A risk to himself: attitudes toward psychiatric patients and choice of psychosocial strategies among nurses in medical-surgical units.

Psychiatric patients are liable to stereotyping by healthcare providers. We explored attitudes toward caring for psychiatric patients among 13 nurses working in general hospitals in Ireland. Participants thought aloud in response to a simulated patient case and described a critical incident of a patient for whom they had cared. Two attitudinal orientations were identified that correspond to stereotypical depictions of risk and vulnerability. The nurses described psychosocial care strategies that were pragmatic rather than authentically person-centered, with particular associations between risk-oriented attitudes and directive nursing care. Nurses had expectations likely to impede relationship building and collaborative care. Implications arising include the need for improved knowledge about psychiatric conditions and for access to professional development in targeted therapeutic communication skills.

Investigation of a global collection of nontyphoidal Salmonella of various serotypes cultured between 1953 and 2004 for the presence of class 1 integrons.

In this study, antibiotic resistance profiles, and the presence of class 1 integrons were determined for 108 Salmonella isolates comprising 37 serotypes cultured from a variety of sources between 1953 and 2004. Antibiogram analyses showed that all isolates were resistant to streptomycin/spectinomycin. Molecular analysis revealed that 50% of the collection contained an integrase-encoding gene (int1) and 25% contained class 1 integrons. A Salmonella Wien isolate possessing a complete class 1 integron with a dfrA5-ereA2 gene arrangement within the variable region was characterized.

High-level resistance to moxifloxacin and gatifloxacin associated with a novel mutation in gyrB in toxin-A-negative, toxin-B-positive Clostridium difficile.

OBJECTIVES: To determine the mechanism of high-level resistance to fluoroquinolone antimicrobials in toxin-A-negative, toxin-B-positive (A- B+) Clostridium difficile isolates. METHODS: Following culture 16-23S PCR ribotyping was used to determine genomic relationships between A- B+ C. difficile isolates. Antimicrobial susceptibilities were determined using Etests in the presence and absence of the efflux pump inhibitors reserpine (20 microg/mL), L-phenylalanine-L-arginine-beta-naphthylamide (PAbetaN; 20 microg/mL) and verapamil (100 microg/mL). Genomic regions including the quinolone-resistance-determining-region (QRDR) of gyrA and gyrB were amplified and characterized. RESULTS: PCR ribotyping profiles identified one major cluster of A- B+ C. difficile, universally resistant to the fluoroquinolones tested (ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin and gatifloxacin; MICs > 32 mg/L). All isolates with high-level resistance had a transversion mutation (A-->T) resulting in the amino acid substitution Asp-426-->Val in gyrB. Non-clonal isolates were susceptible to moxifloxacin and gatifloxacin (MICs 0.3 and 0.4 mg/L, respectively) with reduced susceptibility to levofloxacin (MIC 3 mg/L) consistent with the wild-type genotype. The MICs for resistant isolates were not significantly affected by the addition of any of the efflux pump inhibitors. No amino acid substitutions were identified in the QRDR of gyrA. CONCLUSIONS: High-level resistance to fluoroquinolones in A- B+ C. difficile is associated with a novel transversion mutation in gyrB. The emergence of universal resistance in different C. difficile strain types may be a factor promoting outbreaks in hospitals.

Multi-drug resistance in Salmonella enterica: efflux mechanisms and their relationships with the development of chromosomal resistance gene clusters.

Bacterial drug resistance represents one of the most crucial problems in present day antibacterial chemotherapy. Of particular concern to public health is the continuing worldwide epidemic spread of Salmonella enterica serovar Typhimurium phage type DT104 harbouring a genomic island called Salmonella genomic island I (SGI-1). This island contains an antibiotic gene cluster conferring resistance to ampicillin, chloramphenicol, florfenicol, streptomycin, sulfonamides and tetracyclines. These resistance genes are assembled in a mosaic pattern, indicative of several independent recombinational events. The mobility of SGI-1 coupled with the ability of various antibiotic resistance genes to be integrated and lost from the chromosomal resistance locus allows for the transfer of stable antibiotic resistance to most of the commonly used antibiotics and adaptation to new antibiotic challenges. This, coupled with the incidence of increasing fluoroquinolone resistance in these strains increases the risk of therapeutic failure in cases of life-threatening salmonellosis. Fluoroquinolone resistance has largely been attributed to mutations occurring in the genes coding for intracellular targets of these drugs. However, efflux by the AcrAB-TolC multi-drug efflux pump has recently been shown to directly contribute to fluoroquinolone resistance. Furthermore, the resistance to chloramphenicol-florfenicol and tetracyclines in DT104 isolates, is due to interaction between specific transporters for these antibiotics encoded by genes mapping to the SGI-1 and the AcrAB-TolC tripartite efflux pump. The potential for the use of efflux pump inhibitors to restore therapeutic efficacy to fluoroquinolones and other antibiotics offers an exciting developmental area for drug discovery.

Characterization of a collection of Enterobacter sakazakii isolates from environmental and food sources.

Enterobacter sakazakii has emerged as a rare cause of neonatal meningitis, septicemia and enterocolitis. Contaminated infant milk formula (IMF) has been identified as one infection route. A small number of clinical outbreaks have been epidemiologically linked to IMF contaminated post-pasteurization during manufacture and/or mishandled when reconstituted. Currently no agreed standardized typing protocol has been developed to trace E. sakazakii. The objectives of this study were to apply biochemical and genetic methods to characterize 51 environmental and food E. sakazakii isolates and 6 E. sakazakii type strains. Isolates were presumptively identified using biochemical profiles based on API 20E and ID32E methods and by culture on differential selective Druggan Forsythe Iversen (DFI) agar. Identification was subsequently confirmed by real time polymerase chain reaction (PCR). All but one of the isolates was identified as E. sakazakii by biochemical profiling. One isolate was identified as Escherichia vulneris by ID 32E and as Pantoea agglomerans by API 20E. All isolates produced green/blue colonies on DFI medium characteristic of this organism. Real time PCR could differentiate between E. sakazakii, Enterobacter spp. and other Enterobacteriacae. Analysis of RAPD banding patterns revealed 3 major clusters of E. sakazakii. There was a large degree of diversity noted amongst the remaining isolates. Our findings indicate that RAPD may be applied as a useful and reliable tool for direct comparison of E. sakazakii isolates providing traceability through the infant formula food chain.

Antimicrobial resistance in nontyphoidal Salmonella from food sources in Colombia: evidence for an unusual plasmid-localized class 1 integron in serotypes Typhimurium and Anatum.

Seventy-two isolates representing 18 serotypes recovered from various food samples collected in Colombia were tested for antimicrobial susceptibilities. The collection was further characterized for extended-spectrum cephalosporin, aminoglycoside, and tetracycline resistance markers. Multidrug resistant (MDR) isolates were further investigated for class 1 integrons and were evaluated for the presence of conjugative plasmids along with a determination of the incompatibility group by polymerase chain reaction (PCR). Antibiogram analysis showed that the incidence rate of ceftiofur resistance was moderately high (15%). A similar level of resistance to neomycin and oxytetracycline (11% and 10%, respectively) was also observed. There was a high prevalence of gene cassettes as part of one or more class 1 integrons (61%), many of which contained determinants that contributed to the resistance profile. Class 1 integrons identified in MDR Salmonella enterica serotypes Typhimurium and Anatum isolates were characterized. Sequencing identified several incomplete open reading frames (ORFs) as part of a gene cassette (bla-( imp-13 ), dfr7, blr1088, and aac8) along with a complete gene cassette (bla-(oxa2)) in each case. A mosaic of gene cassettes was identical in the two Salmonella serotypes. These integrons were located to a conjugative replicon. Plasmid profiling and incompatibility typing identified three plasmids belonging to Inc groups A/C, P, and W. Our study highlights the role of integrons, contributing to a MDR phenotype that is capable of dissemination to other bacteria.

Antimicrobial resistance in isolates of Salmonella spp. from pigs and the characterization of an S. Infantis gene cassette.

One hundred and seven Salmonella isolates of various serotypes were investigated for resistance to a panel of nine antimicrobial agents by standardized methods. Thirty four isolates were susceptible to the selected antimicrobial agents. Thirty-six (of 107) were resistant to three or more antimicrobial agents and defined as multidrug resistant (MDR). Salmonella Typhimurium was the most resistant serotype. All resistant isolates were examined for the presence of class 1 integrons. Thirty-two integron-associated gene cassettes (of varying sizes) were identified. A 1,000-bp amplicon similar to that flanking the distal region of the Salmonella Genomic Island (SGI)-1 in Salmonella Typhimurium was detected in a majority of the S. Typhimurium isolates in this study. In contrast, a 1,800-bp amplicon was identified in all Salmonella Infantis isolates. This amplicon was completely characterized in one isolate. The presence of class 1 integrons in Salmonella spp. in pigs may be important if these zoonotic pathogens were to enter the food chain.

Characterisation of the nitrile hydratase gene clusters of Rhodococcus erythropolis strains AJ270 and AJ300 and Microbacterium sp. AJ115 indicates horizontal gene transfer and reveals an insertion of IS1166.

The nitrile metabolising strains AJ270, AJ300 and AJ115 were isolated from the same location. The strains have very similar nitrile metabolising profiles. Sequencing of the 16S rRNA gene indicates that strains AJ270 and AJ300 are novel strains of Rhodococcus erythropolis while strain AJ115 is a novel Microbacterium strain very closely related to Microbacterium oxydans and Microbacterium liquefaciens. Analysis of the structure of the nitrile hydratase/amidase gene clusters in the three strains indicates that this region is identical in these strains and that this structure is different to other nitrile hydratase/amidase gene clusters. The major difference seen is the insertion of a complete copy of the insertion sequence IS1166 in the nhr2 gene. This copy of IS1166 generates a 10 bp direct duplication at the point of insertion and has one ORF encoding a protein of 434 amino acids, with 98% homology to the transposase of IS666 from Mycobacterium avium. A gene oxd, encoding aldoxime dehydratase is found upstream of the nitrile hydratase gene cluster and an open reading frame encoding a protein with homology to GlnQ type ABC transporters is found downstream of the nitrile hydratase/amidase genes. The identity of the nitrile hydratase/amidase gene clusters in the three strains suggests horizontal gene transfer of this region. Analysis of the strains for both linear and circular plasmids indicates that both are present in the strains but hybridisation studies indicate that the nitrile hydratase/amidase gene cluster is chromosomally located. The nitrile hydratase/amidase enzymes of strain AJ270 are inducible with acetonitrile or acetamide. Interestingly although a number of Fe-type nitrile hydratases have been shown to be photosensitive, the enzyme from strain AJ270 is not.

Campylobacter.

Species within the genus, Campylobacter, have emerged over the last three decades as significant clinical pathogens, particularly of human public health concern, where the majority of acute bacterial enteritis in the Western world is due to these organisms. Of particular concern are the species, C. jejuni and C. coli, which are responsible for most of these gastrointestinal-related infections. Although these organisms have already emerged as causative agents of zoonoses, several aspects of their epidemiology and pathophysiology are only beginning to emerge. Trends in increasing antibiotic resistance are beginning to emerge with oral antibiotics, which may be the drug of choice for when it is necessary to intervene chemotherapeutically. This review wishes to examine (i) emerging clinical aspects of the disease, such as Guillain Barre syndrome (GBS), (ii) the association between these organisms and poultry as a natural host, (iii) environmental aspects of Campylobacter epidemiology, (iv) the emergence of atypical campylobacters (v) emerging trends in antibiotic resistance, (vi) adoption of modern methods for the detection of campylobacters.

Characterization of a 2.6 kbp variable region within a class 1 integron found in an Acinetobacter baumannii strain isolated from a horse.

OBJECTIVES: A complete gene cassette contained in a class 1 integron from a multidrug-resistant (MDR) isolate of Acinetobacter baumannii cultured from a horse was characterized by molecular methods. METHODS: Template genomic DNA purified from the A. baumannii isolate was investigated by PCR. A gene cassette-associated amplicon was detected and completely characterized. RESULTS: A 2.6 kbp DNA fragment containing four gene cassettes was amplified from the MDR A. baumannii isolate. Sequence analysis showed it was similar to sequences recently reported in Klebsiella pneumoniae, Serratia marcescens and an Escherichia coli plasmid p1658/97 which conferred aminoglycoside resistance. Aminoglycoside resistance-encoding genes aacC1 and aadA1 were located within the 2.6 kbp amplicon, separated by two open reading frames (ORFs) coding for unknown products. This cassette structure (and some variants) was identified in unrelated Acinetobacter spp. from human sources, based on sequence comparisons of the current databases. CONCLUSIONS: Identification of a complete class 1 integron in an equine isolate of A. baumannii suggests that the screening of isolates from animals for these elements should be considered, as this information could influence the selection of chemotherapeutic agents.