Granulicatella adiacens: An unusual causative organism for postoperative spinal infection

Murahari Penkunlinti; Rajkiran Reddy Banala; Vinayak K Santosh; Nagendra Vishnuvardhan Manyam; KS Vaisakhi; GPV Subbaiah

doi:10.4103/EJSS.EJSS_3_18

CASE REPORT

Year : 2018 | Volume : 2 | Issue : 1 | Page : 9-11

Granulicatella adiacens: An unusual causative organism for postoperative spinal infection

Murahari Penkunlinti¹, Rajkiran Reddy Banala², Vinayak K Santosh¹, Nagendra Vishnuvardhan Manyam¹, KS Vaisakhi³, GPV Subbaiah⁴
¹ Department of Spine Surgery, Star Hospitals, Hyderabad, Telangana, India
² SMART, Sunshine Hospitals, Secunderabad, Telangana, India
³ Department of Microbiology, Star Hospitals, Hyderabad, Telangana, India
⁴ Department of Spine Surgery; Department of Microbiology, Star Hospitals, Hyderabad, Telangana, India

Date of Web Publication

25-Sep-2018

Correspondence Address:
GPV Subbaiah
Department of Spine Surgery, Star Hospitals, Road No 10, Banjara Hills, Hyderabad - 500 034, Telangana
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/EJSS.EJSS_3_18

Abstract

Granulicatella species commonly known as nutritionally variant streptococci (NVS) are part of the normal oral flora and are found in the endocardium, dental plaques, dental abscesses, and endodontic infection. Severe complications may arise due to its ability to cause a variety of serious infections. The presence of Granulicatella species in spine or surgical site was never noticed or reported. Here, we present a rare case of G. adiacens in the muscular plane of L5–S1 vertebrae which were diagnosed radiologically and also microbiologically to give appropriate treatment to the patient for recovery.

Keywords: Granulicatella adiacens, nutritionally variant streptococci, postoperative surgical site infection and M

How to cite this article:
Penkunlinti M, Banala RR, Santosh VK, Manyam NV, Vaisakhi K S, Subbaiah G. Granulicatella adiacens: An unusual causative organism for postoperative spinal infection. J Spinal Stud Surg 2018;2:9-11

How to cite this URL:
Penkunlinti M, Banala RR, Santosh VK, Manyam NV, Vaisakhi K S, Subbaiah G. Granulicatella adiacens: An unusual causative organism for postoperative spinal infection. J Spinal Stud Surg [serial online] 2018 [cited 2023 Mar 29];2:9-11. Available from: https://www.jsss-journal.com/text.asp?2018/2/1/9/242154

Introduction

Post-operative surgical site infection (SSI) in spine surgery is a common complication, most commonly caused by Staphylococcus aureus.^[1] We encountered a rare case of postoperative SSI caused by Granulicatella adiacens, belonging to a species of nutritionally variant streptococci (NVS) which is a normal commensal of human mucosal surfaces inhabiting oral cavity, urogenital and gastrointestinal tracts, rarely causing diseases.

Case Report

Here, we report a rare case of postoperative SSI caused by G. adiacens in a 53-year-old female patient with known hypothyroidism, on treatment, and no other systemic diseases such as diabetes and hypertension. She was diagnosed with L5–S1 degenerative spondylolisthesis and was surgically treated with L5–S1 fusion via a posterior approach.

One month postsurgery, the patient presented with severe back pain with discharge from the surgical site and on clinical examination, there was a swelling (10 cm × 10 cm) with purulent discharging sinus at the surgical site. No sign of infection was noted on plain X-ray radiography, but magnetic resonance imaging showed the well-defined fluid collection in a subcutaneous and muscular plane in the lumbar spine which was hyperintense on the T2-weighted image 1 (WI) and hypointense on T1-WI [Figure 1].

Figure 1: Magnetic resonance imaging spine shows the infection in the muscular plane near to L5–S1 region (The red arrows indicate the site of surgery [arrow 1] and site of infection [arrow 2])

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Patient's complete blood profile showed hemoglobin level was 11 g/dL, white blood cell count was 11,800/μL, platelet count was 24.6 × 10⁴/μL, erythrocyte sedimentation rate was 92 mm/h, and C-reactive protein was 11.0 mg/dL. Pus samples were examined microbiologically as described below. Pus sample collected from the site of infection was inoculated on 5% sheep blood agar. Cultures were incubated at 37°C in CO₂ for 24 h. After incubation, the culture plates showed nonhemolytic, smooth colonies, and satellitism [Figure 2]a and [Figure 2]b. On gram-staining, the organism was found to be Gram-positive cocci. Antibiotic sensitivity test revealed susceptibility to aminoglycosides, fluoroquinolones, and beta-lactams antibiotics [Table 1]. The patient was treated with parenteral antibiotics for 2 weeks, followed by oral medication. Her clinical condition has then improved significantly.

Figure 2: Culture plates showing smooth colonies (2a) and satellitism (2b)

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Table 1: Indicates the sensitivity of Granulicatella adiacens towards various antibiotics

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Discussion

Postoperative SSI is a common complication observed in many patients, where S. aureus is implicated in most cases, but causative organisms such as G. adiacens is a rarity, especially in spinal infection. Granulicatella species are considered as a least common cause of infection.

G. adiacens is a very common bacterium existing in the normal flora of oral cavity, gastrointestinal tract, urogenitals, etc., of the general population, but few virulent and resistant species are also existing which could be of great concern. G. adiacens is a catalase-negative, Gram-positive cocci which usually grows in chain form and display satellites, but when cultured in less nutrient medium they tend to appear pleiomorphic.^{[1],[2],[3],[4],[5]} This bacterium is often difficult to identify because it will grow initially in blood culture broth or mixed cultures but not on sheep blood agar unless pyridoxal (Vitamin B₆) is added.^[4] Frenkel and Hirsch were the first to describe it nearly 50 years ago, as a new type of satilliting, Gram-positive cocci termed “NVS” due to the necessity for pyridoxal for its growth.^[6] The infection caused by G. adiacens is usually mistaken as infection caused by streptococcus^[7] causing misdiagnosis. With 16S rRNA sequencing, one can identify the causative agent within 4 h, instead of waiting for the culture reports, etc.^[8] Hence, the 16S rRNA sequencing must be used routinely to restrict the misdiagnoses in the future.^[7],[8]

In our case, the causative agent was found to be susceptible to most antibiotics and on the administration of amoxicillin and clavulanic acid, the patient showed significant signs of recovery.

Conclusion

G. adiacens is known to cause various infections such as endocarditis, osteomyelitis, arthritis, sepsis, etc., In summary, postoperative spinal infection due to NVS can be easily misdiagnosed when the blood-cultures are reported negative. NVS infection must be considered as a cause of infection if a patient with spinal infection shows positive Gram-staining and negative blood cultures.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Acknowledgment

We wish to thank our pathologists, radiologists, and colleagues for helping us with the case study.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

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