Mycoplasma hominis brain abscess following uterus curettage: a case report
© Al Masalma et al; licensee BioMed Central Ltd. 2011
Received: 15 December 2010
Accepted: 3 July 2011
Published: 3 July 2011
Mycoplasma hominis is mostly known for causing urogenital infections. However, it has rarely been described as an agent of brain abscess.
We describe a case of M. hominis brain abscess in a 41-year-old Caucasian woman following uterus curettage. The diagnosis was obtained by 16S rDNA amplification, cloning and sequencing from the abscess pus, and confirmed by a specifically designed real-time polymerase chain reaction assay.
Findings from our patient's case suggest that M. hominis should be considered as a potential agent of brain abscess, especially following uterine manipulation.
Brain abscess is a life-threatening condition resulting from the invasion of brain tissues by microorganisms. Current microbiological documentation, mostly based on direct examination and culture of pus specimens, may underestimate the role of fastidious microorganisms in brain abscess . Among these, Mycoplasma hominis has rarely been reported [2–7]. M. hominis is a fastidious and slow-growing bacterium, commensal of the genitourinary tract of healthy adults. It mostly causes urogenital infections but may also cause extra-genital infections [8, 9]. Infections caused by Mycoplasma sp. require specific antibiotic treatment. Lacking a cell wall and folic acid synthesis, they are resistant to antibiotics that target the cell wall or folic acid synthesis . In particular, they are naturally resistant to β-lactams, which in combination with metronidazole have been recommended as empirical treatment of bacterial brain abscesses . In contrast, M. hominis is sensitive to antibiotics that prevent the synthesis of proteins, including tetracyclines . In addition, this bacterium cannot be Gram stained and requires specific culture media. However, molecular methods were successfully used to detect M. hominis from human samples .
In 2006, a previously healthy, 41-year-old Caucasian pregnant woman was admitted to our hospital with vertigo, severe headache, and left hemiparesis. She had no relevant medical history except two previous normal pregnancies and deliveries. A computed tomography (CT) scan and MRI scan of the brain identified a right fronto-parietal hematoma. The hematoma was surgically drained. Then 10 days later, at 22 weeks of gestation, our patient underwent early spontaneous miscarriage that required uterus curettage, complicated by important metrorrhagia. At three days following the miscarriage, our patient developed obnubilation, and subsequently coma. New cerebral CT and MRI scans revealed a fronto-parietal brain abscess. The abscess was surgically removed, and purulent material was sent to our laboratory. A nosocomial infection being suspected, an intravenous empirical treatment associating vancomycin (2 g/day) and meropenem (6 g/day) was started. Gram staining of the abscess specimen showed numerous polymorphonuclear leukocytes but no microorganism. The specimen was then plated onto 5% sheep blood agar and chocolate agar (BioMérieux, Marcy L'Etoile, France) and incubated at 37°C under aerobic, anaerobic, and microaerophilic conditions for 10 days. Plates were examined daily but no growth was observed. For molecular detection, DNA was extracted from the pus sample using the MagNA Pure LC DNA isolation kit II and the MagNA Pure LC instrument as recommended by the manufacturer (Roche, Meylan, France). Amplification and sequencing of the 16S rDNA gene were performed using broad range primers as previously described . By comparison with sequences from GenBank, the sequence obtained from the polymerase chain reaction (PCR) product (1,475 bp) was 100% identical to that of M. hominis (GenBank accession number AF443616). As a consequence, the antibiotic treatment was changed to doxycycline, 200 mg/day for 12 weeks. Our patient recovered rapidly. On follow-up, she remained asymptomatic six months after the discontinuation of antibiotics. In order to determine whether the infection was monomicrobial or polymicrobial, the PCR amplicon was subsequently cloned into Escherichia coli using the pGEM-T Easy Vector System (Promega, Charbonnières, France). A total of 100 clones were analyzed by sequencing. Only 16S rDNA from M. hominis was detected in the 100 clones. The identification of M. hominis in our patient and the previously published cases motivated the development of a specific real time-PCR (RT-PCR) assay for this bacterium. 16S rDNA was selected as target. Using the Primer Express software (Applied Biosystems), specific primers and probes were designed as follows: MHMGB16Sd (5'-TGT TAT AAG GGA AGA ACA TTT GCA AT-3'), MHMGB16Sr (5'-GCC ATC GCT TTC TGA CAA GG-3') and MHMGB16S probe (FAM-AAA-TGA-TTG-CAG-ACT-GAC-MGB) respectively. RT-PCR was performed using a LightCycler (Roche). The PCR mix consisted of 4 μL of pus DNA, 10 μL of Quantitect Probe PCR Master Mix (Qiagen, Courtaboeuf, France), 20 pM of each primer (Eurogentec, Seraing, Belgium), 0.5 μL of Uracil DNA glycosylase (Invitrogen), 0.5 μL of 3.125 μM MHMGB probe (Applera), and 4 μL of water. DNA was amplified using the following cycling parameters: heating at 50°C for 2 minutes, and then at 95°C for 15 minutes, followed by 50 cycles of a two-stage temperature profile of 95°C for one second and 60°C for 45 seconds. The specificity of the primers and probes was tested using BLAST http://blast.ncbi.nlm.nih.gov/ and by tentatively amplifying DNA from 24 distinct Mycoplasma species. The system was found to be specific to M. hominis, as no amplification was obtained from any other mycoplasmal or human DNA. For our patient, positive amplification was obtained after 22 PCR cycles. Negative controls remained negative.
Epidemioclinical features of previously reported patients with Mycoplasma hominis brain abscess
Traumatic brain hematoma and urinary tract catheterization
Head trauma and urinary tract catheterization
Brain hematoma following normal vaginal delivery
Subdural hematoma following normal full term pregnancy and delivery
Subdural hematoma following cesarean delivery
Normal full term pregnancy and delivery
Cases of hematoma (other than brain) infected with Mycoplasma hominis
Abdominal hematoma following cesarean section
Abdominal hematoma following cesarean section
Culture and PCR
Wound and peri-nephric hematoma following renal transplantation
Peri-nephric hematoma following renal transplantation
Thigh hematoma following trauma of pelvis and genitourinary tract
Peri-hepatic hematoma following liver transplantation
Retroperitoneal hematoma following pelvis trauma
Subcutaneous hematoma and respiratory tract infection
In addition, as previously reported , bacterial culture and Gram staining results remained negative. M. hominis was only detected by PCR. In addition, in an effort to reduce the diagnostic delay, we developed a specific RT-PCR for M. hominis. This test provides a rapid alternative not only to culture but also to broad-range 16S rRNA PCR and sequencing detection, and may enable rapid antibiotic treatment adaptation.
Our data suggest that M. hominis should be suspected in patients developing brain abscess following genitourinary tract invasive procedures, notably uterine curettage. To facilitate the detection of this agent, we developed an accurate, sensitive, and specific RT-PCR assay for M. hominis that may enable the diagnosis to be obtained within one hour of DNA extraction.
Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.
- Al Masalma M, Armougom F, Scheld WM, Dufour H, Roche PH, Drancourt M, Raoult D: The expansion of the microbiological spectrum of brain abscesses with use of multiple 16S ribosomal DNA sequencing. Clin Infect Dis. 2009, 48: 1169-1178. 10.1086/597578.View ArticlePubMedGoogle Scholar
- Douglas MW, Fisher DA, Lum GD, Roy J: Mycoplasma hominis infection of a subdural haematoma in the peripartum period. Pathology. 2003, 35: 452-454. 10.1080/00313020310001602684.View ArticlePubMedGoogle Scholar
- Escamilla F, Fernandez MD, Espigares A, Arnal C, Ortega A, Garcia T: Subdural empyema due to Mycoplasma hominis following epidural anesthesia. Rev Neurol. 2000, 30: 326-328.PubMedGoogle Scholar
- Kupila L, Rantakokko-Jalava K, Jalava J, Peltonen R, Marttila RJ, Kotilainen E, Kotilainen P: Brain abscess caused by Mycoplasma hominis: a clinically recognizable entity?. Eur J Neurol. 2006, 13: 550-551. 10.1111/j.1468-1331.2006.01209.x.View ArticlePubMedGoogle Scholar
- Payan DG, Seigal N, Madoff S: Infection of a brain abscess of Mycoplasma hominis. J Clin Microbiol. 1981, 14: 571-573.PubMedPubMed CentralGoogle Scholar
- Rao RP, Ghanayem NS, Kaufman BA, Kehl KS, Gregg DC, Chusid MJ: Mycoplasma hominis and Ureaplasma species brain abscess in a neonate. Pediatr Infect Dis J. 2002, 21: 1083-1085. 10.1097/00006454-200211000-00026.View ArticlePubMedGoogle Scholar
- Zheng X, Olson DA, Tully JG, Watson HL, Cassell GH, Gustafson DR, Svien KA, Smith TF: Isolation of Mycoplasma hominis from a brain abscess. J Clin Microbiol. 1997, 35: 992-994.PubMedPubMed CentralGoogle Scholar
- McMahon DK, Dummer JS, Pasculle AW, Cassell G: Extragenital Mycoplasma hominis infections in adults. Am J Med. 1990, 89: 275-281. 10.1016/0002-9343(90)90338-E.View ArticlePubMedGoogle Scholar
- Taylor-Robinson D: Genital mycoplasma infections. Clin Lab Med. 1989, 9: 501-523.PubMedGoogle Scholar
- McCormack WM: Susceptibility of mycoplasmas to antimicrobial agents: clinical implications. Clin Infect Dis. 1993, 17: S200-S201. 10.1093/clinids/17.Supplement_1.S200.View ArticlePubMedGoogle Scholar
- Mathisen GE, Johnson JP: Brain abscess. Clin Infect Dis. 1997, 25: 763-779. 10.1086/515541.View ArticlePubMedGoogle Scholar
- Myhre EB, Mardh PA: Treatment of extragenital infections caused by Mycoplasma hominis. Sex Transm Dis. 1983, 10: 382-385.PubMedGoogle Scholar
- Krijnen MR, Hekker T, Algra J, Wuisman PI, Van Royen BJ: Mycoplasma hominis deep wound infection after neuromuscular scoliosis surgery: the use of real-time polymerase chain reaction (PCR). Eur Spine J. 2006, 15: 599-603. 10.1007/s00586-005-0055-y.View ArticlePubMedPubMed CentralGoogle Scholar
- Drancourt M, Berger P, Raoult D: Systematic 16S rRNA gene sequencing of atypical clinical isolates identified 27 new bacterial species associated with humans. J Clin Microbiol. 2004, 42: 2197-2202. 10.1128/JCM.42.5.2197-2202.2004.View ArticlePubMedPubMed CentralGoogle Scholar
- McCormack WM: Epidemiology of Mycoplasma hominis. Sex Transm Dis. 1983, 10: 261-262.View ArticlePubMedGoogle Scholar
- Simberkoff MS, Toharsky : Mycoplasmemia in adult male patients. JAMA. 1976, 236: 2522-2524. 10.1001/jama.236.22.2522.View ArticlePubMedGoogle Scholar
- Burke DS, Madoff S: Infection of a traumatic pelvic hematoma with Mycoplasma hominis. Sex Transm Dis. 1978, 5: 65-67. 10.1097/00007435-197804000-00007.View ArticlePubMedGoogle Scholar
- Kailath EJ, Hrdy DB: Hematoma infected with Mycoplasma hominis. Sex Transm Dis. 1988, 15: 114-115. 10.1097/00007435-198804000-00010.View ArticlePubMedGoogle Scholar
- Koshiba H, Koshiba A, Daimon Y, Noguchi T, Iwasaku K, Kitawaki J: Hematoma and abscess formation caused by Mycoplasma hominis following cesarean section. Int J Womens Health. 2011, 3: 15-18.View ArticlePubMedPubMed CentralGoogle Scholar
- Legg JM, Titus TT, Chambers I, Wilkinson R, Koerner RJ, Gould FK: Hematoma infection with Mycoplasma hominis following transplant nephrectomy. Clin Microbiol Infect. 2000, 6: 619-621. 10.1046/j.1469-0691.2000.00147.x.View ArticlePubMedGoogle Scholar
- Yamaguchi M, Kikuchi A, Ohkusu K, Akashi M, Sasahara J, Takakuwa K, Tanaka K: Abscess formation due to Mycoplasma hominis infection after cesarean section. J Obstet Gynaecol Res. 2009, 35: 593-596. 10.1111/j.1447-0756.2008.00993.x.View ArticlePubMedGoogle Scholar
- Orange GV, Jones M, Henderson IS: Wound and perinephric haematomata infection with Mycoplasma hominis in a renal transplant recipient. Nephrol Dial Transplant. 1993, 8: 1395-1396.PubMedGoogle Scholar
- Jacobs F, Van de Stadt J, Gelin M, Nonhoff C, Gay F, Adler M, Thys JP: Mycoplasma hominis infection of perihepatic hematomas in a liver transplant recipient. Surgery. 1992, 111: 98-100.PubMedGoogle Scholar
- Ridgway EJ, Allen KD: Mycoplasma hominis abscess secondary to respiratory tract infection. J Infect. 1994, 29: 207-210. 10.1016/S0163-4453(94)90818-4.View ArticlePubMedGoogle Scholar
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