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Updated: Aug 9, 2026
Cefoperazone-treated Mouse Model of Clinically-relevant Clostridium difficile Strain R20291
Published on: December 10, 2016
[Epidemiological study on cigar-shaped clostridia isolated in a local Japanese general hospital]
Yasushi Daimon1, Kaori Tanaka, Kunitomo Watanabe
1Clinical Laboratory, Kyoto Prefectural Yosanoumi Hospital.
Abstract:
Cigar-shaped clostridia such as Clostridium clostridioforme and Clostridium symbiosum have been found in serious infections such as bacteremia. In Japan, however, these strains are unrecognized as clinically significant because they are overlooked as unidentified gram-negative rods. We isolated 60 strains of cigar-shaped Clostridium spp. from 48 clinical specimens treated at our laboratory from November 2004 to September 2006. Of these, 19 (39.6%) were primary infections and 29 (60.4%) postsurgical. Primary infections included infected decubitus ulcer (7), peritonitis, intra abdominal abscess, sepsis (2 cases in each group), pyometra, Bartholin's gland abscess, and Fournier's gangrene (1 case in each group). Secondary infections included 28 cases of surgical site infection and 1 case of pyothorax. CRP in 30 cases (62.5%) exeeded 10 mg/dL. In 26 (54.2%), WBC exceeded 12,000/microL. The 60 isolated strains were as follows by 16S rRNA sequencing: Clostridium hathewayi (26.7%), C. clostridioforme (16.7%), Clostridium bolteae (18.3%), Clostridium citroniae (10%), Clostridium aldenense (8.3%), and Clostridium symbiosum (20%). In antimicrobial susceptibility, strains of C. hathe-wayi showed relatively higher MIC for cefotaxime (MIC50; 64 microg/mL, MIC90; 128 microg/mL). Three strains of C. bolteae were beta-lactamase-producing and their MICs for ampicillin exceeded 128 microg/mL.
Insights
Cigar-shaped Clostridium species, often misidentified, cause serious infections like bacteremia. This study identifies key species and their antimicrobial resistance, highlighting their clinical significance.
Area of Science:
- Medical Microbiology
- Infectious Diseases
- Clinical Bacteriology
Background:
- Cigar-shaped Clostridium species, including Clostridium clostridioforme and Clostridium symbiosum, are associated with severe infections.
- In Japan, these clinically significant bacteria are often overlooked and misidentified as Gram-negative rods.
Purpose of the Study:
- To identify cigar-shaped Clostridium species in clinical specimens.
- To determine the clinical significance and infection types associated with these isolates.
- To analyze antimicrobial susceptibility patterns of the identified Clostridium species.
Main Methods:
- Isolation and identification of 60 cigar-shaped Clostridium strains from 48 clinical specimens using 16S rRNA sequencing.
- Classification of infections as primary or postsurgical.
- Antimicrobial susceptibility testing, including Minimum Inhibitory Concentration (MIC) determination.
Main Results:
- Identified Clostridium hathewayi (26.7%), C. clostridioforme (16.7%), C. bolteae (18.3%), C. citroniae (10%), C. aldenense (8.3%), and C. symbiosum (20%).
- Infections included bacteremia, surgical site infections, and abscesses, with elevated C-reactive protein (CRP) and white blood cell (WBC) counts in many cases.
- C. hathewayi exhibited higher cefotaxime MICs, and some C. bolteae strains showed high ampicillin resistance due to beta-lactamase production.
Conclusions:
- Cigar-shaped Clostridium species are significant pathogens in various human infections.
- Accurate identification and antimicrobial susceptibility testing are crucial for effective treatment.
- Misidentification of these bacteria can lead to underestimation of their clinical importance.
