Characterization of Bacteroides forsythus Strains from Cat and Dog Bite Wounds in Humans and Comparison with Monkey and Human Oral Strains

Abstract

Bacteroides forsythus strains recovered from cat and dog bite wound infections in humans (n = 3), monkey oral strains (n = 3), and the human oral ATCC 43037 type strain were characterized by using phenotypic characteristics, enzymatic tests, whole cell fatty acid analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) analysis, PCR fingerprinting, and 16S rDNA (genes coding for rRNA) sequencing. All three bite wound isolates grew on brucella agar supplemented with 5% sheep blood, vitamin K1, and hemin. These strains, unlike the ATCC strain and previously described monkey oral and human clinical strains, did not require N-acetylmuramic acid supplementation for growth as pure cultures. However, their phenotypic characteristics, except for catalase production, were similar to those of previously identified strains. PCR fingerprinting analysis showed differences in band patterns from the ATCC strain. Also, SDS-PAGE and whole cell fatty acid analysis indicated that the dog and cat bite wound strains were similar but not identical to the human B. forsythus ATCC 43037 type strain and the monkey oral strains. The rDNA sequence analysis indicated that the three bite wound isolates had 99.93% homology with each other and 98.9 and 99.22% homology with the human ATCC 43037 and monkey oral strains, respectively. These results suggest that there are host-specific variations within each group.

Reclassification of Bacteroides forsythus (Tanner et al. 1986) as Tannerella forsythensis corrig., gen. nov., comb. nov.

“…The presence of trypsin activity is regarded as an important factor for tissue destruction in periodontal disease. In this study, B. forsythus strains (human oral isolates) were catalasenegative, whereas B. forsythus strains recovered from cat and dog bite wounds in humans were catalasepositive (Hudspeth et al, 1999). In addition, human oral isolates of B. forsythus were negative for indole production, whereas the monkey oral isolates and bitewound isolates were positive for indole production (Braham & Moncla, 1992 ;Hudspeth et al, 1999).…”

“…In this study, B. forsythus strains (human oral isolates) were catalasenegative, whereas B. forsythus strains recovered from cat and dog bite wounds in humans were catalasepositive (Hudspeth et al, 1999). In addition, human oral isolates of B. forsythus were negative for indole production, whereas the monkey oral isolates and bitewound isolates were positive for indole production (Braham & Moncla, 1992 ;Hudspeth et al, 1999). 16S rDNA sequence analysis indicated that the three bitewound isolates had 99n3 % similarity to each other and 98n9 and 99n22 % similarity, respectively, to the human strain B. forsythus ATCC 43037 T and monkey oral…”

“…1 2 n5 1 5 n9 8 n0 iso-3-OH-17 : 0 7n7 6 n4 7 n4 1 7 n7 1 2 n8 7 n0 9 n2 9 n7 7 n7 1 9 n2 2 3 n5 isolated from subgingival plaque samples from monkeys (Macaca fascicularis) also required NAM for growth. However, B. forsythus strains recovered from cat and dog bite-wound infections in humans did not require NAM for growth (Hudspeth et al, 1999). These results suggest that there are host-specific biotypes within the species B. forsythus.…”

“…Indole k k k k k j j j j k α-Glucosidase j j k j j j j j j j α-Arabinofuranosidase k   j j j k j j j β-Glucosidase j j k k j j j j j k α--Fucosidase j k k j j j j j j j α-Galactosidase k j j j j j k j j j Leucine aminopeptidase k j j k j k k j k k Proline aminopeptidase k k  k k k k k k k Pyroglutamic acid arylamidase k   k k k k k k k Arginine aminopeptidase j j j k j k k j k k Histidine aminopeptidase j j j k j k k j k k Phenylalanine aminopeptidase k   k k k k k k k Glycine aminopeptidase k j j k k k k k k j Catalase k j k k k j k j k k strains (Hudspeth et al, 1999). The high similarity ( 98n9 %) of 16S rDNA sequences from all the strains tested suggests that they belong to a single species ; however, DNA-DNA homology studies will be necessary for this to be confirmed.…”

“…B. forsythus was related to Bacteroides distasonis and Bacteroides merdae at about 88 and 91 % similarity, respectively. These data Data were taken from Braham & Moncla (1992), Collins et al (1994), Fournier et al (2001), Hirasawa & Takada (1994), Hudspeth et al (1999), Johnson (1978), Johnson et al (1986), Love (1995), Love et al (1992Love et al ( , 1994, Moore et al (1994), Shah & Collins (1988, 1989, Shah et al (1995), Tanner et al (1986), Willems & Collins (1995a, b) also agree with previous findings from 16S rRNA sequence analysis (Paster et al, 1994 ;Tanner et al, 1994). Although B. forsythus was related to B. distasonis and B. merdae, the ratio of anteiso-15 : 0 to iso-15 : 0 in whole-cell methanolysates of B. forsythus was different from those of B. distasonis and B. merdae.…”