Septic shock caused by Gardnerella vaginalis and Atopobium vaginae

Abstract

Although bacterial vaginosis is the most common and benign vaginal infection worldwide, some cases of severe acute infections have been described in the literature. We report the case of a 57-year-old French female who developed a life-threatening postoperative peritonitis after a total hysterectomy with adnexectomy in the context of the removal of leiomyosarcoma. The microbiological analysis of the peritoneal fluid identified Gardnerella vaginalis and Atobopium vaginae. The final diagnosis was a septic shock induced by an early onset peritonitis caused by Gardnerella vaginalis and Atobopium vaginae. The normal flora of the genital area could lead to a serious life threatening postoperative infection and should always be in the differential diagnosis.

Introduction

Bacterial vaginosis (BV) is the most common and benign vaginal infection worldwide [1]. It is a dysbiosis, resulting in an imbalance in the vaginal flora through the multiplication of anaerobic bacteria and the disappearance of well-known protective lactobacilli. Gardnerella vaginalis and Atopobium vaginae are especially known to be associated with BV [2,3]. Although BV is a benign pathology, we report a septic shock caused by Gardnerella vaginalis and Atopobium vaginae after a total hysterectomy with adnexectomy due to leiomyosarcoma.

Case report

A 57-year-old French menopausal female was admitted to the gynecological emergency unit with a 6-weeks history of left lower quadrant abdominal pain with pelvic heaviness and urinary frequency. She had a past history of 5 miscarriages and a tubal ligation. She was an active smoker and was no medication. On physical examination, a large and painful mass extending up to the umbilicus was palpated. Pelvic MRI showed a mass measuring 18 × 17 × 12 cm, well-delimited, polylobed, poorly vascularized, with central fluid component, seemingly located on the left ovary, extending up to the umbilicus. There was no lymphadenopathy, ascites or peritoneal implants. Uterus and adnexa were normal. Serum tumor markers were negative.

One month later, the surgical pelvic exploration revealed a 30-centimeter mass of the left broad ligament. There was no ascites or peritoneal carcinomatosis. Uterus and right adnexa were normal. A total hysterectomy with adnexectomy and removal of the mass was performed through median infra-umbilical laparotomy. The definitive histological diagnosis was leiomyosarcoma. On day 2 after surgery, the patient presented an isolated fever of 39 °C. Laboratory evaluation yielded a major inflammatory syndrome (leukocytes 15,000/μL, C-reactive protein 317 mg/dL). A contrast-enhanced computed tomography scan of the abdomen and pelvis showed a bilobed air and fluid collection suggesting an abscess, located in the retroperitoneum and extending along the left psoas muscle (9,1 × 7,4 × 7,5 cm) for one part and in the Douglas pouch (7,1 × 5,1 cm) for the other part. The patient’s blood pressure dropped suddenly (74/46 mmHg) and did not respond to intravenous volume replacement with 2 L of Ringer Lactate. A vasopressor therapy (continuous infusion of noradrenaline) was started, allowing blood pressure stabilization at 100/60 mmHg. The patient was then transferred to the operating room for an emergency revision surgery. The peritoneal cavity exploration revealed a moderately abundant non-purulent serosanginous peritoneal fluid and adhesions to the Douglas pouch, suggesting peritonitis. An attentive examination of the intra-abdominal organs revealed no surgical wound that might explain the infection. According to the French guidelines, an antibacterial treatment with piperacillin/tazobactam and gentamicin was administered, after microbiological samples were taken. The patient was extubated in the postoperative recovery room without any complication, but she still needed a hemodynamic support with noradrenaline.

She was transferred to the intensive care unit, where she slowly clinically improved. noradrenaline requirement decreased allowing its discontinuation on day 3 after revision surgery. This clinical improvement was associated with a decrease in inflammatory markers. On day 2, microbiological analysis of the peritoneal fluid identified Gardnerella vaginalis. gentamicin was discontinued, while metronidazole was added to the antibacterial treatment. On day 4, Atopobium vaginae was identified in the peritoneal fluid. Preoperative blood cultures remained sterile. Antibacterial susceptibility testing of Garderella vaginalis demonstrated resistance to metronidazole and ciprofloxacin but susceptibility to penicillin G, amoxicillin/clavulanate, cefotaxim, clindamicin and vancomycin. Antibacterial susceptibility testing of Atopobium vaginae showed susceptibility to all tested antibacterials, including metronidazole. In our patient’s case, piperacillin/tazobactam was active against both bacteria.

The final diagnosis was an early postoperative peritonitis-induced septic shock caused by Gardnerella vaginalis and Atobopium vaginae. The patient was discharged from the intensive care unit on day 5 after the second surgery and the antibacterial therapy was stopped on day 7.

Discussion

According to the literature data, this is a rare septic shock related to a peritonitis caused by Gardnerella vaginalis and Atopobium vaginae after a total hysterectomy with adnexectomy. Gardnerella vaginalis and Atopobium vaginae use glycogen to synthesize biogenic amines that reduce the activity of lactobacilli, what causes alkalization of the vaginal cavity and facilitates their own development. These flora modifications can be aggravated by various factors, such as hormonal changes, sexually transmitted infections, intrauterine device replacement, antibacterials, excessive intimate hygiene, stress or tobacco [4]. Regarding our patient, active smoking may have participated in the modification of her vaginal flora. Also, Gardnerella vaginalis and Atopobium vaginae can be commensals of vaginal flora, as well as of male urethral flora, after contact with women carrying these microbes [5]. Nonetheless, Gardnerella vaginalis is reported to be present in 90 % of women with bacterial vaginosis versus only 11.5–69% of disease-free women [6]. As well, Atopobium vaginae is reported to be present in 40–70% of women with BV versus less than 8% of disease-free women [7]. Our patient was not complaining of malodorous and greyish vaginal secretions, which are symptoms of BV and was likely an asymptomatic carrier. During this total hysterectomy, a vaginal incision in the abdominal cavity maybe caused a bacterial dissemination and quickly progressed to peritonitis and septic shock in this context of cancer.

The standard antibacterial treatment of BV is secnidazole or metronidazole [4]. Gardnerella vaginalis is known to be sensitive to metronidazole while Atopobium vaginae is known to be resistant to this antibacterial [2]. Persistent or recurrent BV is thus frequent after treatment with metronidazole. This may also be due to the production, by some strains of Gardnerella vaginalis or Atopobium vaginae, of a protective biofilm that limits the antibacterial effectiveness [8,9]. In our patient, we noted that the antimicrobial resistance pattern testing was unusual: Gardnerella vaginalis was resistant to metronidazole, while Atopobium vaginae was sensitive. Our patient had a severe infection implied to use a broad-spectrum antibacterial therapy: piperacillin/tazobactam.

The most similar case we found in the literature is a post-caesarean septic shock caused by Gardnerella vaginalis and Peptostreptococcus [10]. We also found various cases of acute gynecological and non-gynecological infections to one of the two organisms among men and women. Regarding Gardnerella vaginalis, we identified a case of bacteremia after vaginal myomectomy [11], vertebral osteomyelitis [12] and prostatic adenoma [13]. Regarding Atopobium vaginae, we identified a case of tubo-ovarian abscess after trans-vaginal oocyte retrieval [14] and endocarditis of the tricuspid valve [15]. Risk factors of immunodepression were identified in only two publications, which were type 1 diabetes [15] and chronic alcoholism [13].

The normal flora of the genital area could lead to a serious life threatening post-operative infection and should always be in the differential diagnosis.

Author agreement statement

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Ethical approval

This study did not need approval of an ethics committee.

Funding source

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Declaration of Competing Interest

Authors are no conflicts of interest to declare.