Sensitivity to antibiotics of bacteria from nosocomial infections. Evolution in resuscitation services of military hospitals

OBJECTIVE: The aim of this study, conducted in the French Military hospitals, was to monitor the course of the antimicrobial sensibility of bacteria isolated from nosocomial infection in intensive care units. PATIENTS AND METHODS: A prospective study has been conducted from January to December 1998 in all the intensive care units of the French Army. All the non-repetitive strains isolated from nosocomial infection were collected and sent to a reference centre. Antimicrobial susceptibility was determined by the agar dilution method. Beta-lactamase were identified by iso-electro-focalisation. Antibiotics choice and interpretative criteria were those of the "Comite Francais de l'Antibiogramme de la Societe Francaise de Microbiologie". RESULTS: A total of 849 strains are included in this study. Pseudomonas aeruginosa was the most frequently isolated bacterium (20%) followed by Escherichia coli (19%) Staphylococcus aureus (15%), coagulase-negative Staphylococci (CoNS) (11%) and Enterococci (7%). Imipenem was the most effective antibiotic against enterobacteriaceae (336 isolates; 100% susceptibility). Gentamicin (92%), amikacin (92%) third generation cephalosporins (83%), aztreonam (83%) and ciprofloxacin (78%) were also very effective. Resistance to III generation cephalosporins was correlated with an extended spectrum beta-lactamase (BLSE) in 36% of cases. This BLSE could be associated with an over production of the constitutive cephalosporinase. The most frequent species producing BLSE were Enterobacter aerogenes (75% of BLSE) and Klebsiella pneumoniae (17%). Among the 172 P. aeruginosa isolated, antimicrobial susceptibility were respectively: 71% for imipenem, 62%: tobramycin, 60%: amikacin 59%: ciprofloxacin 59% piperacillin + tazobactam, 55% piperacillin, 53%: ceftazidime and 44% for ticarcillin. Seventy per cent of the 96 CoNS and 50.2% of the 126 S. aureus isolated were resistant to methicillin. A strain of S. aureus and 2 CoNS strains had intermediate resistance to teicoplanin. Twenty per cent of the 59 Enterococci strains isolated were resistant to aminopenicillins (10/11 strains of E. faecium), and 9% presented a high level of resistance to gentamicine. One strain of E. faecium was resistant to vancomycin. CONCLUSION: The evolution of the susceptibility to antibiotics in intensive care units reflects the antibiotic pressure and level of cross-transmission. High rates of meticillin-resistance among staphylococci, of resistance to beta-lactams antibiotics among P. aeruginosa and of ciprofloxacin among Enterobacteriaceae are shown in this study. The implementation of appropriate strategies for surveillance and prevention is necessary

A Current Approach to Diabetic Foot Infections.

Foot infections are a common, complex, and serious problem in diabetic patients. Infections usually begin in foot ulcers, which are associated with neuropathy, vasculopathy, and various metabolic disturbances. These infections are potentially limb and sometimes life threatening. Etiologic agents are usually aerobic gram-positive cocci, but chronic or serious infections often contain gram-negative rods and anaerobes. Chronic infections can lead to contiguous bone infection. Diagnosing osteomyelitis may require imaging studies (especially magnetic resonance imaging) and occasionally bone biopsy. In addition to proper cleansing, debridement, and local wound care, diabetic foot infections require carefully selected antibiotic therapy. Serious infections necessitate hospitalization for initial parenteral broad-spectrum antibiotic therapy, but appropriately selected patients with mild infections can be treated as outpatients with oral (or even topical) agents. Initial antibiotic selection is usually empiric; modifications may be needed based on the results of properly obtained cultures and the clinical response. Therapy should be active against staphylococci and streptococci, with broader-spectrum agents indicated if polymicrobial infection is likely. Levels of most antibiotics, except fluoroquinolones, are often subtherapeutic in infected foot tissues. The duration of therapy ranges from a week (for mild soft tissue infections) to over 6 weeks (for osteomyelitis). No single antibiotic agent or combination has proven to be optimal. With appropriate local, surgical, and antimicrobial therapy, most diabetic foot infections can now be successfully treated

Impact of an antibiotic policy on antibiotic use in a paediatric department. Individual based follow-up shows that antibiotics were chosen according to diagnoses and bacterial findings.

Guidelines and clinical Cupertino for rational antibiotic use were implemented in a Norwegian paediatric department in 1994. From 1994 to 1998 the use of antibiotics and expenditures was reduced by 50%. There was an 80% decrease in the use of cloxacillin, a 74% decrease of aminoglycosides and a 59% decrease of cephalosporins. The use of penicillin V and G increased by 14% and ampicillins by 8%. Eight point prevalence studies showed that on average 23% (range 21-38%) of the patients were treated with antibiotics. Penicillins were used in 44% of courses, aminoglycosides in 35% of courses and cephalosporins in 9% of courses. Treatment was mostly adjusted to bacteriological findings. Compliance with guidelines was >90%. Guidelines for rational antibiotic policy and multidisciplinary co-operation lead to reduction in the use and expenses of antibiotics in a paediatric department

Problems of the prophylactic use of antibiotics in cell culture

The article describes the historical development of the prophylactic use of antibiotics in cell culture as well as the effect of antibiotics on cells, i.e. the beta-lactam antibiotic penicillin, the aminoglycosid antibiotics (streptomycin, neomycin, kanamycin, gentamycin) and the polyene macrolids (nystatin, amphotericin B, fungizone). The way in which antibiotics influence the morphology of cells, their degeneration, their death and their functions is summarized. The DNA- as well as the protein-synthesis is affected. By this, multiple metabolic processes are interfered with or changed. This fact should be considered, when cell culture research is concerned. As antibiotics are used in multifold ways, the otherwise standardized conditions in cell culture are no longer comparable. The prophylactic use of antibiotics is rejected for scientific reasons

Impact of antibiotics on conjugational resistance gene transfer in Staphylococcus aureus in sewage.

The growing rate of microbial pathogens becoming resistant to standard antibiotics is an important threat to public health. In order to assess the role of antibiotics in the environment on the spread of resistance factors, the impact of subinhibitory concentrations of antibiotics in sewage on gene transfer was investigated using conjugative gentamicin resistance (aacA-aphD) plasmids of Staphylococcus aureus. Furthermore, the concentration of antibiotics in hospital sewage was measured by high-performance liquid chromatography (HPLC)-electrospray tandem mass spectrometry. Several antibiotics were found to be present in sewage, e.g. ciprofloxacin up to 0.051 mgl(-1) and erythromycin up to 0.027 mgl(-1). Resistance plasmid transfer occurred both on solidified (dewatered) sewage and in liquid sewage in a bioreactor with a frequency of 1.1x10(-5)-5.0x10(-8). However, low-level concentrations of antibiotics measured in sewage are below concentrations that can increase plasmid transfer frequencies of gentamicin resistance plasmids of staphylococci

Prescription and consumption of antibiotics in ambulatory care

OBJECTIVE: This study was conducted to describe changes in prescription practices outside the hospital, to evaluate the adaptation of such prescriptions to current scientific knowledge, and to compare medical practices in France with those in other European countries. METHODS: Data were collected from several sources: analysis of the literature, surveys conducted in the Loiret department and in the Rhone-Alpes region, ten-year health surveys (INSEE), data from the Sentinel network, sales statements from pharmaceutical firms, the Permanent Survey of Medical Prescription (EPPM) of the Medical Information and Statistics (IMS) firm. Comparisons between France, the United Kingdom and Germany were conducted by the French Medicine Agency's Pharmaco-economic Studies and Information Department using data furnished by the IMS firm and by pharmaceutical firms. RESULTS: In France, antibiotic sales increased by a mean annual rate of 2.1%, expressed in antibiotic units, and 2.6%, expressed in turnover (manufacturer price) between 1991 and 1996. The majority of these antibiotics were prescribed for respiratory and ENT infections with a presumed viral etiology such as rhinopharyngitis and acute bronchitis. The results of the different surveys were in agreement showing that antibiotic prescriptions are made in approximately 40% of all consultations for rhino-pharyngitis and in 80% of those for acute bronchitis. Antibiotics were prescribed in more than 90% of cases of pharyngitis whatever the age of the patient. The situation was different for acute middle ear infections as the number of consultations has remained relatively unchanged over the last 10 years while antibiotic prescriptions have strongly increased, reaching 80% of the consultations. The number of consultations for pharyngitis and acute rhino-pharyngitis appears to be greater in France than in the United Kingdom and in Germany. Likewise, the proportion of patients using antibiotics after consulting for presumed viral conditions would be higher in France with different antibiotic classes being used. CONCLUSIONS: There is a gap between official guidelines (product description documents, therapeutic information document good practice guidelines, consensus conferences) and the state of current practices. Excessive and poorly-adapted antibiotic prescription favors the disturbing phenomenon of resistance which is all the more alarming because the emergence of resistant strains is difficult to predict and concern bacteria causing the most common infections. To improve medical practices and achieve a persistent reduction in the use of antibiotics for viral infections, validated recommendations should be distributed to physicians. An effort should be made to prescribe the most appropriate active substance at optimal dose and treatment duration to limit the development of bacterial resistance. In addition, patients and the general public should be informed of the absence of any beneficial effect and the individual and collective risks involved in using antibiotic for viral infections in order to help them better understand and comply to their physician's prescription.

Impact of antibiotic changes in empirical therapy on antimicrobial resistance in intensive care unit-acquired infections.

We conducted a one-year prospective study on intensive care unit (ICU)-acquired infections and antimicrobial resistance patterns in an 18-bed medical-surgical ICU of a tertiary-care university hospital. We divided the study into two six-month periods in order to evaluate the impact of antibiotic changes in empirical therapy on antimicrobial resistance profiles of the principal isolated micro-organisms. In the first period no changes were made to the previously applied empirical antibiotic protocol; at the end of this period we found high rates of methicillin resistance (MR) among staphylococci, 93% for Staphylococcus aureus (69 isolates) and 79% for coagulase-negative staphylococci (CNS) (48 isolates), and of multiple drug resistance for Pseudomonas aeruginosa (57 isolates), in particular 67% resistance to piperacillin/tazobactam (PIP/TZ). We therefore decided to substitute PIP/TZ with imipenem in nosocomial pneumonia and with cefepime plus metronidazole in peritonitis. We also considered the previous use of amoxicillin/clavulanate (AM/CL) at admission in critically ill patients inadequate; we therefore advised that no antibiotics should be given unless fever developed and eventually to replace AM/CL with trimethoprim/sulfamethoxazole (TMP/SMX). At the end of this intervention period, we observed a significant decrease of S. aureus MR (93 vs. 73%, P = 0.003) and of P. aeruginosa resistance to PIP/TZ (67 vs. 29%, P < 0.001). A reduction in MR was also seen in CNS (79 vs. 64%, P = 0.09). Other resistance patterns also improved among staphylococci; in contrast P. aeruginosa resistance to imipenem increased in the second period (24 vs. 41%, P = 0.06). A non-premeditated change of antibiotics in empirical therapy, on the basis of detected resistance patterns, provided promising results in reducing some antimicrobial resistance rates. We believe, however, that antibiotic changes must be tailored to local microbiological situation monitoring, and that a repeated rotation is crucial to limit the emergence of new resistance profiles. Furthermore the adoption of this policy should be accompanied by other infection control practices aimed at reducing antimicrobial resistance and nosocomial infection rates.

An analysis of antibiotic prescriptions from general dental practitioners in England.

The aim of this study was to determine the antibiotics prescribed by general dental practitioners (GDPs). Adult antibiotic prescriptions issued by GDPs from 10 Health Authorities (HAs) in England were analysed. The type of antibiotic prescribed, dose, frequency and duration were investigated. Most of the 17007 prescriptions were for generic antibiotics; nine different antibiotics were prescribed. Many practitioners prescribed antibiotics inappropriately with inconsistent frequency and dose, and for prolonged periods

Prescriptions of systemic antibiotics for children in Germany aged between 0 and 6 years.

Limited information is available about systemic antibiotic use among children in Germany. We therefore assessed prescription patterns by office-based physicians to analyse antibiotic consumption in early childhood. A total of 331 children < 6 years were eligible for inclusion. The number of antibiotic prescriptions, consumed daily doses, number of treatment courses, types of antibiotics and diagnoses for prescribing were determined. The prevalence of systemic antibiotic treatment was 42.9%. Antibiotic consumption was highest between 2 and 3 years of age (55.8%). The percentage of children receiving one, two or three courses of antibiotic treatment was 49.3, 28.2 and 16.2%, respectively. Acute otitis media (32.2%), upper respiratory tract infections (18.9%), tonsillitis (15.9%) and acute bronchitis (15.4%) were principal indications for treatment. Macrolides were most frequently prescribed (48.1%), followed by penicillin V (21.3%), broad-spectrum penicillins (14.3%), sulfonamides (10.5%) and cephalosporins (5.8%). Antibiotics not recommended for particular indication were selected in 5-43% of cases. The considerable prescription of systemic antibiotics to children in many European countries is also the case in Germany. A noteworthy trend emerged for suboptimal prescribing with second-line antibiotics. As such treatment may be associated with the development of bacterial resistance, improved guidelines for antibiotic treatment should be drawn up and enforced

Clinical and community strains of Klebsiella pneumoniae: multiple and increasing rates of antibiotic resistance in Abha, Saudi Arabia.

Klebsiella pneumoniae is the most commonly isolated bacterial species in a maternity hospital in Saudi Arabia. Here, 380 strains isolated in 1997 and 480 strains in 1999 were studied for their resistance antibiograms, using the standardised disc diffusion test. Of 16 antibiotics tested, four in 1997 and six in 1999 were ineffective against > 50% of the respective isolates, and resistance rates to 11 antibiotics increased over the two-year period (P = 0.05-< 0.0001). With resistance rates of < 20%, imipenem, ciprofloxacin, gentamicin and cefotaxime were more effective in 1997; only imipenem and ciprofloxacin remained as effective in 1999. In addition, 105 community strains were tested and > 50% were resistant to four antibiotics. Resistance rates to most antibiotics were lower than those of clinical strains (P = 0.0285-< 0.0001). Imipenem resistance was detected among both clinical and community isolates. Multiresistance was 64.5% in 1997 and 79.2% in 1999 (P < 0.0001), and 83.8% in community strains in 1999. Using the double-disc synergy test, extended-spectrum beta-lactamase (ESBL) was detected in 27.5% of ceftazidime-resistant clinical strains isolated in 1999. Among the clinical strains, seven (65%) and 11 (67.9%) resistance antibiograms occurred frequently in 1997 and 1999, respectively. Such frequency was not observed among community isolates. These findings confirm the alarmingly high rates of multiresistance and the emergence of ESBL-producing strains, highlighting the urgent need to restrict over-the-counter availability of antibiotics, and increase awareness in the local medical community