Recurrent pyelonephritis due to NDM-1 metallo-beta-lactamase producing Pseudomonas aeruginosa in a patient returning from Serbia , France , 2012

C Flateau (claraflateau@yahoo.fr)1, F Janvier2, H Delacour2, S Males3, C Ficko1, D Andriamanantena1, K Jeannot4, A Mérens2, C Rapp1 1. Service des maladies infectieuses et tropicales, Hôpital d’instruction des armées Bégin, Saint-Mandé, France 2. Service de microbiologie-hygiène, Hôpital d’instruction des armées Bégin, Saint-Mandé, France 3. Service de médecine et maladies infectieuses, Hôpital Henri Duffaut, Avignon, France 4. Centre National de la Résistance aux Antibiotiques, Laboratoire de Bactériologie, Hôpital Jean Minjoz, Besançon, France

We describe the first isolation in France of a New-Delhi metallo-beta-lactamase-1 (NDM-1) producing Pseudomonas aeruginosa.In March 2012, a patient with history of prior hospitalisation in Serbia was diagnosed in France with acute pyelonephritis due to NDM-1 producing P. aeruginosa.Clinical and microbiological cure was obtained under appropriate antibiotic treatment.Two months later, she presented with a recurrence due to the same bacteria, with a favourable evolution.During both hospitalisations, contact isolation precautions were implemented and no crosstransmission was observed.
In March 2012, a patient with a history of prior hospitalisation in Serbia was diagnosed in France with acute pyelonephritis due to New Delhi metallo-beta-lactamase-1 (NDM-1) producing Pseudomonas aeruginosa.

Case report
In February 2012, a woman in her early 60s was referred to the Infectious Diseases Department of the Military Hospital Bégin (Saint-Mandé, France) for an acute pyelonephritis.She reported having undergone a surgical intervention in Serbia in November 2011.She stayed one month in hospital, with urinary catheterisation of undetermined duration but less than one month.The medical records reported a first treatment with cefuroxime and streptomycin just after surgery, and a history of fever, drowsiness and inflammatory syndrome two weeks after surgery, treated with ceftriaxone and streptomycine.Laboratory data were unavailable.
The urinalysis recovered 29,106 leukocytes/mL and 10 6 CFU/ml P. aeruginosa serotype 011 (HIABP11).The rectal swab, performed for multidrug resistant bacteria screening according to the French recommendations for patients with a history of hospitalisation abroad in the previous year [1], was also positive for P. aeruginosa.Blood cultures remained negative.Kidney ultrasonography was normal, kidney CT-scan showed a left pyelonephritis without abscess or urinary obstruction.The patient underwent urinary catheterisation and three weeks antibiotic treatment with aztreonam (2g TID) and colistin (2 million units TID).

Antimicrobial sensitivity testing and molecular diagnostics
For the isolates from urine and rectal swabs, antimicrobial drug susceptibility testing was performed by the disk diffusion method on Mueller-Hinton agar (I2A Laboratories, Perols, France) and interpreted according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) recommendations [2].It demonstrated resistance to imipenem, meropenem, doripenem, to all antipseudomonal cephalosporins, aminoglycosides, fluoroquinolones, rifampicine and tigecycline.Both isolates remained susceptible to piperacillin-tazobactam and intermediate to aztreonam (Table 1).Minimal inhibitory concentrations (MICs) of selected antimicrobials determined by microdilution and Etest (Biomérieux, Marcy l'Etoile, France) confirmed the results and showed susceptibility to colistin.The metallo-betalactamase-production screening in the meropenem-dipicolinic acid combined disk test (Klebsiella pneumoniae carbapenemas (KPC) + metallo-beta-lactamase (MBL) Confirm ID Pack, Rosco Diagnostica, Taastrup, Denmark) and in E-test with imipenem alone or combined with EDTA (Biomérieux, Marcy l'Etoile, France) was positive.

Monitoring of plasmatic and urinary concentrations of antibiotics
Aztreonam plasmatic peak and residual concentrations were 40 times and 4 times the MIC respectively for a dosage of 2g TID, while urine concentration was 166 times the MIC.Colistin plasmatic residual concentration (12 hours after injection) was under the MIC (0.7 mg/L, while the expected residual concentration is 2 mg/L, eight hours after injection); urine concentration was 10 times the MIC (Table 2).
Fever and abdominal pain resolved within 48 hours after administration of antibiotics while urinary incontinence persisted, requiring prolonged urinary catheterisation.Urinalysis 72 hours after the beginning of antibiotic treatment was normal and did not show any bacteria growth.The patient was discharged from hospital 21 days after admission.
During the stay at our hospital, a squamous-cell carcinoma of the oropharynx had been discovered and the patient underwent a first chemotherapy course at the beginning of May and was discharged from our hospital.One week later, she experienced dysuria and abdominal pain, without fever or flank pain.She was treated with ofloxacin (10 days) and prednisolone (seven days) by her GP.The urinalysis showed 42x10 4 leukocytes/mL (significant leukocytes count >10 4 /mL) and P. aeruginosa 10 3 CFU/mL.P. aeruginosa with the same antibiotic susceptibility pattern as previously was isolated and PCR for bla NDM-1 was again positive.Kidney ultrasound was normal.
The patient received piperacillin-tazobactam (4g TID) for three weeks, and her second chemotherapy course, without complication.The urinalysis after 72 hours of treatment was negative and the patient was discharged for at-home hospitalisation.
During both hospitalisations, contact isolation precautions with dedicated healthcare personnel were implemented.All patients hospitalised in the same ward were screened weekly with a total of 111 rectal swabs performed in 52 patients and no transmission of NDM-1 producing P. aeruginosa occurred.

Discussion and conclusion
Since the first description in 2008, of an NDM-1 carbapenemase in single isolates of Klebsiella pneumoniae and Escherichia coli [3], NDM-1-producing Enterobacteriaceae have been reported worldwide, mostly in patients with an epidemiological link to India or Pakistan [4,5].However, among 77 patients infected or colonised by NDM-1 producing Enterobacteriaceae reported in Europe from 2008 to 2010, five had been hospitalised previously in the Balkan region [6].Clinical isolates of NDM-1-producing A. baumanii are also increasingly reported in Europe [7] and importation of NDM-1 -producing A. baumannii from Serbia has been reported in 2011 [8].
We report here the first case of infection due to NDM-1-producing P. aeruginosa in France.To [11,12].
Secondly, NDM-1 producers have a potential for spread through the transfer of the plasmid-borne bla NDM1 gene [5].In P. aeruginosa, there is no complete documentation for plasmid-borne or chromosomal localisation for bla NDM1 gene yet.However, many outbreaks including carbapenemase-producing P. aeruginosa and spread of MDR P. aeruginosa clones have been recently reported, underlining that cross-transmission plays a major role in the spread of MDR P. aeruginosa in hospital settings [13,14].These considerations combined with the emerging character of our isolate in France are reason why all members of the medical and paramedical staff agreed to set up a dedicated team to care for the patient and a weekly screening of all contemporary patients on the same ward.
This strategy is recommended in France for carbapenemase-producing Enterobacteriae [1] without any mention of carbapenemase-producing Acinetobacter or Pseudomonas.However, in this particular case of a first isolation of NDM-1 producing P. aeruginosa in France, this strategy allowed us to assess the absence of cross-transmission for this isolate.
This observation highlights the emergence of NDM-1 not only in Enterobacteriaceae, but also in P. aeruginosa in Balkan area and France.In our view, NDM screening should be performed when a carbapenemase-producing Pseudomonadaceae clinical isolate is identified.

Table 1
date, Antibiotic susceptibility of Pseudomonas aeruginosa serotype 011 (HIABP11) strain isolated in a patient with history of previous hospitalisation in Serbia, France 2012 I: intermediate; R: resistant; S: susceptible.NA: not available.

Table 2
tam).Due to the low MIC recommended for the inferior breakpoint for aztreonam by EUCAST, wild type P. aeruginosa are reported as 'intermediate'.However MBLcarbapenemases do not hydrolyse the monobactam aztreonam and high dose therapy can be useful for patients infected with MBL-producing P. aeruginosa