Bacteremia and urinary tract infection associated with CDC group Vd biovar 2

The Genus Ochrobactrum as Major Opportunistic Pathogens

Ochrobactrum species are non-enteric, Gram-negative organisms that are closely related to the genus Brucella. Since the designation of the genus in 1988, several distinct species have now been characterised and implicated as opportunistic pathogens in multiple outbreaks. Here, we examine the genus, its members, diagnostic tools used for identification, data from recent Ochrobactrum whole genome sequencing and the pathogenicity associated with reported Ochrobactrum infections. This review identified 128 instances of Ochrobactrum spp. infections that have been discussed in the literature. These findings indicate that infection review programs should consider investigation of possible Ochrobactrum spp. outbreaks if these bacteria are clinically isolated in more than one patient and that Ochrobactrum spp. are more important pathogens than previously thought.

Clinical characteristics of Ochrobactrum anthropi bacteremia

The clinical picture of Ochrobactrum anthropi infection is not well described because the infection is rare in humans and identification of the pathogen is difficult. We present a case of O. anthropi bacteremia that was initially misidentified as Ralstonia paucula and later identified by 16S rRNA sequencing and recA analysis.

Urinary tract infection due toAchromobacter xylosoxidans: Report of 9 cases

Urinary tract infection (UTI) due to Achromobacter xylosoxidans is rare. The aims were to know the frequency and clinical characteristics of this infection in our area. We performed a retrospective analysis of 9 patients with UTI caused by this organism diagnosed over a period of 13 y. The mean age was 63.1 y. All patients had underlying diseases or urological abnormalities. The most frequent underlying diseases were solid or hematological malignancies (3 cases). Seven patients (77.7%) had urological abnormalities. Eight patients had symptoms of cystitis and 1 remained asymptomatic. Seven patients had community acquired UTIs. Clinical outcome was favourable in 5 patients after antibiotic treatment and recurrence occurred in 3 patients who had urological abnormalities. All isolates were susceptible to imipenem and piperacillin-tazobactam, 88.8% were susceptible to ceftazidime and 77.7% were susceptible to trimethoprim-sulfamethoxazole. High frequencies of resistance to ampicillin (100%), amoxicillin/clavulanic acid (78%), cefuroxime (100%), cefotaxime (67%), norfloxacin (89%), ciprofloxacin (78%), nitrofurantoin (89%) and gentamicin (67%) were observed. UTI due to A. xylosoxidans was predominantly observed in elderly patients with predisposing factors, especially urological abnormalities, malignancies and immunosuppression. Treatment can be difficult due to the high level of antibiotic resistance. Trimethoprim-sulfamethoxazole may be useful for treatment, particularly in outpatients with community acquired infections.

Prosthetic mitral valve endocarditis due to Ochrobactrum anthropi: case report

We describe a case of infective endocarditis in a prosthetic mitral valve due to Ochrobactrum anthropi. Although O. anthropi is an emerging pathogen in immunocompromised patients, infections with the bacterium have very rarely been documented in healthy hosts, and endocarditis is rare. To our knowledge, only two cases of O. anthropi endocarditis have been reported in the medical literature.

Infective endocarditis and septic embolization with Ochrobactrum anthropi: case report and review of literature

Ochrobactrum anthropi, previously known as CDC group Vd, is an aerobic, Gram-negative bacillus of low virulence that occasionally causes human infection. We describe a case of infective endocarditis with O. anthropi complicated by septic embolization. A review of all the literature reported cases of O. anthropi infection is presented and categorized into 'Central line related', 'Transplant related' and "Other pyogenic infections". Mortality appears to be related to the underlying disease state, rather than the organism.

Pharmacokinetics of single daily dose gentamicin in children with cancer

PURPOSE

To study the pharmacokinetics of single daily dose (SDD) gentamicin in children with cancer.

METHODS

Serum concentrations of gentamicin were prospectively measured at 0.5, 8, 16, and 24 hours after a single daily dose of gentamicin 6 mg/kg, given as a 30-minute infusion in 18 febrile children with cancer and a central venous catheter. Then the peak (0.5-hour) and 12-hour serum concentrations of gentamicin were prospectively measured after a SDD of 7 mg/kg during 73 febrile episodes in 54 pediatric cancer patients with suspected infections. The aim was to achieve a peak serum concentration of 15 to 20 microg/mL 10 times the minimum inhibitory concentration (MIC) for sensitive Pseudomonas strains, resulting in good bactericidal activity and a long post-antibiotic effect (PAE) after a SDD of gentamicin.

RESULTS

The mean serum peak gentamicin concentration 30 minutes after the end of the infusion of 6 mg/kg was 13.3 +/- 4.0 microg/mL. The mean serum concentration 16 hours after the infusion was 0.3 +/- 0.2 microg/mL. The mean peak and 12-hour serum concentration after SDD of 7 mg/kg was 17.2 +/- 3.9 microg/mL and 0.9 +/- 0.7 microg/mL, respectively. The mean peak serum concentration after SDD of 7 mg/kg in children younger than 5 years of age (16.1 +/- 3.5 microg/mL ) was significantly lower than that of children over 5 years of age (18.2 +/- 3.9 microg/mL; P = 0.02). The desired peak serum concentration was achieved in 67% of children younger and 84% of those older than 5 years of age.

CONCLUSION

Adequate peak serum concentrations of gentamicin in children may be obtained with a SDD of 7 mg/kg. Children younger than 5 years of age achieve lower peak serum gentamicin concentration after SDD of 7 mg/kg than those older than 5 years.

Intravenous line infection due to Ochrobactrum anthropi (CDC Group Vd) in a normal host

Ochrobactrum anthropi, formerly known as Achromobacter species (CDC group Vd), is an aerobic, gram-negative bacillus widely distributed in aquatic environments. Most important, it has been implicated as a cause of intravenous line infection in immunocompromised hosts with solid tumors or hematologic malignancies. Trimethoprim-sulfamethoxazole and aminoglycosides are usually active against O. anthropi, but this organism is usually resistant to beta-lactam antibiotics. Because O. anthropi is a low-virulence organism, patients with intravenous-line infections have been cured without removal of the intravenous catheter. We describe a case of intravenous-line infection in a normal host that was successfully resolved alter catheter removal.

Ochrobactrum anthropi bacteremia: report of four cases and short review

Ochrobactrum anthropi, formerly "Achromobacter" CDC group Vd, is a nonfermentative, nonfastidious gram-negative bacillus, that only recently has been given attention as a potential human pathogen. Over a 2-year period, we observed four patients with multiple blood cultures that were positive for the organism. The patients had acute leukemia as underlying disease, and presented with clinical and microbiologic features consistent with catheter-related bacteremia. In three of the patients the infection initially appeared to be unrelated to chemotherapy-associated profound neutropenia and occurred early after, or was the reason for, hospital admission. The antimicrobial susceptibility of the isolates varied: unlike previously reported cases, resistance in some of our isolates included aminoglycosides, newer fluoroquinolones, and trimethoprim-sulfamethoxazole. Despite in vitro susceptibility to imipenem in initial isolates, treatment of two patients with this agent obviously failed to eradicate the organism, and the patients either relapsed with bacteremia shortly after discontinuation of treatment or remained persistently febrile and bacteremic. O. anthropi appears to be increasingly recognized as a human opportunist pathogen associated with intravascular catheters and unpredictable multiple antibiotic resistance.