Acid-Fast Serpentine Cords of Mycobacterium tuberculosis.
A 25-year-old man with a 2-month history of weight loss and night sweats complained of recent-onset left thigh pain and hyperesthesia hyperesthesia /hy·per·es·the·sia/ (-es-the´zhah) increased sensitivity to stimulation, particularly to touch.hyperesthet´ic
acoustic hyperesthesia , auditory hyperesthesia hyperacusis. . Radiologic investigation identified a large abscess within his left psoas psoas
a sublumbar muscle. See Table 13.
on the ventral border of the shaft of the ilium; attachment point for the psoas minor muscle. muscle that extended from the left renal vein to the inguinal region. A smaller fluid collection was also noted within the right psoas muscle. These lesions were accompanied by bony destruction and sequestration of the fourth lumbar vertebra. Purulent pu·ru·lent
Containing, discharging, or causing the production of pus.
Consisting of or containing pus
Mentioned in: Lacrimal Duct Obstruction
containing or forming pus. fluid was drained from the left abscess, from which oxacillin-sensitive Staphylococcus aureus was isolated. The patient was treated with oxacillin oxacillin /ox·a·cil·lin/ (ok?sah-sil´in) a semisynthetic penicillinase-resistant penicillin used as the sodium salt in infections due to penicillin-resistant, gram-positive organisms. , continuous pigtail drainage of the abscesses, and local debridement. Two weeks later, mycobacteria were recovered in culture from involved vertebral tissue. A Kinyoun-stained smear prepared from the BACTEC MGIT broth culture revealed serpentine cords (Figure 1). These ropelike aggregates consisted of numerous add-fast bacilli (Figure 2). DNA hybridization studies definitively identified these bacteria as being Mycobacterium tuberculosis complex. Cord formation in liquid media and fluid samples is a reliable and predictive marker for M tuberculosis, whereas nontuberculous mycobacteria tend to orient randomly.[1,2] The cord factor (trehalose tre·ha·lose
A sweet-tasting, crystalline disaccharide, C12H22O11, found in trehala and in many fungi. 6,6'-dimycolate) responsible for this morphological phenomenon contributes significantly to the virulence of M tuberculosis. These toxic surface glycolipids evoke cytokine-related host weight loss and play a fundamental role in the genesis and persistence of granulomas. The cord factor also inhibits phagocytosis phagocytosis: see endocytosis.
A mechanism by which single cells of the animal kingdom, such as smaller protozoa, engulf and carry particles into the cytoplasm. and hinders phagosome-lysosome fusion within activated host macrophages.
[1.] McCarter YS, Ratkiewicz IN, Robinson A. Cord formation in BACTEC medium is a reliable, rapid method for presumptive identification of Mycobacterium tuberculosis complex. J Clin Microbiol 1998;36:2769-2771.
[2.] Badak FZ, Goksel S, Sertoz R, Guzelant A, Kizirgil A, Bilgic A. Cord formation in MB/BacT medium is a reliable criterion for presumptive identification of Mycobacterium tuberculosis complex in laboratories with high prevalence of M. tuberculosis. J Clin Microbiol. 1999;37:4189-4191.
[3.] Behling CA, Bennett B, Takayama K, Hunter RL. Development of a trehalose 6,6'-dimycolate model which explains cord formation by Mycobacterium tuberculosis. Infect Immunol. 1993;61:2296-2303.
Accepted for publication March 15, 2001.
From the Department of Pathology, Beth Israel Deaconess Medical Center Both an international and regional referral center, Beth Israel Deaconess Medical Center (BIDMC) in Boston, Massachusetts is a major teaching hospital of Harvard Medical School. It was formed out of the 1996 merger of Beth Israel Hospital (founded in 1916) and , Harvard Medical School Harvard Medical School (HMS) is one of the graduate schools of Harvard University. It is a prestigious American medical school located in the Longwood Medical Area of the Mission Hill neighborhood of Boston, Massachusetts. , Boston, Mass.
Reprints: Liron Pantanowitz, MD, Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, 330 Brookline Ave, Boston, MA 02215.