Clinical and laboratory features of Mycobacterium porcinum.
Recent molecular studies have shown Mycobacterium porcinum, recovered from cases of lymphadenitis in swine, to have complete 16S rDNA sequence identity and >70% DNA-DNA homology with human isolates within the M. fortuitum third biovariant complex. We identified 67 clinical and two environmental isolates of the M. fortuitum third biovariant sorbitol-negative group, of which 48 (70%) had the same PCR restriction enzyme analysis (PRA) profile as the hsp65 gene of M. porcinum (ATCC 33776(T)) and were studied in more detail. Most U.S. patient isolates were from Texas (44%), Florida (19%), or other southern coastal states (15%). Clinical infections included wound infections (62%), central catheter infections and/or bacteremia (16%), and possible pneumonitis (18%). Sequencing of the 16S rRNA gene (1,463 bp) showed 100% identity with M. porcinum ATCC 33776(T). Sequencing of 441 bp of the hsp65 gene showed four sequevars that differed by 2 to 3 bp from the porcine strains. Clinical isolates were positive for arylsulfatase activity at 3 days, nitrate, iron uptake, D-mannitol, i-myo-inositol, and catalase at 68 degrees C. They were negative for L-rhamnose and D-glucitol (sorbitol). Clinical isolates were susceptible to ciprofloxacin, sulfamethoxazole, and linezolid and susceptible or intermediate to cefoxitin, clarithromycin, imipenem, and amikacin. M. porcinum ATCC 33776(T) gave similar results except for being nitrate negative. These studies showed almost complete phenotypic and molecular identity between clinical isolates of the M. fortuitum third biovariant D-sorbitol-negative group and porcine strains of M. porcinum and confirmed that they belong to the same species. Identification of M. porcinum presently requires hsp65 gene PRA or 16S rRNA or hsp65 gene sequencing.
Wallace
Richard J
RJ
The Mycobacterial/Nocardia Research Laboratory, Department of Microbiology, The University of Texas Health Center, 11937 U.S. Highway 271, Tyler, TX 75708, USA. richard.wallace@uthct.edu
Brown-Elliott
Barbara A
BA
Wilson
Rebecca W
RW
Mann
Linda
L
Hall
Leslie
L
Zhang
Yansheng
Y
Jost
Kenneth C
KC
Brown
June M
JM
Kabani
Amin
A
Schinsky
Mark F
MF
Steigerwalt
Arnold G
AG
Crist
Christopher J
CJ
Roberts
Glenn D
GD
Blacklock
Zeta
Z
Tsukamura
Michio
M
Silcox
Vella
V
Turenne
Christine
C
D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D018834:Chaperonin 60; D018833:Chaperonins / Q000235:genetics; D004275:DNA, Ribosomal / Q000032:analysis; D006801:Humans; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009161:Mycobacterium / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D009164:Mycobacterium Infections / Q000382:microbiology / Q000503:physiopathology; D019907:Mycobacterium fortuitum / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D013552:Swine / Q000382:microbiology*
D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018834:Chaperonin 60; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; C074119:heat-shock protein 65, Mycobacterium; D018833:Chaperonins