You are currently viewing a new version of our website. To view the old version click .
MDPIMDPI
Search all articles
Microorganisms
Download PDF
  • Review
  • Open Access

24 May 2025

The Emergence of Bacteroides pyogenes as a Human Pathogen of Animal Origin: A Narrative Review

,
,
,
,
,
and
Clinical Microbiology and Virology Unit, “A. Manzoni” Hospital, 23900 Lecco, Italy
*
Author to whom correspondence should be addressed.
†
These authors contributed equally to this work.
Microorganisms2025, 13(6), 1200;https://doi.org/10.3390/microorganisms13061200
This article belongs to the Section Medical Microbiology
Version Notes
Order Reprints

Abstract

Bacteroides pyogenes is a Gram-negative obligate anaerobe rod. It is naturally found in the oral microbiome of cats and dogs, which represents a primary source of disease for humans. The present review provides an update on the role of B. pyogenes as a pathogen responsible for infections in humans. Indeed, an increasing number of B. pyogenes infections have been reported in recent years, including skin and soft tissue infections as well as severe diseases like osteomyelitis, Lemierre’s syndrome, and bloodstream infection. Pre-analytical and analytical phases are crucial to guarantee the isolation of anaerobic bacteria, including B. pyogenes. Moreover, the introduction of MALDI-TOF mass spectrometry and 16S rRNA sequencing in clinical microbiology laboratories may be partially responsible for the increasing number of reports of B. pyogenes infections. However, the mechanisms underlying the pathogenicity of B. pyogenes remain poorly understood and require further investigations. Indeed, despite common antimicrobial susceptibilities, infections frequently persist and require multiple courses of antibiotics. In addition, based on literature data, this review indicates that treatment of skin and soft tissue infections often necessitates surgical procedures and hospitalization.

1. Introduction

The genus Bacteroides belongs to the Bacteroidaceae family, the order Bacteroidales, the class Bacteroidia, and the phyla Bacteroidota (1 of 41 bacterial phyla), and includes at least fifty species [1]. Bacteria belonging to the genus Bacteroides are obligately anaerobic Gram-negative, non-spore-forming, non-motile rods. These bacteria have a critical role as commensal organisms in the human gut but are also involved in human disease, having a potential pathogenic role outside the gut [2]. Among anaerobes, Bacteroides are the most frequently isolated in clinical specimens [3]. In particular, Bacteroides fragilis was the first member of the genus recognized in 1898 as a human pathogen [4] and, to date, is still considered the most virulent [3]. Bacteroides thetaiotaomicron, Bacteroides uniformis, and Bacteroides vulgatus are considered other clinically relevant species.
Advances in microbiological diagnostic techniques, including the increasing use of Matrix-Assisted Laser Desorption Ionization–time-of-flight Mass Spectrometry (MALDI-TOF MS), and the use of 16S rRNA sequencing have allowed the increasing isolation of “new” or previously rarely described organisms, including Bacteroides pyogenes.
B. pyogenes (py.o’ge.nes. Gr. n. pyum pus; Gr. v. gennaio produce; M.L. adj. pyogenes pus-producing) was first described with Bacteroides suis from the abscesses and feces of pigs by Benno et al. in 1983 [5] and then isolated from uteri of dairy cows with metritis and from horses’ wounds [6,7,8]. In 1997, Forsblom and colleagues reported the presence of B. pyogenes and Bacteroides tectum as major components of the anaerobic, Gram-negative, saccharolytic microflora of dogs and their possible role in the development of periodontal disease [9].
Sakamoto et al. studied the B. pyogenes genome, concluding that B. suis and B. tectus are heterotypic synonyms of B. pyogenes, showing 100% similarity for the hsp60 and 16S rRNA genes [10]. Four years later, analysis by whole-genome sequencing of these three strains revealed the diversification of B. pyogenes strains isolated from different animals [11]. Sakamoto et al. concluded that further genome analysis will improve our understanding of this species [11]. B. pyogenes is included in the Bacteroides fragilis group [12].
B. pyogenes is usually considered an uncommon but significant human pathogen. However, an increasing number of reports are currently describing its isolation in human clinical specimens, particularly in those collected from wounds [3,13]. Indeed, B. pyogenes is a component of the oral microbiota of animals, like dogs and cats [9,14], and can be transmitted to humans through animal bites. The high numbers of domestic dogs and cats in the European Union in 2023, estimated at over 65 million and 75 million, respectively [15,16], highlights the possible growing impact of B. pyogenes in the development of human infections.

2. Materials and Methods

2.1. Search Strategy and Inclusion and Exclusion Criteria

This narrative review aims to summarize all the data on B. pyogenes infections in humans published in the literature. Information regarding patients’ demographics, clinical characteristics, site of infection, clinical presentation, and treatment provided were described. There was a particular focus on data regarding microbiological characteristics and methodologies used for identification and antimicrobial susceptibility testing (AST). By using the PubMed/Medline database, searches for relevant articles were performed with the following item: “(Bacteroides pyogenes)”. Studies providing original data, such as case reports and letters to the editor providing information on B. pyogenes infections in humans and published up to 31 January 2025 were included in the review. Studies regarding infections and/or colonization in animals were excluded from the analysis. The references of included articles were also examined to identify any studies potentially missed in the initial search.

2.2. Data Extraction

After the initial screening, the following data were extracted from each included study: publication year, age and gender of patients, type of infection, contact with animals, treatment (antibiotic therapy and/or surgical procedure), underlying disease, and hospitalization. Other relevant microbiological data were collected: type of sample, method of identification, antimicrobial susceptibility testing profile and co-isolated bacteria.

3. Results

3.1. Literature Search

The search strategy yielded 42 references; 36 articles were excluded based on exclusion criteria as previously described. Overall, 16 studies were included and analyzed: 9 case reports, 5 letters to the editor and 2 articles, describing a total of 39 cases of infection.

3.2. Epidemiology of B. pyogenes Infections

B. pyogenes is an obligate anaerobe commensal from the oral cavity of cats and dogs. B. pyogenes infections have been described in the United States [17,18] and different countries from Europe [3,13,19,20,21,22], Asia [23,24,25,26,27,28], and Oceania [29,30].
Table 1 reports clinical features of B. pyogenes infections described in the literature. Skin and soft tissue infections, mainly associated with animal bites, are the most frequent human infections caused by this microorganism [3,13,17,19,22,23,24,26,29]. B. pyogenes can also be responsible for severe diseases, such as bloodstream infections [13,22,23,27], bone infections including osteomyelitis [3,19,20], joint prosthesis infections [21], and intra-abdominal infections [3,25,27]. A case of Lemierre’s syndrome [18], one multiple lung abscess [30], and one urinary tract infection [3] were also described (Table 1 and Table 2). Notably, in some cases, a single patient can develop an infection from B. pyogenes in different anatomical sites, as reported by Park and colleagues, who described the presence of B. pyogenes in blood and material from a liver abscess [27], or by Chen and colleagues, who identified B. pyogenes in blood and purulent exudate from a head injury [23].
Table 1. Clinical features of Bacteroides pyogenes infections reported in the literature, including age, gender, type of infection, contact with animals, and treatment.
Table 2. Summary of Bacteroides pyogenes infections reported in the literature.
The medical history of patients is not always complete and often underlying pathologies are not reported. However, in some cases, underlying diseases were described, with the most frequently reported being diabetes and history of oncology (Table 2 and Supplementary Table S1).
In most cases, B. pyogenes infections are described in patients reporting close contact with animals (e.g., bites, licks), confirming that direct contact with animals should be considered the main route of transmission of B. pyogenes. Except for the case report by Chen and colleagues describing an infection after a snow leopard bite [23], in all other cases the contact with companion animals (cats and dogs) seems to be the main route of transmission (Table 1 and Table 2). This phenomenon may be linked to the closer contact between companion animals and humans. Nevertheless, in some cases B. pyogenes infections seem to be unrelated to animal bites, where contact with animals is not documented in the medical history of the patient or did not occur (Table 1 and Table 2). Minor scratches and bites caused by pets are not always reported to the healthcare facility.
Previous studies on Pasteurella multocida, a facultative anaerobic Gram-negative coccobacillus present in the oral and respiratory tracts of cats and dogs, hypothesized that the contamination of a wound with animal fluids or animal air, as well as the ingestion of food contaminated by the animal, may be associated with the onset of opportunistic infections, particularly in patients with comorbidities or in treatment with immunosuppressant [31]. For this reason, future studies on B. pyogenes are required to investigate potential transmission mechanisms other than animals’ bites.
Most references describe polymicrobial infections between B. pyogenes and other pathogens (Table 2 and Table 3). When more pathogens are detected, the specific contribution of B. pyogenes in the development of the infection cannot be conclusively assessed. Anaerobic bacteria, such as Fusobacterium spp. and Pasteurella spp., are among the coinfecting pathogens most frequently identified. In particular, P. multocida is considered responsible for skin and soft tissue infections, but it can be more rarely associated with severe infections such as bone and joint prosthesis infections, endocarditis, sepsis, and meningitis, particularly in immunocompromised hosts [32,33].
Table 3. Laboratory features of Bacteroides pyogenes infections reported in the literature, including type of infection, identification method used, antimicrobial susceptibility, and co-pathogens isolated.

3.3. Pathogenesis of B. pyogenes Infections

Despite the clinical significance of B. pyogenes infections, the mechanisms underlying its pathogenicity remain poorly understood. Usually, limited superficial soft tissue infections and abscesses are reported among healthy individuals. However, immunocompromised patients or those with important comorbidities may develop severe and/or systemic infections.
The pathogenicity of Bacteroides spp. includes the presence of a polysaccharide capsule, release of lipopolysaccharide, evasion of host immune response, production of proteolytic enzymes and hemolysin, release of enterotoxin, and aerotolerance [2]. Limited data on specific virulence factors of B. pyogenes are currently available; however, its ability to thrive in anaerobic conditions and cause systemic infections suggests the presence of mechanisms helping tissue invasion and immune evasion. B. pyogenes produces metabolic products such as succinic acid and acetic acid, which are thought to contribute to its survival in the anaerobic environments of host tissues [34]. It also demonstrates resistance to several host defense mechanisms, including phagocytosis by immune cells. The exact role of B. pyogenes in biofilm formation, a critical factor for chronic infection, needs to be better investigated [35]. Furthermore, there is evidence suggesting that B. pyogenes may harbor genetic elements conferring resistance to certain antimicrobial agents, complicating treatment regimens.

3.4. Diagnosis of B. pyogenes in Humans

Pre-analytical and analytical phases are crucial for guaranteeing the isolation of anaerobic bacteria, including B. pyogenes. Anaerobic infections may be underestimated because of difficulties related to their isolation and identification. Similarly to Pasteurella spp., B. pyogenes should be considered a potential etiological agent of soft tissue infections resulting from scratching, biting, or licking by domestic animals [31].
Proper sample collection is essential and should ideally be performed before the start of antibiotic therapy. Specimens must be free from contamination with commensal microbiota and representative of the infection site (aspirates and tissue biopsies should be preferred to swabs). All samples should be deeply inserted into anaerobic transport media or collected directly in oxygen-free containers. The transport to the laboratory should be at room temperature within two hours from the collection [36].

3.4.1. Identification of B. pyogenes

Diagnosis of B. pyogenes infection in clinical specimens can be achieved by isolating the pathogen from a culture or using molecular methods.
For culture-based methods, it is essential to provide appropriate conditions for the isolation of anaerobic bacteria, both in terms of culture medium and incubation environment. Specimens should be adequately inoculated on specific culture media, for example, Columbia Agar or Schaedler agar with 5% sheep blood and incubated for 48–72 h in anaerobic conditions (e.g., using anaerobic pouches, boxes, or jars) [3,36].
Table 4 summarizes the methods used for the identification of B. pyogenes in previously published reports. The identification of B. pyogenes with traditional biochemical methods may be inaccurate due to phenotypically similar species. Indeed, prior to the implementation of MALDI-TOF MS and 16S rRNA sequencing in diagnostics of bacterial infections, the identification of anaerobic microorganisms, such as B. pyogenes, was performed using biochemical methods, such as the VITEK-2 ANC card (bioMérieux, Marcy l’Etoile, France) or API Rapid ID 32A (bioMérieux, Marcy l’Etoile, France). Erroneous results of biochemical tests may be responsible for misidentification of the microorganism: Prevotella oralis and Prevotella melaninogenica were among the species more frequently misidentified [18,21,28,29] (Table 4).
Table 4. Methods used for Bacteroides pyogenes identification previously reported in the literature.
The introduction of MALDI-TOF MS and 16S rRNA sequencing in clinical microbiology laboratories may be partially responsible for the increasing number of reports of B. pyogenes infections in last years. The accuracy of MALDI-TOF MS [37] and 16S rRNA gene sequencing [38] to correctly identify anaerobic microorganisms has been widely demonstrated (Table 4). Both techniques have shown good performance in the identification of B. pyogenes [3,13,18,21,22,23,24,25,27,28,29], but MALDI-TOF MS is more frequently used in routine diagnostics because of its rapidity and reduced costs. However, to provide a correct identification of all microorganisms [36] and, in particular B. pyogenes [27,29], it is fundamental to maintain updated databases of identification instruments. Data libraries for anaerobes should include reference strains as well as clinical isolates corroborated by sequencing methods [36]. Park and colleagues reported a misidentification of B. pyogenes with B. uniformis using Vitek MS (bioMérieux, Marcy l’Etoile, France) (Table 3 and Table 4) [27].

3.4.2. Antimicrobial Susceptibility of B. pyogenes

Culture-based methods are fundamental to guaranteeing the execution of antimicrobial susceptibility testing. Drug susceptibility testing of B. pyogenes isolates should be performed according to the most recent International Guidelines of European Committee on Antimicrobial Susceptibility Testing (EUCAST) [39] or the Clinical & Laboratory Standards Institute (CLSI) [40]. The current version of EUCAST Guidelines, version 15.0, provides indications for the interpretation of the results of susceptibility testing of B. pyogenes for ampicillin–sulbactam, amoxicillin–clavulanic acid, piperacillin–tazobactam, ertapenem, imipenem, meropenem, clindamycin, and metronidazole, while the use of CLSI criteria offers the possibility to report results of other molecules; for example, moxifloxacin. Moreover, EUCAST Guidelines for the interpretation of amoxicillin–clavulanic acid were first published in Version 13.1 in June 2023. For this reason, most of the studies currently available interpret their results using CLSI criteria.
The use of different international guidelines with different antibiotic breakpoints for the interpretation of antimicrobial susceptibility testing makes the comparison of results between studies difficult. As reported in Table 3 and Table 5, data on antimicrobial susceptibility testing are not always clearly reported. However, in most of the cases, EUCAST criteria were used for the interpretation of the results (n = 13) [3], while CLSI criteria were used in five cases [17,22,28,29] and EUCAST with CLSI (for amoxicillin–clavulanate and moxifloxacin) were applied in eight cases [13,19,20]. In three cases, no indication of the criteria used for the interpretation of the results of antimicrobial susceptibility testing were reported [21,24,26].
Table 5. Antimicrobial susceptibility testing results of Bacteroides pyogenes infections reported in the literature.
Antibiotic resistance among Bacteroides spp. has increased over the past decade [36,41]. Unlike other Bacteroides spp., B. pyogenes has been shown to be highly susceptible to most of the molecules usually tested. Cunha and colleagues, in their study on B. pyogenes strains from the uteri of cows with metritis, described the presence of a beta-lactam resistance gene (cfxA2) in the four isolated tested. Moreover, they observed the presence of the tetQ gene, encoding for a ribosomal protection protein conferring resistance to tetracycline, and the sul2 gene, encoding for a dihydropteroate synthase type-2 and imparting sulfonamide resistance in some of the isolates [8]. Moreover, a study on the genomics of isolates belonging to the B. fragilis group excluded the presence of overexpression of the cfiA gene in B. pyogenes. The cfiA gene, responsible for carbapenem resistance, was, however, present in some of the B. fraglis isolates tested [42].
As described in Table 5, metronidazole, amoxicillin–clavulanate, and clindamycin were the antibiotics whose activity was most frequently tested against B. pyogenes strains. In most of the cases, beta-lactams associated with beta-lactamase inhibitors, carbapenems, clindamycin, and metronidazole demonstrated good in vitro activity against most B. pyogenes isolates (Table 5) [3,13,21,22,24]. Moreover, B. pyogenes showed a good susceptibility to penicillins [22,26], even though all seven isolates identified by Majewska and colleagues were found to be resistant [3].

4. Treatment and Outcomes of B. pyogenes Infections

Given the susceptibility of B. pyogenes to many classes of antimicrobials, the treatment of infections is often based on beta-lactams, such as amoxicillin–clavulanate, piperacillin–tazobactam and ceftriaxone, and/or metronidazole (Supplementary Table S1). The selection of the appropriate regimen of treatment should take into account the outcome of antimicrobial susceptibility testing, while the duration should be evaluated based on the site of the infection and response to the treatment. Moreover, in most cases, B. pyogenes was co-isolated with other pathogens, further hindering the selection of appropriate antibiotic therapy (Table 3).
Despite appropriate antimicrobial therapy, in the presence of animal bites and scratch-related infections, correct wound hygiene and close follow-up are fundamental to avoid complications. In particular, the adequate management of those infections requires the control of their focus. In addition to antimicrobial treatment, surgical procedures, such as incision or debridement, and hospitalization are frequently required to treat B. pyogenes infections and guarantee their favorable evolution (Table 2 and Supplementary Table S1).

5. Conclusions

The present narrative review summarizes the characteristics of infections by B. pyogenes in humans by gathering all the published articles in the PubMed literature.
B. pyogenes infections may affect any organ and system but mainly involve skin and soft tissues. In any wound resulting from an animal bite or scratch, primarily cats and dogs, anaerobes like B. pyogenes should be suspected as the causative agents of the infection. The contact with the saliva of the animal in the absence of a bite could be sufficient to allow infection with B. pyogenes. Careful medical history-taking and microbiological confirmation of the infection are essential for accurate diagnosis and choice of appropriate treatment.
The introduction of MALDI-TOF MS and 16S rRNA sequencing in clinical microbiology laboratories has allowed the identification of species of bacteria previously unassociated with human infections or rarely reported, such as B. pyogenes. Although B. pyogenes has been shown to be highly susceptible to most of the molecules usually tested in vitro except penicillin, antimicrobial susceptibility testing of the isolated strains is recommended. Despite the susceptibility to antibiotics, the treatment of infections caused by B. pyogenes often necessitates surgical procedures, hospitalization, and intravenous therapies. Meticulous monitoring of the infection’s progression is critical to ensure effective clinical management. While the pathogenic mechanisms of other Bacteroides spp. have been described, specific investigation on the pathogenic potential of B. pyogenes is still required to better understand the mechanisms underlying the development of infections caused by this microorganism.

Supplementary Materials

The following supporting information can be downloaded at: https://www.mdpi.com/article/10.3390/microorganisms13061200/s1, Supplementary Table S1: Clinical features of Bacteroides pyogenes infections reported in the literature, including age, gender, clinical presentation, underlying illness and risk factors, medical history, contact with animals, treatment, and outcome.

Author Contributions

C.M. and C.G. equally contributed to this work. C.M. conceptualized the work. C.M. and C.G. analyzed literature data and drafted the manuscript. E.B., A.C., and E.M. performed the literature search and drafted the manuscript. F.L. and S.T. supervised the activities and revised the manuscript. All authors have read and agreed to the published version of the manuscript.

Funding

This research received no external funding.

Data Availability Statement

No new data were created or analyzed in this study. Data sharing is not applicable to this article.

Conflicts of Interest

The authors declare no conflicts of interest.

References

  1. Shin, J.H.; Tillotson, G.; MacKenzie, T.N.; Warren, C.A.; Wexler, H.M.; Goldstein, E.J.C. Bacteroides and Related Species: The Keystone Taxa of the Human Gut Microbiota. Anaerobe 2024, 85, 102819. [Google Scholar] [CrossRef]
  2. Wexler, H.M. Bacteroides: The Good, the Bad, and the Nitty-Gritty. Clin. Microbiol. Rev. 2007, 20, 593–621. [Google Scholar] [CrossRef]
  3. Majewska, A.; Kierzkowska, M.; Kawecki, D. What We Actually Know about the Pathogenicity of Bacteroides Pyogenes. Med. Microbiol. Immunol. 2021, 210, 157–163. [Google Scholar] [CrossRef]
  4. Rajilić-Stojanović, M.; De Vos, W.M. The First 1000 Cultured Species of the Human Gastrointestinal Microbiota. FEMS Microbiol. Rev. 2014, 38, 996–1047. [Google Scholar] [CrossRef] [PubMed]
  5. Benno, Y.; Watabe, J.; Mitsuoka, T. Bacteroides Pyogenes Sp. Nov., Bacteroides Suis Sp. Nov., and Bacteroides Helcogenes Sp. Nov., New Species from Abscesses and Feces of Pigs. Syst. Appl. Microbiol. 1983, 4, 396–407. [Google Scholar] [CrossRef]
  6. Jeon, S.J.; Cunha, F.; Ma, X.; Martinez, N.; Vieira-Neto, A.; Daetz, R.; Bicalho, R.C.; Lima, S.; Santos, J.E.P.; Jeong, K.C.; et al. Uterine Microbiota and Immune Parameters Associated with Fever in Dairy Cows with Metritis. PLoS ONE 2016, 11, e0165740. [Google Scholar] [CrossRef] [PubMed]
  7. Ovesen, A.L.; Riihimäki, M.; Båverud, V.; Pringle, M. Antimicrobial Susceptibility of Bacteroides Spp. from Clinical Samples from Horses. J. Equine Vet. Sci. 2016, 45, 46–52. [Google Scholar] [CrossRef]
  8. Cunha, F.; Jeon, S.J.; Jeong, K.C.; Galvão, K.N. Draft Genome Sequences of Bacteroides Pyogenes Strains Isolated from the Uterus of Holstein Dairy Cows with Metritis. Microbiol. Resour. Announc. 2019, 8, e01043-19. [Google Scholar] [CrossRef]
  9. Forsblom, B.; Love, D.N.; Sarkiala–Kessel, E.; Jousimies–Somer, H. Characterization of Anaerobic, Gram-Negative, Nonpigmented, Saccharolytic Rods from Subgingival Sites in Dogs. Clin. Infect. Dis. 1997, 25, S100–S106. [Google Scholar] [CrossRef][Green Version]
  10. Sakamoto, M.; Suzuki, N.; Benno, Y. Hsp60 and 16S rRNA Gene Sequence Relationships among Species of the Genus Bacteroides with the Finding That Bacteroides Suis and Bacteroides Tectus Are Heterotypic Synonyms of Bacteroides Pyogenes. Int. J. Syst. Evol. Microbiol. 2010, 60, 2984–2990. [Google Scholar] [CrossRef]
  11. Sakamoto, M.; Oshima, K.; Suda, W.; Kitamura, K.; Iida, T.; Hattori, M.; Ohkuma, M. Draft Genome Sequences of Three Strains of Bacteroides Pyogenes Isolated from a Cat and Swine. Genome Announc. 2014, 2, e01242-13. [Google Scholar] [CrossRef]
  12. Jean, S.; Wallace, M.J.; Dantas, G.; Burnham, C.-A.D. Time for Some Group Therapy: Update on Identification, Antimicrobial Resistance, Taxonomy, and Clinical Significance of the Bacteroides Fragilis Group. J. Clin. Microbiol. 2022, 60, e02361-20. [Google Scholar] [CrossRef] [PubMed]
  13. Fernández Vecilla, D.; Urrutikoetxea Gutiérrez, M.J.; Roche Matheus, M.P.; Angulo López, I.; Aspichueta Vivanco, C.; Calvo Muro, F.E.; Díaz De Tuesta Del Arco, J.L. Description of Eight Human Infections Caused by Bacteroides Pyogenes in a Tertiary Hospital of Northern Spain. Anaerobe 2023, 82, 102759. [Google Scholar] [CrossRef] [PubMed]
  14. Love, D.N.; Johnson, J.L.; Moore, L.V.H. Bacteroides Species from the Oral Cavity and Oral-Associated Diseases of Cats. Vet. Microbiol. 1989, 19, 275–281. [Google Scholar] [CrossRef] [PubMed]
  15. Statista. Available online: https://www.statista.com/statistics/414956/dog-population-european-union-eu-by-country/ (accessed on 25 February 2025).
  16. Statista. Available online: https://www.statista.com/statistics/515410/cat-population-european-union-eu-by-country/ (accessed on 25 February 2025).
  17. Sadhwani, S.; DiAngelis, D.; Brown, M.; Ferguson, C.; Angerett, N. Unique Presentation of an Intramuscular Abscess Caused by Bacteroides Pyogenes in the Setting of a Cat Bite: A Case Report. SAGE Open Med. Case Rep. 2024, 12, 2050313X231222217. [Google Scholar] [CrossRef]
  18. Goggin, K.P.; Beckmann, N.; Bettin, K.; Carrillo-Marquez, M.; Wood, J.; Arnold, S.R. Lemierre’s Syndrome Due to the Zoonotic Anaerobe Bacteroides Pyogenes: Case Report and Literature Review. J. Pediatr. Infect. Dis. Soc. 2021, 10, 886–888. [Google Scholar] [CrossRef]
  19. Vecilla, D.F.; Matheus, M.P.R.; Hidalgo, G.I.; De Tuesta Del Arco, J.L.D. Osteomyelitis Caused by Pasteurella Multocida and Bacteroides Pyogenes after Cat Bite. Eur. J. Clin. Microbiol. Infect. Dis. 2023, 42, 125–128. [Google Scholar] [CrossRef]
  20. Fernández Vecilla, D.; Oiartzabal Elorriaga, U.; Urrutikoetxea Gutiérrez, M.J.; Pérez Ramos, I.S.; Díaz De Tuesta Del Arco, J.L. Jaw Osteomielitis and Myositis Caused by Bacteroides Pyogenes. Anaerobe 2023, 79, 102670. [Google Scholar] [CrossRef]
  21. Gual-de-Torrella, A.; Suárez-Barrenechea, A.I.; Del Toro, M.D. Infección de prótesis articular por Peptostreptococcus canis y Bacteroides pyogenes. Enfermedades Infecc. Microbiol. Clínica 2019, 37, 347–348. [Google Scholar] [CrossRef]
  22. Madsen, I.R.; Justesen, U.S. Bacteremia with Bacteroides Pyogenes after a Cat Bite. J. Clin. Microbiol. 2011, 49, 3092–3093. [Google Scholar] [CrossRef]
  23. Chen, H.-L.; Wang, X.; Li, J.; Fu, D.; Zhang, Q.-T.; Zhao, W.-L.; Ma, Y.-X.; Qi, R. A Severe Case Associated with Mixed Infections of Pasteurella Multocida, Bacteroides Pyogenes and Fusobacterium Necrophorum Due to a Snow Leopard Bite: A Case Report. Clin. Microbiol. Infect. 2025, 31, 657–659. [Google Scholar] [CrossRef]
  24. Shenoy, P.A.; Vishwanath, S.; Nagaraj, R.T.; Banerjee, B.; Krishna, M.S. Diabetic Foot Infection with Bacteroides Pyogenes. J. Glob. Infect. Dis. 2021, 13, 186–188. [Google Scholar] [CrossRef] [PubMed]
  25. Takahashi, J.; Sato, T.; Kobayashi, N.; Sado, M.; Aung, M.S.; Kobayashi, N.; Fujii, S. Bacteroides Pyogenes Isolated from Appendiceal Abscess in a Patient without Animal Contact. New Microbes New Infect. 2021, 44, 100933. [Google Scholar] [CrossRef] [PubMed]
  26. Umemura, H.; Yamasaki, O.; Iwatsuki, K. A Cat Bite-Induced Skin Abscess Associated with Bacteroides Pyogenes, Identified by Mass Spectrometry. Eur. J. Dermatol. 2018, 28, 392–393. [Google Scholar] [CrossRef] [PubMed]
  27. Park, J.E.; Park, S.-Y.; Song, D.J.; Huh, H.J.; Ki, C.-S.; Peck, K.R.; Lee, N.Y. A Case of Bacteroides Pyogenes Bacteremia Secondary to Liver Abscess. Anaerobe 2016, 42, 78–80. [Google Scholar] [CrossRef]
  28. Kim, Y.; Yang, H.-S.; Oh, T.; Kim, M.; Lee, H. A Case of Bloodstream Infection of Bacteroides Pyogenes Identified by 16S rRNA, gyrB, and Hsp60 Gene Sequencing. Clin. Lab. 2016, 62, 1187–1189. [Google Scholar] [CrossRef]
  29. Lau, J.S.Y.; Korman, T.M.; Yeung, A.; Streitberg, R.; Francis, M.J.; Graham, M. Bacteroides Pyogenes Causing Serious Human Wound Infection from Animal Bites. Anaerobe 2016, 42, 172–175. [Google Scholar] [CrossRef]
  30. Lee, H.K.; Walls, G.; Anderson, G.; Sullivan, C.; Wong, C.A. Prolonged Bacteroides Pyogenes Infection in a Patient with Multiple Lung Abscesses. Respirol. Case Rep. 2024, 12, e01314. [Google Scholar] [CrossRef]
  31. Piorunek, M.; Brajer-Luftmann, B.; Walkowiak, J. Pasteurella Multocida Infection in Humans. Pathogens 2023, 12, 1210. [Google Scholar] [CrossRef]
  32. Runnstrom, M.; Hyde, R.; Shah, K. Pasteurella Multocida Prosthetic Joint Infection. IDCases 2018, 13, e00429. [Google Scholar] [CrossRef]
  33. Lopes Freitas, R.; Reis, F.; Ruiz Pena, E. Pasteurella Multocida Bacteremia in an Immunocompromised Patient With Esophageal Squamous Cell Carcinoma: A Case Report. Cureus 2024, 16, e75924. [Google Scholar] [CrossRef] [PubMed]
  34. Zafar, H.; Saier, M.H. Gut Bacteroides Species in Health and Disease. Gut Microbes 2021, 13, 1848158. [Google Scholar] [CrossRef] [PubMed]
  35. Markowska, K.; Szymanek-Majchrzak, K.; Pituch, H.; Majewska, A. Understanding Quorum-Sensing and Biofilm Forming in Anaerobic Bacterial Communities. Int. J. Mol. Sci. 2024, 25, 12808. [Google Scholar] [CrossRef] [PubMed]
  36. Nagy, E.; Boyanova, L.; Justesen, U.S. How to Isolate, Identify and Determine Antimicrobial Susceptibility of Anaerobic Bacteria in Routine Laboratories. Clin. Microbiol. Infect. 2018, 24, 1139–1148. [Google Scholar] [CrossRef]
  37. Alcalá, L.; Marín, M.; Ruiz, A.; Quiroga, L.; Zamora-Cintas, M.; Fernández-Chico, M.A.; Muñoz, P.; Rodríguez-Sánchez, B. Identifying Anaerobic Bacteria Using MALDI-TOF Mass Spectrometry: A Four-Year Experience. Front. Cell. Infect. Microbiol. 2021, 11, 521014. [Google Scholar] [CrossRef]
  38. Justesen, U.S.; Skov, M.N.; Knudsen, E.; Holt, H.M.; Søgaard, P.; Justesen, T. 16S rRNA Gene Sequencing in Routine Identification of Anaerobic Bacteria Isolated from Blood Cultures. J. Clin. Microbiol. 2010, 48, 946–948. [Google Scholar] [CrossRef]
  39. The European Committee on Antimicrobial Susceptibility Testing. Breakpoint Tables for Interpretation of MICs and Zone Diameters. Version 15.0. 2025. Available online: https://www.eucast.org (accessed on 24 February 2025).
  40. CLSI. M100, Performance Standards for Antimicrobial Susceptibility Testing, 35th ed.; Clinical and Laboratory Standards Institute: Wayne, PA, USA, 2025. [Google Scholar]
  41. Kierzkowska, M.; Majewska, A.; Szymanek-Majchrzak, K.; Sawicka-Grzelak, A.; Mlynarczyk, A.; Mlynarczyk, G. The Presence of Antibiotic Resistance Genes and Bft Genes as Well as Antibiotic Susceptibility Testing of Bacteroides Fragilis Strains Isolated from Inpatients of the Infant Jesus Teaching Hospital, Warsaw during 2007–2012. Anaerobe 2019, 56, 109–115. [Google Scholar] [CrossRef]
  42. Wallace, M.J.; Jean, S.; Wallace, M.A.; Burnham, C.-A.D.; Dantas, G. Comparative Genomics of Bacteroides Fragilis Group Isolates Reveals Species-Dependent Resistance Mechanisms and Validates Clinical Tools for Resistance Prediction. mBio 2022, 13, e03603-21. [Google Scholar] [CrossRef]
Disclaimer/Publisher’s Note: The statements, opinions and data contained in all publications are solely those of the individual author(s) and contributor(s) and not of MDPI and/or the editor(s). MDPI and/or the editor(s) disclaim responsibility for any injury to people or property resulting from any ideas, methods, instructions or products referred to in the content.

Article Metrics

Citations

Article Access Statistics

Journal Statistics
Multiple requests from the same IP address are counted as one view.
Download PDF
Comparative Genomics of Sigma Factors in Acidithiobacillia Sheds Light into the Transcriptional Regulatory Networks Involved in Biogeochemical Dynamics in Extreme Acidic Environments
Previous
The Role of TLR4 in Lung Epithelial Cell Injury Caused by Influenza Virus Combined with Staphylococcus aureus
Next