Three Cases of Post-Cataract Surgery Endophthalmitis Due to Rhizobium (Agrobacterium) radiobacter

Abstract

We present three unrelated post-cataract surgery endophthalmitis cases caused by Rhizobium radiobacter, hospitalized in three different hospitals. Early diagnosis was obtained in two cases by bacterial DNA detection in vitreous samples. All patients recovered from infection, but pars plana vitrectomy was needed in two patients due to rapid clinical deterioration. CASE REPORTSP atient 1. An 81-year-old female patient complained of decreased visual acuity (20/63) 4 weeks after cataract surgery (phacoemulsification) of the right eye (Table 1). Acute postoperative endophthalmitis with severe ocular inflammation was diagnosed. Vitreous (200-l) and aqueous humor (AH; 150-to 200-l) samples were tested by culture using brain heart infusion broth (AES Laboratories, Combourg, France) and eubacterial PCR, as previously described (5). Rhizobium radiobacter was detected by culture in AH and vitreous and by eubacterial PCR in the vitreous. Species identification was confirmed by PCR amplification and sequencing of the 16S rRNA gene (GenBank accession number JQ304788) from the vitreous sample and from isolated colonies, whereas phenotypic identification of the isolated strain remained ambiguous. A 440-bp DNA fragment of the 16S rRNA gene was amplified with primers 91E and 13BS as described by Gauduchon et al. (10). The amplicon was sequenced, and the sequence obtained was compared in a phylogenetic analysis with those available in the BIBI database (http://umr5558-sud-str1 .univ-lyon1.fr/lebibi/lebibi.cgi). Using an agar disk diffusion method (7), the strain was found to be intermediately susceptible to broad-spectrum cephalosporins (especially ceftazidime) but susceptible to cefepime, imipenem, and fluoroquinolones according to the interpretative criteria of the CLSI for Pseudomonas aeruginosa, as previously suggested (14). The patient received two intravitreal injections of vancomycin (1 mg) and ceftazidime (2 mg) on the day of admission and 4 days later, systemic antibiotics for 7 days (intravenous imipenem at 500 mg three times a day and ciprofloxacin at 500 mg orally twice a day), subconjunctival injections of dexamethasone, and topical steroid therapy. One year later, the outcome was favorable.Patient 2. A 75-year-old male patient presented with acute endophthalmitis of moderate severity (Table 1; Fig. 1), 9 days after an uncomplicated phacoemulsification. He was followed up for obstructive sleep apnea and hypertension. Vitreous and AH were sampled, and the patient received an intravitreal injection of vancomycin plus ceftazidime, a systemic antibiotic therapy (intravenous piperacillin at 4 g three times a day and levofloxacin orally at 500 mg once a day, for 7 days), and topical steroid therapy. The following day, visual acuity was reduced to light perception, a 1-mm hypopyon appeared, and a pupillary membrane prevented fundus examination. Pars plana vitrectomy (PPV) was performed on day 3 of hospitalization, and intravitreal injections of antibiotics were repeated the same day and 2 days later. R. radiobacter was detec...

Secondary Peritonitis Due toRhizobium radiobacter

“…This finding is consistent with previous studies that R. radiobacter is always susceptible to fluoroquinolones, fourth-generation cephalosporin, and carbapenems [15]. However, clinicians cannot ignore the potential of R. radiobacter acquiring resistance to thirdgeneration cephalosporins [4].…”

“…In addition, some indwelling devices, such as central venous catheters, peritoneal dialysis catheters, intraocular devices, and prosthetic cardiac valves, are other precipitating factors contributing to R. radiobacter infections [2,8,12,15]. By contrast to previous studies [2,8,[12][13][14][15], our patient is not an immunocompromised adult, nor did he have any intra-peritoneal device. Although the clinical scenario such as the present case is an extremely rare occurrence, we would suggest that R. radiobacter can cause infections, in both immunocompromised and immunocompetent patients, with or without an indwelling device.…”

Utility of broad-range 16S rRNA PCR assay versus conventional methods for laboratory diagnosis of bacterial endophthalmitis in a tertiary care hospital

“…R. radiobacter was formerly known as Agrobacterium radiobacter , identified as a cause of chronic endophthalmitis subsequent to cataract surgery 2523 in 2015, whereas there are several reports from Pennsylvania, USA25 and France 25…”

Rhizobium radiobacter Endophthalmitis following Intravitreal Ranibizumab Injection

“…However, its source in our patient is unclear, as it is an organism predominantly found in soil. A few cases have been reported in which it has caused both acute and chronic endophthalmitis following cataract surgery [3], and it was hypothesised in these cases that infection occurred as a result of conjunctival inoculation following patient contact with soil, but our patient reported no gardening activities following her intravitreal injection, suggesting that the organism was already present in the conjunctival sac.…”