Mini Review ARTICLE
Identification and significance of Weissella species infections
- 1Clinical Microbiology Laboratory, Department of Pathology, The Ohio State University Wexner Medical Center, Columbus, OH, USA
- 2Department of Internal Medicine, Division of Infectious Diseases, The Ohio State University Wexner Medical Center, Columbus, OH, USA
Weissella spp. are non-spore forming, catalase-negative, gram-positive coccobacilli. They are often misidentified by traditional and commercial phenotypic identification methods as Lactobacillus spp. or Lactobacillus-like organisms. Weissella spp. were previously grouped along with Lactobacillus spp., Leuconostoc spp., and Pediococcus spp. Utilization of more sensitive methods like DNA sequencing or Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry (MALDI-TOF MS) has facilitated identification of Weissella as a unique genus. Nineteen species have been identified to date. W. confusa, W. cibaria, and W. viridescens are the only species isolated from humans. The true prevalence of Weissella spp. continues to be probably underestimated. Weissella spp. strains have been isolated from a wide range of habitats including raw milk, feces, fermented cereals, and vegetables. Weisella is believed to be a rare cause of usually nonfatal infections in humans, and is often considered a contaminant. However, in recent years, Weissella spp. have been implicated in bacteremia, abscesses, prosthetic joint infections, and infective endocarditis. Alterations of the gut flora from surgery or chemotherapy are believed to facilitate translocation of Weissella spp. due to disruption of the mucosal barrier, predisposing the host to infection with this organism. Implications of the isolation of Weissella spp. from blood must be interpreted in context of underlying risk factors. Weissella spp. are inherently resistant to vancomycin. Therefore, early consideraton of the pathogenic role of this bacteria and choice of alternate therapy is important to assure better outcomes.
Weissella spp. are non-spore forming, hetero-fermentative, facultative anaerobic, gram-positive, catalase-negative, alpha hemolytic bacteria that appear as short rods or coccobacilli in pairs and chains (Collins et al., 1993; Olano et al., 2001; Björkroth et al., 2009). Based on their unusual Gram stain morphology and inherent resistance to vancomycin, Weissella spp. have been often confused with Lactobacillus spp. or Lactobacillus-like organisms. They are usually considered contaminants when recovered from clinical specimens and rarely identified to the species level due to their fastidious nature (Facklam et al., 1989; Facklam and Elliott, 1995; Kumar et al., 2011).
Weissella was identified as a unique genus in 1993 on the basis of 16S rRNA gene sequence analysis and named after Norbert Weiss, a German microbiologist, for his many contributions to the taxonomy of lactic acid bacteria (Collins et al., 1993). Leuconostoc paramesenteroides and related species amongst the catalase-negative, vancomycin-resistant, gram-positive cocci were reclassified into this genus. Weissella now constitute a distinct phylogenetic group, separate from those of other genera of lactic acid bacteria, including Leuconostoc, Lactobacillus, and Streptococcus (Flaherty et al., 2003). To date, nineteen species of Weissella have been identified, namely: W. beninensis, W. ceti, W cibaria, W. confusa, W. diestrammenae, W. fabalis, W. fabaria, W. ghanensis, W. halotolerans, W. hellenica, W. kandleri, W. koreensis, W. minor, W. oryzae, W. paramesenteroides, W. soli, W. thailandensis, W. uvarum, W. viridescens (Fusco et al., 2015). All species except W. beninensis are non-motile (Padonou et al., 2010; Björkroth et al., 2014). Of these, only W. confusa (previously Lactobacillus confusus), W. cibaria, and W. viridescens have been isolated from human clinical specimens (Björkroth et al., 2002; Kulwichit et al., 2007; Fusco et al., 2015) and considered as opportunistic pathogens (Fusco et al., 2015). W. confusa has also been documented as a cause of systemic infection in a healthy primate (Cercopitheus mona; Vela et al., 2003) and neonatal sepsis in a foal (Lawhon et al., 2014). W. confusa and W. cibaria both have the ability to produce NH3 from arginine but differ in their ability to acidify different sugars (Björkroth et al., 2002). Unlike W. confusa, W. cibara is negative for the fermentation of galactose and xylose and positive for the fermentation of arabinose (Björkroth et al., 2002). Several species of Weissella, including some strains of W. confusa, can grow at 25, 35, and 45°C (Olano et al., 2001; Vasquez et al., 2015). Weissella species have been used in the production of a variety of fermented foods and beverages and also as probiotics (Kang et al., 2011; Lee et al., 2012; Gomathi et al., 2014; Zhang et al., 2014). W. cibaria possesses anti-cancer, anti-inflammatory, antibacterial, anti-fungal, and immune boosting potential (Nam et al., 2002; Kang et al., 2006; Srionnual et al., 2007; Lee et al., 2008, 2013; Valerio et al., 2009; Ahn et al., 2013; Kwak et al., 2014).
Weissella spp. have a widespread distribution and have been isolated from a wide variety of habitats including raw milk, feces, saliva, breast milk, urine, fermented cereals, meat and meat products, sugar cane, carrot juice, banana leaves and vegetables (Kandler and Weiss, 1986; Björkroth et al., 2002; Fairfax et al., 2014; Fusco et al., 2015). They have also been recovered from feces of healthy individuals (Green et al., 1990; Walter et al., 2001) and are common inhabitants of the vaginal microbiota (Jin et al., 2007). Although Weissella are of rare occurrence in humans, several disease outbreaks involving W. ceti have been reported in cultured rainbow trout from geographically diverse locations (United States, China, Brazil; Liu et al., 2009; Figueiredo et al., 2012; Welch and Good, 2013; Costa et al., 2015). The true incidence of Weissella infection in humans is probably underestimated due to its misidentification.
Identification of Weissella at the genus and species level has been challenging. It is often misidentified as Lactobacillus-like or viridans streptococci and accurate identification is not possible by traditional or commercial phenotypic identification methods that include morphological analysis, growth characteristics and sugar fermentation profiles as these techniques have low taxonomic discrimination (Fusco et al., 2015). Commercial biochemical based identification kits namely API (Analytical Profile Index systems, bioMéreiux, France) and RapiID Strep panel (Remel, USA) are unable to identify Weissella species. The identification table of API 20 Strep does not include Weissella. API 50 CHL kit (version 5.1) has W. confusa and W. viridescens in its identification table; however, it cannot differentiate W. cibara from W. confusa (Kulwichit et al., 2007). RapID™ STR System does include W. confusa in its database but only give a high probability result (Fairfax et al., 2014). Automated systems namely Vitek 2 (bioMéreiux, France), MicroScan (Beckman Coulter Inc. USA), and Phoenix Automated Microbiology System (BD Diagnostic Systems, USA), do not have Weissella in their database and as such cannot reliably identify Weissella species (Lee et al., 2011; Fairfax et al., 2014; Fusco et al., 2015).
Molecular DNA sequencing involving 16S rRNA gene sequence analysis can accurately identify Weissella to the species level and remains the current gold standard. It has also emerged as powerful tool for identification of phenotypically atypical microorganisms (Petti et al., 2005) and has been successfully used to identify Weissella to the species level (Collins et al., 1993; Vasquez et al., 2015). Most of the cases of W. confusa reported were originally misidentified as Lactobacillus-like or viridians streptococci organisms by phenotypic methods. These were subsequently confirmed to be W. confusa using 16S rRNA gene sequence analysis. Amplified ribosomal DNA restriction analysis (ARDRA; Jang et al., 2002) and ribotyping (Björkroth et al., 2002) have also been used to correctly identify Weissella species. Molecular typing techniques for Weissella species include DNA finger printing and restriction of ribosomal DNA (Villani et al., 1997), numerical analysis of HindIII and EcoRI ribopatterns (Koort et al., 2006), repetitive element-PCR fingerprinting using (GTG)5-PCR (Bounaix et al., 2010), and fluorescent- amplified fragment length polymorphism (fAFLP; Fusco et al., 2011). MALDI-TOF MS is now being routinely used for the identification of bacterial organisms (Bizzini et al., 2010; Wieser et al., 2012) and can also accurately identify W. confusa (Lee et al., 2013; Fairfax et al., 2014). Two MALDI-TOF MS systems have found increasing use in microbiology laboratories and both are sensitive for the identification of unusual and/or difficult-to-identify microorganisms isolated from clinical specimens (McElvania TeKippe and Burnham, 2014). The Bruker Biotyper (Bruker Daltonics, Germany) software version 3.0 also includes W. confusa, W. halotolerans, W. minor, and W. viridescens, and VITEK MS (bioMérieux, France) database v2.0 has W. confusa and W. viridescens. The future versions of both these mass spectrometry systems are likely to incorporate other Weissella spp. which will facilitate their early identification and provide insight into the true prevalence of these infections.
Predisposing Factors and Clinical Manifestations
Most of the cases of W. confusa infections reported in humans have been from immunocompromised patients (Lahtinen et al., 2012; Fairfax et al., 2014; Medford et al., 2014). Malignancy has been the most common factor associated with immunocompromised and complicated medical status. Recent chemotherapy, organ transplant, burn, chronic alcoholism, long-term use of steroids, chronic renal insufficiency and diabetes seem to increase the chances of acquiring this infection (Flaherty et al., 2003; Salimnia et al., 2011; Table 1). Orthopedic procedures like joint replacements, arthroplasty, and post-operative osteomyelitis also put the patients at increased risk of bacterial infections. Prior exposure to vancomycin may results in the selection of Weissella, which is intrinsically resistant to this drug. Central line catheter insertion prior to any surgical procedure increases the risk of infection, although Weissella has not been recovered from catheter tips. Total parenteral nutrition has been suspected to be risk factor for the development of bacteremia involving Weissella species (Olano et al., 2001; Flaherty et al., 2003; Kumar et al., 2011; Lee et al., 2011; Vasquez et al., 2015). Weissella is a common inhabitant of the human gastrointestinal system. A compromise of the gastrointestinal mucosal barrier due to surgery is associated with increased risk of acquiring this infection and may be a probable route of entry of W. confusa resulting in bacteremia and endocarditis (Flaherty et al., 2003; Shin et al., 2007). Polymicrobial infection and subsequent antimicrobial measures resulting in the alteration of gut flora also favor the selection of Weissella in such patients (Kumar et al., 2011). Changes in the normal flora of the throat, gut, and vaginal tract and disruption of mucous integrity by invasive procedures, surgery, and/or antibiotics predispose the host to increased risk of Weissella infection. The possible risk factors for W. cibara and W. viridescens infection in humans remain unknown.
W. confusa has been associated with a variety of clinical manifestations in humans (Table 1). The majority of the cases are seen in the settings of polymicrobial infections (Green et al., 1990, 1991; Bantar et al., 1991; Salimnia et al., 2011). However, it has also been recovered as the sole microbial agent in certain cases (Flaherty et al., 2003; Lee et al., 2011). Bacteremia is the major manifestation of W. confusa infection in humans (Olano et al., 2001; Kulwichit et al., 2007; Svec et al., 2007; Harlan et al., 2011; Lee et al., 2011, 2013; Salimnia et al., 2011; Vasquez et al., 2015). Other clinical vignettes in which this organism has been reported include endocarditis (Flaherty et al., 2003; Shin et al., 2007), post-operative osteomyelitis (Kulwichit et al., 2008), and abscess (Bantar et al., 1991). It has also been recovered from peritoneal fluid and the abdominal wall (Riebel and Washington, 1990) and infected prosthetic joint (Medford et al., 2014).
W. cibaria have been identified in the urine, lung, and blood of patients with bacteremia. W. viridescens has been recovered from human blood (Kulwichit et al., 2007) and fecal DNA from children with celiac disease (Sanz et al., 2007). The clinical significance of infections with these species is not yet clear.
Antimicrobial Susceptibility Testing
Weissella is known to be intrinsically resistant to vancomycin and has high minimum inhibitory concentration (MIC) of ≥256 μg/ml. Antimicrobial susceptibilities of W. confusa are not fully understood. There are no standard methods and interpretation criteria of antimicrobial susceptibilities established so far for Weissella spp. by the Clinical and Laboratory Standards Institute (CLSI). Susceptibility testing methods have included broth dilution, agar based methods (Bantar et al., 1991; Olano et al., 2001; Vay et al., 2007; Lee et al., 2011; Medford et al., 2014) and E-test (Svec et al., 2007; Table 2). Low MICs have been noted for penicillin, ampicillin, tetracycline, clindamycin, erythromycin, ciprofloxacin, daptomycin, imipenem, fluoroquinolones (levofloxacin, moxifloxacin), amoxicillin-clavulanate, ampicillin-sulbactam, piperacillin-tazobactam, and doripenem. W. confusa exhibits a high level of resistance to ceftazidime, cotrimoxazole, rifampin, metronidazole, teicoplanin and trimethoprim/sulfamethoxazol.
Table 2. Minimum Inhibitory Concentrations (MICs, in μg/mL) of Weissella confusa to various antibiotics.
W. confusa is an opportunistic bacterial organism that warrants rapid and accurate identification to ensure appropriate therapy. It is difficult to distinguish Weissella species from other heterofermentative bacteria on the basis of phenotypic or biochemical tests alone. Accurate and rapid identification to the species level is feasible using 16S rRNA or MALDI-TOF MS techniques. Infections with Weissella spp. primarily occur in immunocompromised status and/or those with other underlying medical conditions. It is a common inhabitant of the gut flora, therefore, surgical procedures may translocate this organism and result in bacteremia, endocarditis, and abscess formation. The clinical significance of W. confusa remains unclear in the setting of polymicrobial infections, which comprise the largest proportion of total cases. The use of antimicrobial agents, especially vancomycin, may predispose patients to increased risk of infection with Weissella, which is intrinsically resistant to this drug (Lahtinen et al., 2012; Fairfax et al., 2014; Medford et al., 2014). When isolated in blood culture, Weissella may be confused with Lactobacillus-like or viridians streptococci and can be considered a probable contaminant (Ruoff, 2002; Fairfax and Salimnia, 2012; Fairfax et al., 2014). However, Weissella is not a part of the normal skin flora and should be considered significant when isolated from blood cultures (Petti et al., 2005).
Vancomycin is the empiric first-line therapy for bacteremia caused by gram-positive organisms. However, the use of vancomycin is likely to favor the growth of vancomycin-resistant organisms and may predispose these patients to subsequent infections with Weissella and other vancomycin resistant organisms (Fairfax and Salimnia, 2012). Early consideration of this organism in the differential diagnosis is important due to its inherent vancomycin resistance, which necessitates alternative therapy. Management of positive blood cultures especially from immunocompromised patients is a challenge both for the laboratory microbiologists as well as the clinicians. Penicillin, ampicillin, imipenem, clindamycin, erythromycin, moxifloxacin, doripenem, daptomycin, and tigecycline are all therapeutic agents for treating Weissella infections. The use of vancomycin, metronidazole, rifampin, teicoplanin, ceftazadime, and trimethoprim-sulphamethoxazole should be avoided if Weissella spp. is suspected. Antimicrobial susceptibility testing is vital to guide appropriate therapy in cases of severe infections.
Conflict of Interest Statement
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
Ahn, S. B., Park, H. E., Lee, S. M., Kim, S. Y., Shon, M. Y., and Lee, W. K. (2013). Characteristics and immuno-modulatory effects of Weissella cibaria JW15 isolated from Kimchi, Korea traditional fermented food, for probiotic use. J. Biomed. Res. 4, 206–211. doi: 10.12729/jbr.2013.14.4.206
Bizzini, A., Durussel, C., Bille, J., Greub, G., and Prod'hom, G. (2010). Performance of matrix-assisted laser desorption ionization-time of flight mass spectrometry for identification of bacterial strains routinely isolated in a clinical microbiology laboratory. J. Clin. Microbiol. 48, 1549–1554. doi: 10.1128/JCM.01794-09
Björkroth, J. A., Dicks, L. M. T. D., and Endo, A. (2014). “The genus Weissella,” in Lactic Acid Bacteria, Biodiversity and Taxonomy, eds W. H. Holzapfel and B. J. B. Wood (Chichester: Wiley Blackwell), 418–428. doi: 10.1002/9781118655252.ch25
Björkroth, J. A., Dicks, L. M. T. D., and Holzapfel, W. H. (2009). “Genus III. Weissella Collins, Samelis, Metaxopoulos and Wallbanks 1994, 370VP (Effective publication: Collins, Samelis, Metaxopoulos, and Wallbanks 1993, 597),” in Bergey's Manual of Systematic Bacteriology, 2nd Edn., Vol. 3. The Firmicutes, eds P. de Vos, G. M. Garrity, D. Jones, N. R. Krieg, W. Ludwig, F. A. Rainey, et al. (New York, NY: Springer), 643–654.
Björkroth, K. J., Schillinger, U., Geisen, R., Weiss, N., Hoste, B., Holzapfel, W. H., et al. (2002). Taxonomic study of Weissella confusa and description of Weissella cibaria sp. nov., detected in food and clinical samples. Int. J. Syst. Evol. Microbiol. 52, 141–148. doi: 10.1099/00207713-52-1-141
Bounaix, M. S., Robert, H., Gabriel, V., Morel, S., Remaud-Siméon, M., Gabriel, B., et al. (2010). Characterization of dextran-producing Weissella strains isolated from sourdoughs and evidence of constitutive dextransucrase expression. FEMS Microbiol. Lett. 311, 18–26. doi: 10.1111/j.1574-6968.2010.02067.x
Collins, M. D., Samelis, J., Mataxapoulos, J., and Wallbanks, S. (1993). Taxonomic studies on some leoconostoc-like organisms from fermented sausages: description of a new genus Weissella for the Leuconostoc paramesenteroides group of species. J. Appl. Bacteriol. 75, 595–603. doi: 10.1111/j.1365-2672.1993.tb01600.x
Costa, F. A. A., Leal, C. A. G., Schuenker, N. D., Leite, R. C., and Figueiredo, H. C. P. (2015). Characterization of Weissella ceti infections in Brazilian rainbow trout, Oncorhynchus mykiss (Walbaum), farms and development of an oil-adjuvanted vaccine. J. Fish Dis. 38, 295–302. doi: 10.1111/jfd.12236
Facklam, R., and Elliott, J. A. (1995). Identification, classification, and clinical relevance of catalase-negative, gram-positive cocci, excluding the streptococci and enterococci. Clin. Microbiol. Rev. 8, 479–495.
Fairfax, M. R., Lephart, P. R., and Salimnia, H. (2014). Weissella confusa: problems with identification of an opportunistic pathogen that has been found in fermented foods and proposed as a probiotic. Front. Microbiol. 5:254. doi: 10.3389/fmicb.2014.00254
Figueiredo, H. C., Costa, F. A., Leal, C. A., Carvalho-Castro, G. A., and Leite, R. C. (2012). Weissella sp. outbreaks in commercial rainbow trout (Oncorhynchus mykiss) farms in Brazil. Vet. Microbiol. 156, 359–366. doi: 10.1016/j.vetmic.2011.11.008
Flaherty, J. D., Levett, P. N., Dewhirst, F. E., Troe, T. E., Warren, J. R., and Johnson, S. (2003). Fatal case of endocarditis due to Weissella confusa. J. Clin. Microbiol. 41, 2237–2239. doi: 10.1128/JCM.41.5.2237-2239.2003
Fusco, V., Quero, G. M., Cho, G. S., Kabisch, J., Meske, D., Neve, H., et al. (2015). The genus Weissella: taxonomy, ecology and biotechnological potential. Front. Microbiol. 6:155. doi: 10.3389/fmicb.2015.00155
Fusco, V., Quero, G. M., Stea, G., Morea, M., and Visconti, A. (2011). Novel PCR-based identification of Weissella confusa using an AFLP-derived marker. Int. J. Food Microbiol. 145, 437–443. doi: 10.1016/j.ijfoodmicro.2011.01.015
Gomathi, S., Sasikumar, P., Anbazhagan, K., Sasikumar, S., Kavitha, M., Selvi, M. S., et al. (2014). Screening of indigenous oxalate degrading lactic acid bacteria from human faeces and South Indian fermented foods: assessment of probiotic potential. Sci. World J. 2014:648059 doi: 10.1155/2014/648059
Harlan, N. P., Kempker, R. R., Parekh, S. M., Burd, E. M., and Kuhar, D. T. (2011). Weissella confusa bacteremia in a liver transplant patient with hepatic artery thrombosis. Transpl. Infect. Dis. 13, 290–293. doi: 10.1111/j.1399-3062.2010.00579.x
Jang, J., Kim, B., Lee, J., Kim, J., Jeong, G., and Han, H. (2002). Identification of Weissella species by the genus-specific amplified ribosomal DNA restriction analysis. FEMS Microbiol. Lett. 212, 29–34. doi: 10.1111/j.1574-6968.2002.tb11240.x
Jin, L., Tao, L., Pavlova, S. I., So, J.-S., Kiwanuka, N., Namukwaya, Z., et al. (2007). Species diversity and relative abundance of vaginal lactic acid bacteria from women in Uganda and Korea. J. Appl. Microbiol. 102, 1107–1115. doi: 10.1111/j.1365-2672.2006.03147.x
Kang, M. S., Chung, J., Kim, S. M., Yang, K. H., and Oh, J. S. (2006). Effect of Weissella cibaria isolates on the formation of Streptococcus mutans biofilm. Caries Res. 40, 418–425. doi: 10.1159/000094288
Kang, M. S., Lim, H. S., Kim, S. M., Lee, H. C., and Oh, J. S. (2011). Effect of Weissella cibaria on Fusobacterium nucleatum -induced interleukin-6 and interleukin-8 production in KB cells. J. Bacteriol. Virol. 41, 9–18. doi: 10.4167/jbv.2011.41.1.9
Koort, J., Coenye, T., Santos, E. M., Molinero, C., Jaime, I., Rovira, J., et al. (2006). Diversity of Weissella viridescens strains associated with “Morcilla de Burgos”. Int. J. Food Microbiol. 109, 164–168. doi: 10.1016/j.ijfoodmicro.2006.01.021
Kulwichit, W., Nilgate, S., Chatsuwan, T., Krajiw, S., Unhasuta, C., and Chongthaleong, A. (2007). Accuracies of Leuconostoc phenotypic identification: a comparison of API systems and conventional phenotypic assays. BMC Infect. Dis. 7:69. doi: 10.1186/1471-2334-7-69
Kulwichit, W., Nilgate, S., Krajiw, S., Unhasuta, C., Chatsuwan, T., and Chongthaleong, A. (2008). “Weissella spp.: lactic acid bacteria emerging as a human pathogen. Abstract number: P1847,” in 18th European Congress of Clinical Microbiology and Infectious Diseases (Barcelona).
Kumar, A., Augustine, D., Sudhindran, S., Kurian, A. M., Dinesh, K. R., Karim, S., et al. (2011). Weissella confusa: a rare cause of vancomycin-resistant Gram-positive bacteraemia. J. Med. Microbiol. 60, 1539–1541. doi: 10.1099/jmm.0.027169-0
Kwak, S. H., Cho, Y. M., Noh, G. M., and Om, A. S. (2014). Cancer preventive potential of Kimchi lactic acid bacteria (Weissella cibaria, Lactobacillus plantarum). J. Cancer Prev. 19, 253–258. doi: 10.15430/JCP.2014.19.4.253
Lahtinen, S., Ouwehand, A. C., Salminen, S., and Von Wright, A. (eds.). (2012). Lactic Acid Bacteria—Microbiological and Functional Aspects, 4th Edn. Boca Raton, FL: CRC Press; Taylor and Francis Group.
Lawhon, S. D., Lopez, F. R., Joswig, A., Black, H. C., Watts, A. E., Norman, T. E., et al. (2014). Weissella confusa septicemia in a foal. J. Vet. Diagn. Invest. 26, 150–153. doi: 10.1177/1040638713510516
Lee, I. H., Lee, S. H., Lee, I. S., Park, Y. K., Chung, D. K., and Choue, R. W. (2008). Effects of probiotic extracts of kimchi on immune function in NC/Nga mice. Korean J. Food Sci. Technol. 40, 82–87.
Lee, K. W., Park, J. Y., Jeong, H. R., Heo, H. J., Hans, N. S., and Kim, J. H. (2012). Probiotic properties of Weissella strains isolated from human faeces. Anaerobe 18, 96–102. doi: 10.1016/j.anaerobe.2011.12.015
Lee, M. R., Huang, Y. T., Liao, C. H., Lai, C. C., Lee, P. I., and Hsueh, P. R. (2011). Bacteremia caused by Weissella confusa at a university hospital in Taiwan, 1997-2007. Clin. Microbiol. Infect. 17, 1226–1231. doi: 10.1111/j.1469-0691.2010.03388.x
Lee, W., Cho, S. M., Kim, M., Ko, Y. -G., Yong, D., and Lee, K. (2013). Weissella confusa bacteremia in an immune-competent patient with underlying intramural hematomas of the aorta. Ann. Lab. Med. 33, 459–462. doi: 10.3343/alm.2013.33.6.459
Liu, J. Y., Li, A. H., Ji, C., and Yang, W. M. (2009). First description of a novel Weissella species as an opportunistic pathogen for rainbow trout Oncorhynchus mykiss (Walbaum) in China. Vet. Microbiol. 136, 314–320. doi: 10.1016/j.vetmic.2008.11.027
McElvania TeKippe, E., and Burnham, C. A. (2014). Evaluation of the bruker biotyper and VITEK MS MALDI-TOF MS systems for the identification of unusual and/or difficult-to-identify microorganisms isolated from clinical specimens. Eur. J. Clin. Microbiol. Infect. Dis. 33, 2163–2171. doi: 10.1007/s10096-014-2183-y
Medford, R., Patel, S. N., and Evans, G. A. (2014). A confusing case - Weissella confusa prosthetic joint infection: a case report and review of the literature. Can. J. Infect. Dis. Med. Microbiol. 25, 173–175.
Nam, H., Ha, M., Bae, O., and Lee, Y. (2002). Effect of Weissella confusa strain PL9001 on the adherence and growth of Helicobacter pylori. Appl. Environ. Microbiol. 68, 4642–4645. doi: 10.1128/AEM.68.9.4642-4645.2002
Olano, A., Chua, J., Schroeder, S., Minari, A., La Salvia, M., and Hall, G. (2001). Weissella confusa (basonym: Lactobacillus confusus) bacteremia: a case report. J. Clin. Microbiol. 39, 1604–1607. doi: 10.1128/JCM.39.4.1604-1607.2001
Padonou, S. W., Schillinger, U., Nielsen, D. S., Franz, C. M., Hansen, M., Hounhouigan, J. D., et al. (2010). Weissella beninensis sp. nov., a motile lactic acid bacterium from submerged cassava fermentations, and emended description of the genus Weissella. Int. J. Syst. Evol. Microbiol. 60, 2193–2198. doi: 10.1099/ijs.0.014332-0
Petti, C. A., Polage, C. R., and Schreckenberger, P. (2005). The role of v16 S rRNA gene sequencing in identification of microorganisms misidentified by conventional methods. J. Clin. Microbiol. 43, 6123–6125. doi: 10.1128/JCM.43.12.6123-6125.2005
Salimnia, H., Alangaden, G. J., Bharadwaj, R., Painter, T. M., Chandrasekar, P. H., and Fairfax, M. R. (2011). Weissella confusa: an unexpected cause of vancomycin-resistant gram-positive bacteremia in immunocompromised hosts. Transpl. Infect. Dis. 13, 294–298. doi: 10.1111/j.1399-3062.2010.00586.x
Sanz, Y., Sánchez, E., Marzotto, M., Calabuig, M., Torriani, S., and Dellaglio, F. (2007). Differences in faecal bacterial communities in coeliac and healthy children as detected by PCR and denaturing gradient electrophoresis. FEMS Immunol. Med. Microbiol. 51, 562–568. doi: 10.1111/j.1574-695X.2007.00337.x
Shin, J. H., Kim, D. I., Kim, H. R., Kim, D. S., Kook, J. K., and Lee, J. N. (2007). Severe infective endocarditis of native valves caused by Weissella confusa detected incidentally on electrocardiography. J. Infect. 54, 49–151. doi: 10.1016/j.jinf.2006.09.009
Srionnual, S., Yanagida, F., Lin, L. H., Hsiao, K. N., and Chen, Y. S. (2007). Weissellicin 110, a newly discovered bacteriocin from Weissella cibaria 110, isolated from plaa-som, a fermented fish product from Thailand. Appl. Environ. Microbiol. 73, 2247–2250. doi: 10.1128/AEM.02484-06
Svec, P., Sevcíková, A., Sedlácek, I., Bednárová, J., Cindy Snauwaert, C., Lefebvre, K., et al. (2007). Identification of lactic acid bacteria isolated from human blood cultures. FEMS Immunol. Med. Microbiol. 49, 192–196. doi: 10.1111/j.1574-695X.2006.00199.x
Valerio, F., Favilla, M., De Bellis, P., Sisto, A., de Candia, S., and Lavermicocca, P. (2009). Antifungal activity of strains of lactic acid bacteria isolated from a semolina ecosystem against Penicillium roqueforti, Aspergillus niger and Endomyces fibuliger contaminating bakery products. Syst. Appl. Microbiol. 32, 438–448. doi: 10.1016/j.syapm.2009.01.004
Vay, C., Cittadini, R., Barberis, C., Rodríguez, C. H., Martínez, H. P., Genero, F., et al. (2007). Antimicrobial susceptibility of non-enterococcal intrinsic glycopeptide-resistant Gram-positive organisms. Diag. Microbiol. Inf. Dis. 57, 183–188. doi: 10.1016/j.diagmicrobio.2006.08.014
Vela, A. I., Porrero, C., Goyache, J., Nieto, A., Sánchez, B., Briones, V., et al. (2003). Weissella confusa Infection in Primate (Cercopithecus mona). Emerging Infect. Dis. 9, 1307–1309. doi: 10.3201/eid0910.020667
Villani, F., Moschetti, G., Blaiotta, G., and Coppola, S. (1997). Characterization of strains of Leoconostoc mesenteroides by analysis of soluble whole cell protein patterns, DNA finger printing and restriction of ribosomal DNA. J. Appl. Microbiol. 82, 578–588. doi: 10.1111/j.1365-2672.1997.tb03588.x
Walter, J., Hertel, C., Tannock, G. W., Lis, C. M., Munro, K., and Hammes, W. P. (2001). Detection of Lactobacillus, Pediococcus, Leuconostoc, and Weissella species in human feces by using group-specific PCR primers and denaturing gradient gel electrophoresis. Appl. Environ. Microbiol. 67, 2578–2585. doi: 10.1128/AEM.67.6.2578-2585.2001
Welch, T. J., and Good, C. M. (2013). Mortality associated with Weissellosis (Weissella sp.) in USA farmed rainbow trout: potential for control by vaccination. Aquaculture 388–391, 122–127. doi: 10.1016/j.aquaculture.2013.01.021
Wieser, A., Schneider, L., Jung, J., and Schubert, S. (2012). MALDI-TOF MS in microbiological diagnostic-identification of microorganisms and beyond (min review). Appl. Microbiol. Biotechnol. 93, 965–974. doi: 10.1007/s00253-011-3783-4
Keywords: Lactobacillus spp., Weissella species, vancomycin resistance, MALDI-TOF MS
Citation: Kamboj K, Vasquez A and Balada-Llasat J-M (2015) Identification and significance of Weissella species infections. Front. Microbiol. 6:1204. doi: 10.3389/fmicb.2015.01204
Received: 31 August 2015; Accepted: 16 October 2015;
Published: 31 October 2015.
Edited by:Vincenzina Fusco, National Research Council of Italy - Institute of Sciences of Food Production, Italy
Reviewed by:Carmen Wacher, Universidad Nacional Autónoma de México, Mexico
Giuseppe Blaiotta, Dipartimento di Agraria, Italy
Copyright © 2015 Kamboj, Vasquez and Balada-Llasat. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Joan-Miquel Balada-Llasat, email@example.com