Urinary tract infection caused by carbapenem-resistant K. pneumoniae and P. aeruginosa.

There has been an increase in recent years of antimicrobial resistance of Gram negative bacilli (GNB). Carbapenems, the mainstay for the treatment of multidrug resistant GNB infections, are no longer always effective leaving treatment options limited. We present the case of patient with recurrent, complicated urinary tract infections. The current episode was caused by carbapenem-resistant K. pneumoniae and P. aeruginosa and carbapenem-susceptible, but MDR E. cloacae. Resistance to carbapenems of K. pneumoniae was conferred by the production of the class B metallo-beta-lactamase, VIM1. Infection control measures were implemented and following a 2-week course of treatment with colistin, the infection resolved and the patient was discharged. We discuss the changes in the epidemiology, the mechanisms involved and the means of detecting carbapenem resistance in GNB. We would also like to stress the role of infection control measures in limiting patient-to-patient spread of MDR organisms which, are of paramount importance in cases when few treatment options are left available.

Multiple mobile promoter regions for the rare carbapenem resistance gene of Bacteroides fragilis.

Two novel insertion sequences (IS), IS1187 and IS1188, are described upstream from the carbapenem resistance gene cfiA in strains of Bacteroides fragilis. Mapping, with the RACE procedure, of transcription start sites of cfiA in these and two other previously reported IS showed that transcription of this rarely encountered gene is initiated close to a variety of B. fragilis consensus promoter sequences, as recently defined (D. P. Bayley, E. R. Rocha, and C. J. Smith, FEMS Microbiol. Lett. 193:149-154, 2000). In the cases of IS1186 and IS1188, these sequences overlap with putative Esigma(70) promoter sequences, while in IS942 and IS1187 such sequences can be observed either upstream or downstream of the B. fragilis promoters.

Antibiotic resistance in salmonellae isolated from humans and animals in France: comparative data from 1994 and 1997.

Among 25526 recorded isolates of salmonellae, 5086 isolated from humans and 20440 from animals in 1994 and 1997 in France, the antibiotic resistance phenotype was determined for all human and 5336 animal isolates. In Salmonella enterica serovar typhimurium, one of the two most frequently isolated serovars from humans as well as animals, resistance to ampicillin was observed in 61% of both human and animal isolates in 1994 and in 73% of human and 53% of animal isolates in 1997. During these periods, resistance to co-amoxiclav was between 45% and 66% for both types of isolate. Resistance to ampicillin was associated with resistance to streptomycin, spectinomycin, sulphonamide, tetracycline and chloramphenicol in over 70% of isolates. Resistance to ampicillin as well as co-amoxiclav never exceeded 7% in Salmonella enteritidis. While Salmonella hadar was practically absent among the human isolates in 1994, this serovar was the third most frequent in 1997, and at that time 92% were resistant to nalidixic acid. Among the animal S. hadar isolates, the prevalence of resistance to nalidixic acid increased from 3% in 1994 to 72% in 1997. None of these isolates manifested high-level resistance to ofloxacin. The levels of resistance to aminoglycosides (< or =3%) and trimethoprim-suphamethoxazole (< or =14%) remained practically unchanged in all three serovars. The resistance markers of 463 ampicillin-resistant S. typhimurium isolated in 1997 were determined. Among the 24 phenotypes observed, six multiresistance phenotypes, representing 82% of these isolates (as compared with 80% in 1994), were associated with the PSE-1 gene typically found in the lysotype DT104 of this serovar.

Multidrug-resistant human and animal Salmonella typhimurium isolates in France belong predominantly to a DT104 clone with the chromosome- and integron-encoded beta-lactamase PSE-1.

Epidemiologic relationships were investigated in 187 ampicillin-resistant Salmonella typhimurium strains (86 human, 101 animal) from >2000 strains isolated in 1994. Of 23 resistance patterns, the most frequent (ampicillin [Am], chloramphenicol [Cm], tetracycline [Tc], streptomycin and spectinomycin [Sm], and sulfonamides [Su]) was found in 69.5% of human and 64.8% of animal isolates. Four beta-lactamase genes were identified, blaTEM (24%), blaPSE-1 (78%), and blaSHV and oxa-2 (each <3%). blaPSE-1 and the integrase gene, intI1, but not blaTEM, blaSHV or oxa-2, were chromosomeborne and found almost exclusively in the AmCmTcSmSu strains. In these, polymerase chain reaction mapping revealed two distinct integrons carrying blaPSE-1 or aadA2. Lysotypes, plasmid profiles, and restriction fragment length polymorphisms (IS200) were determined for 50 representative isolates and for 3 DT104 strains from the United Kingdom (UK). The phage type of the PSE-1-producing AmCmTcSmSu strains was 12 atypic, indistinguishable from that of the DT104 strains. The combined data indicate that the same multiresistant clone has spread through human and animal ecosystems in the UK and France.

Surveillance of antibiotic resistance in Salmonella.

The World Health Organisation has recently pointed out an alarming increase in the incidence of antibiotic resistant strains of Salmonella, which are due to the use of antibiotics in intensive breeding. In France, until recent years, no or few cases of a

[Antibiotic susceptibility of 2 800 strains of Salmonellae and Shigellae isolated in France, 1994.]. / Sensibilité aux antibiotiques de 2 800 souches de salmonelles et shigelles isolées en France en 1994.

A retrospective study of the antibiotic susceptibility of Salmonellae and Shigellae isolated in France during 1994 was carried out by the Collège de Bactériologie, Virologie et Hygiène des Hôpitaux de France. The results of 2 800 susceptibility tests were provided by 76 centres representative of the french territory. This study reveals the frequency of high-level resistance among certain isolates, such as 1 093 strains of S. typhimurium to aminopenicillins, tetracyclines, chloramphenicol or cotrimoxazole, whereas others, like S. enteritidis (1 016 strains), showed practically no resistance. Some antibiotics can therefore no longer be used as first line therapy against bacteremia due to Salmonella.

[Resistance phenotypes and genotypes of 182 ampicillin-resistant Salmonella Typhymurium strains of human and animal origin.]. / Phénotypes et génotypes de résistance de 182 souches de Salmonella sérotype Typhimurium résistantes à l'ampicilline d'origine humaine et animale.

Among the Salmonellae, an increase in the frequency of antibiotic resistance is mainly observed for S. Typhimurium, one of the most common serotypes encountered in human and animal diseases. One hundred and eighty-two ampicillin-resistant strains of S. Typhimurium, including 82 of human and 100 of animal origin, have been compared. The frequency of tetracycline, sulfonamide, streptomycin and chloramphenicol resistance was high (> 84 %) in both groups, the most common resistance pattern including these four antibiotics. By dot-blotting and hybridization with DNA probes, the genes encoding three types of beta-lactamase were detected. The TEM-type was found in 20 % and 22 % of human and animal strains, the CARB-type in 73 % and 77 %, respectively. The TEM- and CARB-types were found associated in five strains (four from humans an one from animal), and the OXA-2-type in only one human strain. The presence of the CARB-type genes was strongly correlated with that of the integrase (TnpI), independently of the origin of the strains, while the integrase gene in animal strains was also found in ca. 50 % of the strains carrying only TEM-type genes. These results suggest the acquisition and concommittant diffusion, in S. Typhimurium of human and animal origin, of integrons carrying multiple resistance genes including blacarb.

A recent fixation of cfiA genes in a monophyletic cluster of Bacteroides fragilis is correlated with the presence of multiple insertion elements.

Small-subunit ribosomal DNA sequences of 16 strains of Bacteroides fragilis were determined and compared with previously published sequences. Three phylogenetic methods (the neighbor-joining, maximum-likelihood, and maximum-parsimony methods) as well as a bootstrap analysis were used to assess the robustness of each topology. All phylogenetic analyses demonstrated that the B. fragilis strains were clearly divided into two robust monophyletic units which corresponded to the cfiA-negative and cfiA-positive groups. Strains of two previously identified DNA homology groups separated similarly into the two monophyletic units. According to the intensity of the hybridization signal with a cfiA probe, the cfiA-positive cluster could be further divided into two groups. This difference might reflect the existence of two, probably closely related cfiA-type genes. In the strongly hybridizing cfiA-positive strains, the gene is capable of conferring high-level resistance to the carbapenems and to most beta-lactamase inhibitors as well, while in the weakly hybridizing cfiA-positive strains, only the latter type of resistance is known to occur. The presence of the cfiA-type genes within a monophyletic cluster of B. fragilis that apparently represents only a minority of the species B. fragilis is suggestive of a recent acquisition. The fact that this cluster is also the predominant pool of all known B. fragilis insertion elements, which have been found to play an important role in the expression of carbapenem resistance, raises the possibility that both genetic determinants, i.e., the resistance gene(s) and insertion elements, may have coevolved.

Genotypic identification of two groups within the species Bacteroides fragilis by ribotyping and by analysis of PCR-generated fragment patterns and insertion sequence content.

Molecular typing allowed the separation of the species Bacteroides fragilis into two genotypically distinct groups. A unique set of 50 strains of B. fragilis carrying the chromosomal metallo-beta-lactamase gene cfiA was subjected to a comparative analysis with respect to sets of up to 250 randomly collected strains devoid of this gene. The two groups were found to be distinct on the basis of the following results: (i) ribotyping, after DNA digestion with AvaI, revealed a practically homogeneous DNA fragment pattern for the cfiA-positive strains and distinct multiple patterns for the cfiA-negative strains; (ii) PCR, arbitrarily primed with an experimentally selected decamer, generated fragment patterns typical for the strains of each group; (iii) the three insertion sequences described to date in the species B. fragilis, i.e., IS4351, IS942, and IS1186, were all but confined to the cfiA-positive group, in which they were capable of providing promoter sequences for the transcription of cfiA; and (iv) the cepA gene, encoding the so-called endogenous cephalosporinase of B. fragilis, was found exclusively in the cfiA-negative group, in which it was present in ca. 70% of the strains. The cfiA-, cepA-negative fraction was not characterized further. In a natural population of 500 randomly selected strains of B. fragilis, the cfiA-positive and cfiA-negative groups represented ca. 3 and 97% of the strains, respectively. Analysis of 82 metabolic traits revealed no difference between the two groups.

Insertion of a novel DNA sequence, 1S1186, upstream of the silent carbapenemase gene cfiA, promotes expression of carbapenem resistance in clinical isolates of Bacteroides fragilis.

A small number of isolates of Bacteroides fragilis, an anaerobic pathogen of the human intestinal flora, carries a copy (or copies) of the carbapenemresistance gene, cfiA, which may be silent or expressed. We have studied the mechanism of activation of the frequently silent gene in in vitro-selected mutants and in clinical isolates. In both types of strains, activation was observed as the consequence of the insertion, at several possible sites, of a novel 1.3 kb insertion sequence, IS1186, immediately upstream of the carbapenemase gene. IS1186 has two open reading frames, on opposite strands, with coding capacities for a 41.2 kDa (ORF1) and a 22.5kDa (ORF2) protein. The 41.2kDa protein has homology with some proteins predicted from open reading frames of IS elements or DNA direct repeats of aerobic, but not anaerobic, Gram-negative bacteria. Upon insertion, transcription of cfiA was found to be driven from a promoter identified on the right end of IS1186. In one instance, insertion occurred into the putative ribosome-binding site of cfiA, leaving intact the tetranucleotide AGAA which is concluded to be a fully functional ribosome-binding site. Between 3 and 14 copies of IS1186 were detected per genome and the element was found, within the species B. fragilis, almost exclusively in the subgroup carrying the cifA gene.

Unusual neurologic manifestations occurring during dengue fever infection.

This is a report on dengue fever in two young patients in France that were infected in New Caledonia and Thailand. Both presented with unusual neurologic manifestations. The first patient developed a focal subarachnoid hemorrhage that was associated with transient thrombocytopenia. No neurologic vascular malformation was detected; a mild dengue hemorrhagic fever after a previous dengue infection was suspected. The second patient showed peripheral facial palsy one week after apyrexia without any other etiology except the dengue infection. This case was probably a postinfectious syndrome associated with dengue virus. Both patients recovered spontaneously. The circumstances of the neurologic manifestations in these patients may be attributed to the dengue fever virus. However, although neurologic complications reported for dengue fever are unusual, it is reasonable to consider these manifestations as being due to immunopathologic consequences.

Survey of the susceptibility patterns of Bacteroides fragilis group strains in France from 1977 to 1992.

Rates of antibiotic resistance within the Bacteroides fragilis group were monitored over a 15-year period in France by examining studies that employed the same methodology to test susceptibility of anaerobic bacteria. Chloramphenicol, metronidazole, beta-lactam/beta-lactamase inhibitor combinations and imipenem remained very active against Bacteroides fragilis. There was little or no change in rates of resistance to these antibiotics. Resistance to clindamycin increased from 1% in 1977 to a peak of 19% in 1987, and since then has remained at 8 to 12%. There was some evidence that resistance to most beta-lactam agents increased during the same period. These results emphasize the need for periodic surveys of resistance patterns of the Bacteroides fragilis group in each country.

Seven years of recurrent severe strongyloidiasis in an HTLV-I-infected man who developed adult T-cell leukaemia.

OBJECTIVE: Human T-cell leukaemia/lymphoma virus type I (HTLV-I) is endemic in Japan, the Caribbean basin and Africa, where it has been aetiologically linked to certain chronic myelopathies and adult T-cell leukamia (ATL). We sought to investigate whether strongyloidiasis, a parasitic disease common in these areas, might be a cofactor in the pathogenesis of ATL, as some reports have suggested. PATIENTS, PARTICIPANTS: One 35-year-old HTLV-I-seropositive French West Indian man with a 7-year history of recurrent strongyloidiasis associated with episodic hyperinfestation presenting at the Centre Hospitalier Intercommunal, Villeneuve St Georges, France. INTERVENTIONS: Treatment with various chemotherapeutic agents and symptomatic therapy for hypercalcaemia and antiviral therapy (zidovudine and interferon). RESULTS: The patient developed ATL and died shortly after, despite chemotherapy. Immunological and virological studies performed during the last 15 months of his life showed an increase of the percentage of peripheral ATL cells, and progression from a polyclonal to a monoclonal integration of HTLV-I proviral DNA in the peripheral blood mononuclear and lymph-node cells. CONCLUSIONS: Recurrent strongyloidiasis appears to have been a possible cofactor associated with progression from healthy carrier state to ATL in our patient.

A silent carbapenemase gene in strains of Bacteroides fragilis can be expressed after a one-step mutation.

High-level carbapenem-resistant (CpmR) mutants, with MICs for imipenem and carbapenem of greater than 128 micrograms/ml, were selected in vitro from four carbapenem-susceptible (CpmS) clinical isolates of Bacteroides fragilis. The CpmS strains produced very low levels of beta-lactamase activity, which was increased approx. 50- to 100-fold in the CpmR mutants. Isoelectric focussing and enzyme kinetic analysis (Km and Vrel) of the 'carbapenemases' from the CpmR mutants and similarly resistant clinical isolates suggested a close relatedness of the enzymes. A probe covering most of the cfiA gene encoding such an enzyme (Thompson, J.S. and Malamy, M.H. (1990) J. Bacteriol. 172, 2584-2593) hybridized with DNA from the CpmR mutants, their CpmS parental strains as well as clinical CpmR isolates, but not from randomly chosen carbapenem-susceptible strains. The possibility is considered that mutations leading to expression of the silent carbapenemase gene, and thereby to clinically relevant carbapenem resistance, may also occur in the clinical setting.

A collaborative study of French laboratories to assess any evolution of antibiotic resistance within the Bacteroides fragilis group.

Antibiotic susceptibility testing of anaerobes by a same methodology allows the authors to draw up suggestions about the evolution of antibiotic resistance within the B. fragilis group. Cefoxitin resistance rates were stable until 1985 and were slowly increasing later. Until 1985 piperacillin was able to inhibit all tested strains. In 1987 the two groups noticed an increasing resistance to piperacillin (4 to 9%). During the 1970's clindamycin resistance was a minor event (less than 1%) then the resistance rate increased rapidly to 10% in 1980. MICs determinations from 1981 to 1985 demonstrated well that clindamycin resistance was stable at this 10% rate. Since 1987 the clindamycin resistance was again increasing and reached respectively 14 to 19% for the two groups of investigators. Metronidazole has kept a good activity against Bacteroides fragilis group strains but some strains with reduced susceptibility (MIC 2 to 8 mg/l) have been described since 1983. Three strains with MIC greater than 8 mg/l were recently described by one of the groups. Until 1987, the clavulanic amoxicillin combination was able to inhibit all strains of the B. fragilis group but only imipenem remained still active on all investigated strains with no change at all for the values of MIC50 and MIC90 determined by the investigators of this study. All these results emphasize the need for periodical surveys within the B. fragilis group in each country.