5)
Central nervous system9 (11.7)
Skin and soft tissue19 (24.7)
Bone and joint7 (9.1)
Blood stream7 (9.1)
Disseminated (including blood stream)18 (23.3)
Table 2. The antimicrobial susceptibility patterns of different Nocardia species.
Table 2. The antimicrobial susceptibility patterns of different Nocardia species.
Nocardia SpeciesNo. of IsolatesDrug Patterns TypesAntimicrobial Susceptibility Pattern
Non-Susceptible (%)Susceptible (%)
N. farcinica18VIPM (100)SXT (100)
FEP (100)LZD (100)
DOX (100)AN (100)
TOB (100)
CLR (100)
N. cyriacigeorgica25VICIP (100)SXT (100)
IPM (100)LZD (100)
MXF (100)AN (100)
FEP (100)TOB (100)
AMC (100)
CLR (92)
N. brasiliensis13VIIICIP (100)SXT (100)
IPM (100)LZD (100)
FEP (100)AN (100)
CRO (92)TOB (100)
DOX (100)
CLR (92)
N. otitidiscaviarium1VIICIP (100)SXT (100)
IPM (100)LZD (100)
FEP (100)AN (100)
AMC (100)TOB (100)
CRO (100)
CLR (100)
Abbreviations: AN, amikacin; AMC, amoxicillin/clavulanic acid 2:1 ratio; CIP, ciprofloxacin; CLR, clarithromycin; CRO, ceftriaxone; DOX, doxycycline; FEP, cefepime; IPM, imipenem; LZD, linezolid; MIN, minocycline; MXF, moxifloxacin; SXT, trimethoprim/sulfamethoxazole; TOB, tobramycin.
Table 3. The antimicrobial susceptibility test results.
Table 3. The antimicrobial susceptibility test results.
Antimicrobial AgentSpecies (No. of Strains Tested)
N. cyriacigeorgica (25)N. brasiliensis (13)N. farcinica (18)N. niigatensis
N. asteroides (2)N. beijingensis (9)N. otitidiscaviarum (1)N. crassostreae (1)N. concava (2)N. cerradoensis (1)N. asiatica (3)N. amikacinitolerans (1)
Sulfamethoxazole (SXT)
Resistant [n (%)]000000000000
Intermediate [n (%)]000000000000
Susceptible [n (%)]25 (100)13 (100)18 (100)1 (100)2 (100)9 (100)1 (100)1 (100)2 (100)1 (100)3 (100)1 (100)
MIC50 [µg/mL]0.25/4.750.5/9.51/19 0.25/4.75 0.25/4.75
MIC90 [µg/mL]0.5/9.50.5/9.52/38 1/19 0.25/4.75
Linezolid (LZD)
Resistant [n (%)]000000000000
Intermediate [n (%)]000000000000
Susceptible [n (%)]25 (100)13 (100)18 (100)1 (100)2 (100)9 (100)1 (100)1 (100)2 (100)1 (100)3 (100)1 (100)
MIC50 [µg/mL]222 1 1
MIC90 [µg/mL]244 2 1
Ciprofloxacin (CIP)
Resistant [n (%)]25 (100)13 (100)4 (22.2)02 (100)5 (55.6)1 (100)1 (100)1 (50)03 (100)1 (100)
Intermediate [n (%)]003 (16.7)1 (100)01 (11.1)001 (50)000
Susceptible [n (%)]0011 (61.1)003 (33.3)0001 (100)00
MIC50 [µg/mL]>4>41 4 >4
MIC90 [µg/mL]>4>4>4 >4 >4
Imipenem (IPM)
Resistant [n (%)]21 (84.0)10 (76.9)14 (77.8)1 (100)05 (55.5)1 (100)1 (100)2 (100)001 (100)
Intermediate [n (%)]4 (16.0)3 (23.1)4 (22.2)02 (100)1 (11.2)000000
Susceptible [n (%)]000003 (33.3)0001 (100)3 (100)0
MIC50 [µg/mL]163216 16 2
MIC90 [µg/mL]16>6432 64 4
Moxifloxacin (MXF)
Resistant [n (%)]24 (96.0)04 (22.2)01 (50)2 (22.3)000001 (100)
Intermediate [n (%)]1 (4.0)11 (84.6)001 (50)3 (33.3)1 (100)001 (100)00
Susceptible [n (%)]02 (15.4)14 (77.8)1 (100)04 (44.4)01 (100)2 (100)03 (100)0
MIC50 [µg/mL]420.25 2 8
MIC90 [µg/mL]824 >8 >8
Cefepime (FEP)
Resistant [n (%)]16 (64.0)12 (92.3)16 (88.8)1 (100)2 (100)4 (44.4)1 (100)1 (100)2 (100)001 (100)
Intermediate [n (%)]9 (36.0)1 (7.8)2 (11.2)002 (22.3)000000
Susceptible [n (%)]000003 (33.3)0001 (100)3 (100)0
MIC50 [µg/mL]32>32>32 16 8
MIC90 [µg/mL]>32>32>32 32 8
Cefoxitin (FOX)
MIC range64–12816–12864–128>12816–648–32>128>128>128644–16>64
Amoxicillin/clavulanic acid 2:1 ratio (AMC)
Resistant [n (%)]23 (92.0)1 (7.7)3 (16.7)1 (100)2 (100)4 (44.5)1 (100)1 (100)2 (100)03 (100)0
Intermediate [n (%)]2 (8.0)2 (15.4)12 (66.6)000000000
Susceptible [n (%)]010 (76.9)3 (16.7)005 (55.5)0001 (100)01 (100)
MIC50 [µg/mL]32/168/416/8 8/4 >64/32
MIC90 [µg/mL]64/3216/832/16 >64/32 >64/32
Amikacin (AN)
Resistant [n (%)]000000000000
Intermediate [n (%)]000000000000
Susceptible [n (%)]25 (100)13 (100)18 (100)1 (100)2 (100)9 (100)1 (100)1 (100)2 (100)1 (100)3 (100)1 (100)
MIC50 [µg/mL]111 1 1
MIC90 [µg/mL]111 1 1
Ceftriaxone (CRO)
Resistant [n (%)]2 (8.0)10 (76.9)15 (83.3)1 (100)01 (11.1)1 (100)1 (100)2 (100)001 (100)
Intermediate [n (%)]8 (32.0)2 (15.4)1 (5.6)003 (33.3)000000
Susceptible [n (%)]15 (60.0)1 (7.7)2 (11.1)02 (100)5 (55.6)0001 (100)3 (100)0
MIC50 [µg/mL]8>64>64 4 4
MIC90 [µg/mL]32>64>64 32 4
Doxycycline (DOX)
Resistant [n (%)]01 (7.7)1 (5.6)1 (100)00002 (100)000
Intermediate [n (%)]17 (68.0)12 (92.3)17 (94.4)02 (100)6 (66.7)1 (100)1 (100)01 (100)00
Susceptible [n (%)]8 (32.0)00003 (33.3)00003 (100)1 (100)
MIC50 [µg/mL]244 2 0.12
MIC90 [µg/mL]444 4 0.12
Minocycline (MIN)
Resistant [n (%)]000000002 (100)000
Intermediate [n (%)]17 (68.0)11 (84.6)17 (94.4)1 (100)2 (100)3 (33.3)1 (100)1 (100)0000
Susceptible [n (%)]8 (32.0)2 (15.4)1 (5.6)006 (66.7)0001 (100)3 (100)1 (100)
MIC50 [µg/mL]244 1 1
MIC90 [µg/mL]444 2 1
Tigecycline (TGC)
MIC range0.25–20.25–0.50.5–410.5–10.12–0.5122 (100)0.120.252
Tobramycin (TOB)
Resistant [n (%)]0016 (88.9)000000000
Intermediate [n (%)]002 (11.1)000000000
Susceptible [n (%)]25 (100)13 (100)01 (100)2 (100)9 (100)1 (100)1 (100)2 (100)1 (100)3 (100)1 (100)
MIC50 [µg/mL]1116 1 1
MIC90 [µg/mL]11>16 1 1
Clarithromycin (CLR)
Resistant [n (%)]22 (88.0)9 (69.2)18 (100)1 (100)2 (100)2 (22.2)1 (100)1 (100)001 (33.3)1 (100)
Intermediate [n (%)]1 (4.0)3 (23.0)0002 (22.2)000000
Susceptible [n (%)]2 (8.0)1 (7.8)0005 (55.6)002 (100)1 (100)2 (66.7)0
MIC50 [µg/mL]>168>16 1 1
MIC90 [µg/mL]>16>16>16 16 16
A comparison of the activities of different antibiotics against N. cyriacigeorgica and N. farcinica revealed that the MIC90 values of MXF and AMC against N. cyriacigeorgica were higher than those against N. farcinica. In contrast, the MIC90 values of SXT, LZD, IPM, CRO, and TGC against N. cyriacigeorgica were lower than those against N. farcinica (Table 3).
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Share and Cite

MDPI and ACS Style

Kuo, S.-F.; Chen, F.-J.; Lan, I.-C.; Chien, C.-C.; Lee, C.-H. Epidemiology of Nocardia Species at a Tertiary Hospital in Southern Taiwan, 2012 to 2020: MLSA Phylogeny and Antimicrobial Susceptibility. Antibiotics 2022, 11, 1438.

AMA Style

Kuo S-F, Chen F-J, Lan I-C, Chien C-C, Lee C-H. Epidemiology of Nocardia Species at a Tertiary Hospital in Southern Taiwan, 2012 to 2020: MLSA Phylogeny and Antimicrobial Susceptibility. Antibiotics. 2022; 11(10):1438.

Chicago/Turabian Style

Kuo, Shu-Fang, Fang-Ju Chen, I-Chia Lan, Chun-Chih Chien, and Chen-Hsiang Lee. 2022. "Epidemiology of Nocardia Species at a Tertiary Hospital in Southern Taiwan, 2012 to 2020: MLSA Phylogeny and Antimicrobial Susceptibility" Antibiotics 11, no. 10: 1438.

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop