Extragenital Mycoplasma hominis infections in adults

Isolation of Mycoplasma hominis using the BACTEC 9000 series blood culture system

Mycoplasma hominis has been implicated as an important cause of septicaemia. There have been reported variances in the ability of blood culture systems to support the growth of this organism. In this study the ability of the BACTEC 9000 series automated system to grow and detect M hominis was assessed. Three of five wild M hominis strains grew in the BACTEC Anaerobic Plus/F medium but growth was not flagged by the detection mechanism of the system. It is recommended that users of the BACTEC 9000 series should use a seven day protocol and perform terminal subculture for suspected cases of M hominis septicaemia.

Sternotomy infection due to Mycoplasma hominis and Ureaplasma urealyticum

Mycoplasma hominis infections outside the urogenital tract are uncommon. An unusual case of sternal infection caused by both Mycoplasma hominis and Ureaplasma urealyticum is described. This is the first report found in the literature of mixed infection due to these microorganisms at this site. The outcome was favourable after drainage of the surgical wound and antibiotic therapy with clindamycin, gentamicin and doxycycline.

Mycoplasma hominis pneumonia in aboriginal adults

Mycoplasma hominis (M. hominis) is a well recognized extragenital pathogen. Its role as a pathogen of the respiratory tract, however, remains difficult to determine. Four cases of pneumonia are presented in which M. hominis was isolated from blood, tracheal aspirates or post-mortem lung tissue. All 4 of these isolates were in young Aboriginal adult males. M. hominis is the least fastidious of the human mycoplasmas and grows well on most blood-containing bacteriological media. The recognition and identification of M. hominis is important as it is commonly resistant to erythromycin which would be the drug of choice in most atypical pneumonias. Early recognition and treatment with tetracycline instead may influence outcome.

Acute pyelonephritis caused by Mycoplasma hominis

A 59-yr-old male alcoholic with bilateral nephrocalcinosis and upper urinary tract stones presented with fever, acute abdominal signs and ascites. Laparotomy revealed the presence of 1.5 litres of ascitic fluid and confirmed right-sided acute pyelonephritis. Culture of urine from the renal pelvis obtained during surgery was positive for Mycoplasma hominis. Initial therapy with cefuroxime failed and doxycycline was later initiated when culture was positive for Mycoplasma hominis, with definite clinical improvement. This is an unusual case of acute pyelonephritis with peritoneal signs and ascites due to Mycoplasma hominis in an elderly male who had no recent history of urinary tract instrumentation.

Diffuse alveolar hemorrhage associated with Mycoplasma hominis respiratory tract infection in a bone marrow transplant recipient

An 18-year-old woman developed respiratory distress and diffuse pulmonary infiltrates after allogeneic bone marrow transplantation. Bronchoalveolar lavage findings indicated diffuse alveolar hemorrhage. Cultures of the lavage fluid and the pharynx grew Mycoplasma species; the pharyngeal isolate was identified as Mycoplasma hominis. Mycoplasma hominis infection may have an etiologic role in diffuse alveolar hemorrhage.

Mycoplasma and Chlamydia in adenoids and tonsils of children undergoing adenoidectomy or tonsillectomy

The prevalence of mycoplasmal and chlamydial infection was assessed in 83 children undergoing adenoidectomy, tonsillectomy, or both procedures for recurrent adenotonsillitis or obstructive symptoms. Throat smears (surface specimens) and minced adenoids and tonsils (core specimens) were cultured for Mycoplasma spp and for Chlamydia spp. Isolation rates in adenoidal specimens were as follows: Mycoplasma hominis, surface 7.1% core 2.9%; and Ureaplasma urealyticum, surface 1.4%, core 2.9%. Mycoplasma hominis was also found in tonsillar specimens: surface 14.3%, core 20%. Chlamydia trachomatis was isolated only from a single core adenoidal specimen. The rate of mycoplasma isolation was significantly higher in children with recurrent adenotonsillitis (34.5%) than in those with obstructive symptoms (3.7%). Our findings document colonization of genital mycoplasmas in adenoids and tonsils of children with recurrent adenotonsillitis. Further studies are needed to evaluate the possible pathogenetic role of these microorganisms in adenotonsillar infection.

Posthysterectomy wound infection. A review

We reviewed the microorganisms isolated from gynecologic surgery wounds showing signs of infection, from January to December 1990. A total of 88 samples of abdominal wall exudates from as many patients who had undergone abdominal hysterectomy were studied. In 54 women (61.3%), cultures were positive and, in 26 specimens (48.1%), mixed aerobic-anaerobic flora were isolated. In 28 cases (51.9%), a single microorganism was isolated, the most frequent being Staphylococcus aureus, followed by Mycoplasma hominis and Escherichia coli. Mycoplasma hominis was unexpectedly frequent, appearing in five women with wall abscess and fever.

Evaluation of intraspecies genetic variation within the 16S rRNA gene of Mycoplasma hominis and detection by polymerase chain reaction

Mycoplasma hominis is a heterogeneous species with DNA-DNA hybridization values ranging from 51 to 100%. We report here the sequencing of the 16S rRNA gene of a strain (183) that greatly differs from the type strain (PG21) of this species. Comparison of 16S rDNA sequences from these two strains showed limited differences, indicating that the two strains belong to the same rRNA species complex. Using these nucleotide sequence data, we established a rapid method for the detection of M. hominis by using polymerase chain reaction. This method was shown to be sensitive and specific when tested with reference strains and clinical isolates.

Lumbar pain caused by Mycoplasma infection

A 45-year-old woman was admitted to hospital following acute onset of lower back pain. Clinical and laboratory investigations established a lumbar paraspinal soft tissue infection with Mycoplasma hominis associated with severe spondylarthrosis at L5/S1. A relationship to a recently performed hysterectomy must be considered.

Current trends in bacterial respiratory pathogens

The relationship of virulence and antimicrobial susceptibility with morbidity due to bacterial respiratory pathogens is complex and evolving. Ultimately, decreasing the incidence of pneumonia due to bacterial pathogens will be dependent on successful preparation and distribution of effective vaccines. Until effective vaccines are widely available, control of a majority of respiratory infections will depend on promotion of rational therapeutic strategies. Though limited to a few specific serotypes and strains, changes in virulence of bacterial respiratory pathogens have been noted. Co-infections due to multiple respiratory pathogens may increase morbidity; however, the epidemiology of co-infections is not clear. Relationships between respiratory viruses and bacteria may exist that increase virulence of both agents, but information regarding these relationships awaits further investigation. Resistance of respiratory pathogens to the more commonly used antimicrobials, such as penicillin, erythromycin, chloramphenicol, and cotrimoxazole, is being documented globally with increasing frequency. The evolution of antimicrobic resistance, especially among strains of Streptococcus pneumoniae, the most common and deadly agent of lower respiratory tract infections, provides impetus to develop and promote effective pneumococcal vaccines and to search for new and effective antimicrobials.