Sphingomonas paucimobilis complicating vaginal fluid cultivation. A rare case

Sphingomonas paucimobilis represents an aerobic Gram-negative bacillus that is gaining recognition as an important human pathogen. These species are widely distributed in both natural environment and hospitals. They appear as opportunistic pathogen that take advantage of underlying conditions and diseases. Regardless of the clinical significance, pathogenic mechanism varies throughout current bibliography. Aim of our study, reflects presentation of a rare case of an out-patient clinical asymptomatic, with vaginal culture positive for this rare microorganism, S. paucimobilis. Assiduous diagnosis and therapeutic mapping consist necessary conditions of effective treatment.


Introduction
Sphingomonas paucimobilis depicts a glucose-no fermenting, strictly aerobic, Gram-negative bacillus that thrives in the natural environment, especially in water and soil.
At the same time, it has also been isolated from hospital settings, including hospital water systems, distilled water, dialysis fluid, nebulizers, and other respiratory therapy equipment. [1][2][3][4] S. paucimobilis has the property of being found in low carbon environment (oligotropic). It is used for bioremediation of the environment for its ability to decompose aromatic compounds. [5] Additionally, is characterized by catalase and oxidase activity, yellow pigment production, and slow motility with single polar flagellum. [6] S. paucimobilis was initially reported to cause human infection in 1979. It consists an opportunistic pathogen, isolated from blood, sputum, urine, wound, bile, cerebrospinal fluid, vagina, and cervix.
Its virulence is thought to be low, and identification of the organism from clinical specimen is rare.
However, it is associated with great variety of infections, concerning community-acquired and health care-associated ones.
Pap smear revealed no signs of malignancy. Abdominal MRI depiction confirmed fluid presence inside uterine cavity along with intense heterogeneity of uterine configuration.
Patient underwent hysteroscopic evaluation of uterine cavity along with diagnostic curettage.
During cervical penetration, a massive amount of yellow-pigmented fluid was noticed.
A cotton swab filled with suspected fluid sent for microbiologic evaluation and cultivation.
The sample from pus was cultured at 35 0 C for 24-hours and yielded yellow-pigmented, smoothed, convex, non-haemolytic, oxidase-and Gram stain showed gram-negative bacilli ( Figure II), which were identified as Sphingomonas paucimobilis by the VITEK® 2 Compact15 automated system (Biomereux, France).  Antibiotic susceptibility testing was performed both by the VITEK ® 2 Compact15 automated system and the ETEST ® method (Biomereux, France) on Mueller Hinton agar plates using an inoculum of 0.5 McFarland and a 24-hour incubation at 35 0 C.
Hysteroscopic evaluation of uterine cavity did not reveal signs of uterine malignancy.
Histologic examination of diagnostic curettage consisted areas of cervical and endometrial infection.
Patient discharged from hospital the folowwing day in good clinical condition. She reveived tb Amoxicillin and clavounic acid (Augmentin) for 10 days, 2 times per day.
Follow up with new vaginal fluid cultivation did not reveal presence of S. paucimobilis

Discussion
S.paucimobilis consists an aerobic, non-fermentative gram negative bacterium, widely distributed in the natural environment (e.g. water, soil).
It represents an opportunistic pathogen, considered to originate from contaminated hospital equipment or manipulation of some medical devices, causing hospital infections in immune-compromised patients and very rare in healthy persons.

Disclosure of interest
All authors declare any financial interest with respect to this manuscript.

Conclusion
S. paucimobilis represnts a Gram negative bacillus, relative rare isolated in gynecologic speciments. Assiduous therapeutic mapping consists ultimate scope, in order to avoid systemic infections and increase of patient's quality of life.