Pyogenic thigh abscess caused by Streptococcus constellatus subsp. constellatus in a patient with exacerbation of bronchiectasis: a case report

Abstract

Streptococcus constellatus (S. constellatus) is a Gram-positive commensal bacterium that is commonly found in the oral, nasal, pharyngeal, gastrointestinal, and urogenital tracts. It can be further consisted by three subspecies: subsp, constellatus, subsp. pharynges, and subsp. viborgensis. As an opportunistic pathogen, S. constellatus can cause abscesses and bacteremia, so infection requires timely and accurate identification in clinical practice. There are a few case reports describing the range of infections caused by S. constellatus, which include intracardiac, thoracic, intracranial, and abdominal infections. Here we report the first case of thigh abscess caused by S. constellatus subsp. constellatus which was rarely insensitive to penicillin in a patient with exacerbation of bronchiectasis. The patient improved significantly after receiving antibiotic therapy with ceftriaxone and vancomycin, as well as percutaneous catheter drainage guided by color ultrasonography.The thigh abscess did not recur during follow-up. This case report demonstrates that although S. constellatus is a rare infectious pathogen, it is important to gain a better understanding of the range of possible infections to ensure timely diagnosis. Furthermore, although the prognosis of most patients with such infections is relatively good, the timely identify the resistant strains and administration of sensitive antibiotics along with abscess drainage may ensure effective treatment.

Descending necrotizing mediastinitis caused by Streptococcus constellatus: A case report and review of the literature

“…First, NGS is not absolute in detecting pathogenic bacteria and there is also a possibility of missing detection. [ 6 ] Second, if a positive result is found, a drug sensitivity test cannot be performed to clarify the drug susceptibility of the organism compared to traditional pathogenic tests such as blood and sputum cultures. Third, the NGS is relatively expensive.…”

“…We searched PubMed database for cases of S constellatus over the last decade and found that almost cases reported abscess formation ranging from the brain, orbit, lung, and mediastinum to the heart, ovaries, kidney, liver, spine, and thighs. [6][7][8][9][10][11] We complied 6 cases of DNM caused by S constellatus, and this was the second case of such severe, rapidly progressing septic shock (Table 1). [11][12][13][14][15][16] In another case, which was also very aggressive, a patient developed necrotizing fasciitis in the maxillofacial region, neck, and upper mediastinum after experiencing cold and fatigue, followed by rapid decompensation with resulting septic shock caused by S constellatus and Klebsiella oxytoca.…”

Septic shock from multiple intra-abdominal Streptococcus constellatus abscesses unamenable to percutaneous drainage

“…Systemic infections of Streptococcus constellatus originating from a source in the head and neck are not uncommon [5]. This group of bacteria can cause a wide variety of infections; the most severe being bacteremia and distant focal infections or abscesses involving the central nervous, pulmonary and hepatic systems as well as soft tissues [4,[7][8][9]. Our patient had multiple liver abscesses and although these are traditionally associated with Escherichia coli and Klebsiella pneumoniae, one case series in the USA found Streptococci to be the most common pathogen [10].…”