Campylobacter rectus is a Gram-negative, anaerobic rod, first described in 1981 as Wolinella recta, subsequently re-classified to Campylobacter based on phylogenetic analysis in 1991.1 It is found in the oral cavity and gastrointestinal tract, and is mainly implicated in oral and periodontal infections. So far, there are only a handful of case reports in the literature describing extra-oral invasive C. rectus infections.2–6 Recently, we described a case of fatal C. rectus infection, due to subdural empyema and ruptured mycotic intracranial aneurysm.2 In this article, we report a case of Lemierre's syndrome associated with C. rectus bacteremia.
A 53-year-old Chinese woman, with good past health, was admitted because of left upper neck pain for 1 week. The relentless pain drove her to seek acupuncture treatment 3 days before admission. Soon afterward, she experienced high swinging fever with aggravation of the left neck pain. Before the symptom onset, she had not experienced sore throat or bone impaction on ingestion. She was running a temperature of 38.5 °C on admission. Her neck was stiff and swollen. Oxygen saturation was 99% on room air. The white cell count was 21.7 × 109/L (normal range 3.9–9.9 × 109/L), with 91% (normal range 45%–70%) neutrophil. Renal function was normal. Liver function test was deranged with bilirubin 72 μmol/L (normal range 4–23 μmol/L), alanine aminotransferase 129 U/L (normal range 8–58 U/L), aspartate aminotransferase 144 U/L (normal range 15–38 U/L), alkaline phosphatase 286 U/L (normal range 42–110 U/L), and gamma-glutamyl transferase 260 U/L (normal range 11–62 U/L). Blood culture was taken right after admission before empirical intravenous vancomycin, ceftriaxone, and metronidazole were commenced. Computed tomography (CT) scan with contrast of the neck and thorax showed a multiloculated enhancing collection over the left neck at the level of C6/7 measuring 2.2 × 2.2 × 3.3 cm and another multiloculated lesion at C3-C6 level measuring 1.7 × 1.3 × 3.0 cm (Figure 1A). There was also filling defect in the proximal left internal jugular vein, measuring 0.4 × 0.5 × 1.7 cm (Figure 1B). Multiple rim enhancing collections were observed in both lungs (Figure 1C). A clinico-radiological diagnosis of Lemierre's syndrome was made. Emergency surgical drainage was performed and anticoagulation was started.
Blood culture was positive from the anaerobic bottle 3 days after incubation. The bacterium grew on blood agar as tiny non-hemolytic gray colonies after 7 days of incubation at 37 °C in anaerobic environment, but did not grow in ambient air or 5% CO2. Gram smear of the colonies showed small, pleomorphic Gram-negative rods, with some showing a curved appearance. The organisms were catalase-negative, oxidase-positive, and motile. They did not yield any recognizable biochemical profile when subjected to routine identification systems such as API 20A (BioMerieux, Marcy l’Etoile, France) and Vitek 2 ANC card (BioMerieux). Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry using direct colony method identified the isolate as C. rectus, but only with a score of 1.937. After using an extraction method with 70% formic acid and acetonitrile, the isolate was identified as C. rectus with a score of 2.256. 16S ribosomal ribonucleic acid (rRNA) sequencing using 16S-1F 5′-AGTTTGATCMTGGCTCAG-3′ and 16S-2R 5′-GGACTACHAGGGTATCTAAT-3′ (Sigma-Proligo, Hamburg, Germany) as primers and conditions we have described previously2 showed that the bacterium was C. rectus (Figure 2). The isolate is susceptible to penicillin and metronidazole by E-test according to the Clinical & Laboratory Standards Institute guideline, with minimal inhibitory concentrations of 0.032 μg/mL and 0.094 μg/mL, respectively.
The patient developed neutropenia on Day 17 and the antibiotics were switched to intravenous levofloxacin, clindamycin, and metronidazole. CT scan on Day 24 showed resolution of the thrombus with interval decrease in size of the abscess (Figure 1D). Anticoagulation was stopped. On Day 45, patient was discharged on oral levofloxacin, clindamycin, and metronidazole to complete three more weeks of treatment. CT scan at the end of oral antibiotics revealed complete resolution of the neck abscess (Figure 1E).
Lemierre's syndrome comprises of three elements: history of recent oropharyngeal infection, evidence of internal jugular vein thrombophlebitis, and evidence of metastatic infection in the lungs or other organs.7 Patients most commonly present with sore throat, followed by neck mass and neck pain. Up to 92% of patients have metastatic pleuropulmonary infection, including necrotic cavitatory lesions, infiltrates, empyema, and even necrotizing mediastinitis.8 Our patient was complicated by bilateral cavitatory lung lesions but involvements of other organs were not noted. The majority of Lemierre's syndrome is caused by Fusobacterium species, especially Fusobacterium necrophorum. Other implicated bacteria include Bacteroides species, Peptostreptococcus species, Prevotella species, Arcanobacterium haemolyticum, and oral Streptococcus species.7 In the present report that describes a case of Lemierre's syndrome associated with C. rectus, the most likely origin of the suppurative neck infection and septic thrombophlebitis, and hence the source of C. rectus, is still the oral cavity where the bacterium normally resides. Notably, no other bacteria of the oropharyngeal flora were isolated in the blood as co-pathogens, which were recovered in previous cases of invasive C. rectus infections.
In addition to the present case, there were only two other case reports describing intravascular infection by C. rectus. Leo et al. reported a case of left cavernous sinus thrombosis, complicated by pseudoaneurysm of internal carotid artery.3 Blood culture was positive and C. rectus was identified by 16S rRNA sequencing. The infection is likely coming from dental source with the left upper molar removed after dental assessment. The other one was reported by us describing a patient with left internal carotid artery mycotic aneurysm, subsequently ruptured and complicated by subdural empyema.1 Blood culture was positive for C. rectus and Porphyromonas gingivalis. Pus yielded from the subdural empyema grew Propionibacterium acne and C. rectus. The identity of C. rectus was also confirmed by 16S rRNA sequencing. No exact source was identified from this patient. Similar to the present case, both patients enjoyed good past health before admission.
Antibiotics and surgical intervention is the mainstay of treatment for invasive C. rectus infection. Given the scarcity of literature, there is no standardized antibiotics regimen available. Cases of C. rectus infection in the literature were treated with β-lactams (penicillin, ampicillin, ampicillin-sulbactam, piperacillin-tazobactam), clindamycin, and metronidazole with success.2–6 In particular, the only case of Lemierre's syndrome associated with C. rectus bacteremia was treated with amoxicillin-clavulanate.6 Although anticoagulation was started in our patient due to internal jugular venous thrombosis, the use of anticoagulation in Lemierre's syndrome is controversial. A recent retrospective case-control study investigated the benefit of giving anticoagulation in 18 patients diagnosed with Lemierre's syndrome.9 There was no demonstrable benefit in giving anticoagulation to achieve full resolution of thrombus. All patients had at least partial resolution of thrombus regardless of anticoagulation and no patients developed recurrent thrombosis in the follow-up period
We reported a case of Lemierre's syndrome associated with C. rectus bacteremia. The patient responded to antibiotics treatment, emergency surgical drainage, and anticoagulation with full recovery. 16S rRNA sequencing is the method of choice for accurately identifying C. rectus, with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry as an alternative but an extraction procedure has to be used for the best result.
. Vandamme P, Falsen E, Rossau R, et al. Revision of Campylobacter, Helicobacter
, and Wolinella
taxonomy: emendation of generic descriptions and proposal of Arcobacter
gen. nov. Int J Syst Bacteriol 1991;41(1):88–103.
. Lam JY, Wu AK, Ngai DC, et al. Three cases of severe invasive infections caused by Campylobacter rectus
and first report of fatal C. rectus
infection. J Clin Microbiol 2011;49(4):1687–1691.
. Leo QJ, Bolger DT Jr. Septic cavernous sinus thrombosis due to Campylobacter rectus
infection. BMJ Case Rep 2014;2014:bcr2013203351.
. Kakuta R, Hidaka H, Yano H, et al. First report of severe acute otitis media caused by Campylobacter rectus
and review of the literature. J Infect Chemother 2016;22(12):800–803.
. Ogata T, Urata T, Nemoto D, Hitomi S. Thoracic empyema caused by Campylobacter rectus
. J Infect Chemother 2017;23(3):185–188.
. Jawad II, Chandna A, Morris-Jones S, Logan S. Unusual case of Lemierre's syndrome
. BMJ Case Rep 2018;11(1):pii: e226948.
. Karkos PD, Asrani S, Karkos CD, et al. Lemierre's syndrome
: a systematic review. Laryngoscope 2009;119(8):1552–1559.
. Riordan T. Human infection with Fusobacterium necrophorum
(Necrobacillosis), with a focus on Lemierre's syndrome
. Clin Microbiol Rev 2007;20(4):622–659.
. Cupit-Link MC, Nageswara Rao A, Warad DM, Rodriguez V. Lemierre syndrome: a retrospective study of the role of anticoagulation and thrombosis outcomes. Acta Haematol 2017;137(2):59–65.