[MRSA infection via a staff member with eczema]. / MRSA-besmetting via een medewerker met eczeem.

BACKGROUND: Transmission of MRSA from livestock to humans is rare, but it is advisable to remain alert. CASE STUDY: Following 2 hospital admissions within a month and a half, a 73-year-old patient was found to have become infected with MRSA. The MRSA type was livestock-related. Investigations into contact between the patient and staff revealed that 3 staff members were infected with the same bacteria; one of them had eczema on both hands. Her daughter, who worked intensively with horses, was revealed to be a carrier of the same type of MRSA. CONCLUSION: In order to prevent cross-contamination with MRSA it is essential to comply completely with hand hygiene requirements; this also applies to members of staff with skin infections such as eczema. Patient-related activities should be adapted if necessary. The company doctor plays an important role in this process.

Nocardia farcinica as the causative agent in a primary psoas abscess in a previously healthy cattle inspector.

A 42-year-old, previously healthy cattle inspector presented with a 7-day history of fever, a painful left knee, malaise and muscular pain. He did not suffer from an underlying disease, nor was he immunocompromised. After 12 days of hospitalization, a unilocular abscess in the left psoas muscle was diagnosed. Nocardia farcinica was isolated from the aspirate. No connection with his work could be demonstrated. The patient was successfully treated with trimethoprim-sulfamethoxazole for 11 months.

Antibiotic use and resistance of Streptococcus pneumoniae in The Netherlands during the period 1994-1999.

Antibiotic use in The Netherlands during the period 1994-1999 is described in relation to the resistance of routine isolates of Streptococcus pneumoniae. The average antibiotic use in the study period was 3.4 defined daily doses per 1000 persons per day (DDD/1000/day) penicillins, 0.066 DDD/1000/day beta-lactams other than penicillins, 2.3 DDD/1000/day tetracyclines and 0.71 DDD/1000/day trimethoprim and sulphonamides, without apparent rise or decline. In contrast, the use of macrolides doubled from 0.51 DDD/1000/day in 1994 to 1.0 DDD/1000/day in 1997 and stayed at 1.07 DDD/1000/day in 1998 and 1999. In 1994 the first pneumococci isolated from patients showed 0.7% resistance to penicillin (intermediate plus full resistance), 2.5% to erythromycin, 4.2% to co-trimoxazole and 4.7% to tetracycline. In 1999 first isolates showed 1.5% resistance to penicillin, 3.8% to erythromycin, 4.4% to co-trimoxazole and 6.6% to tetracycline. The modest but significant rise in the resistance to erythromycin may have been caused by the increased use of macrolides in the years 1994-1997. The rise in resistance to penicillin seemed not to be related to increased beta-lactam use.

[High sensitivity of Escherichia coli to antimicrobial agents used for first-line treatment of urinary tract infections; results of an examination of feces of healthy subjects in Friesland]. / Goede gevoeligheid van Escherichia coli voor antimicrobiële middelen gebruikt voor de behandeling van urineweginfecties in de eerste lijn; resultaten van een fecesonderzoek onder gezonde personen in Friesland.

OBJECTIVE: To determine the basic sensitivity of Escherichia coli in the province of Friesland, the Netherlands, to antimicrobial agents used by general practitioners to treat urinary tract infections. DESIGN: Inventory. METHOD: Fifty general practitioners in the province were asked in 1999 to have faeces submitted by patients who had not been using antibiotics for at least one month. E. coli was isolated from the faeces using an elective medium. The proportions of resistance were compared with those of strains isolated in urine sent for examination to Friesland Public Health Laboratory by a clinic, outpatient department, general practice or nursing home. RESULTS: The sensitivities were tested of 240 strains from 240 healthy subjects (73 males and 167 females; mean age 47 years (range 0-84)). The proportions of strains resistant to the agents tested were as follows: nitrofurantoin: 0.8%, trimethoprim: 10%, co-trimoxazole: 10%, amoxicillin: 15%, amoxicillin-clavulanic acid 0.4%. Forty-eight per cent of the strains showed intermediate susceptibility to amoxicillin, 63% to amoxicillin/clavulanic acid. The resistance was lower than in isolates submitted for examination from general and specialist practices. CONCLUSION: The antimicrobial agents mentioned are still useful for treatment of urinary tract infections in the general practice.

Prospective randomised comparison of single-dose versus multiple-dose cefuroxime for prophylaxis in coronary artery bypass grafting.

To assess the efficacy of single-dose antibiotic prophylaxis in coronary artery bypass grafting, 1,016 consecutive patients were prospectively randomized to receive either a single dose or a three-day course of cefuroxime. Nine patients (0.9%) died within seven days; no death was caused by infection. For various reasons 163 other patients were not evaluable. Therefore, 844 patients were evaluated. Patients in group A (n = 419) received 20 mg/kg cefuroxime intravenously at induction of anaesthesia; group B (n = 425) received the same dose followed by 750 mg t.i.d. for three consecutive days. Both groups were comparable regarding all risk factors. The efficacy of the prophylactic regimens was evaluated by comparison of occurrence of wound infection in both groups. No significant differences in wound infection were observed between the two treatment groups: sternal site infection in the single-dose prophylaxis group was 14% versus 13% in the three-day course group; donor site infection occurred in 38% versus 39%. It is concluded that in coronary artery bypass grafting a single dose of cefuroxime is as effective as a three-day course in the prevention of wound infection.

[Typing of methicillin-resistant Staphylococcus aureus strains for epidemiological studies using the polymerase chain reaction]. / Typering van meticilline-resistente Staphylococcus aureus-stammen voor epidemiologisch onderzoek met behulp van de polymerase-kettingreactie.

OBJECTIVE: To determine whether polymerase chain reaction (PCR) fingerprinting can be used to gain insight into the epidemiology of methicillin resistant Staphylococcus aureus (MRSA). DESIGN: Retrospective DNA analysis of MRSA strains. BACTERIAL STRAINS: MRSA strains were collected in two Dutch and one Belgian hospital (Reinier de Graaf Gasthuis, Delft; St. Antonius Ziekenhuis, Nieuwegein; St. Jan Ziekenhuis, Brugge). METHODOLOGY: MRSA DNA was isolated by standard procedures. Differences in genomic organisation were detected with the aid of exponential enzymatic synthesis of intrinsically variable DNA domains. This so-called PCR fingerprinting, a relatively new technique, was performed in direct comparison with phage typing. The latter is the current golden standard for S. aureus typing. RESULTS: The results of both PCR fingerprinting and phage typing appeared to be useful for strain identification. All results were consistent with other epidemiological data. CONCLUSION: Genotyping MRSA with PCR fingerprinting is complementary to phage typing. In some instances PCR fingerprinting is even to be preferred to the other technique. PCR fingerprinting is well suited for the analysis of MRSA spreading.

Long-standing bacteremia caused by oral Actinobacillus actinomycetemcomitans in a patient with a pacemaker.

A case of symptomatic Actinobacillus actinomycetemcomitans bacteremia in a patient with an implanted pacemaker is presented. Attacks of fever occurred for at least 1 year. Oral examination revealed a mild form of periodontitis. A. actinomycetemcomitans was isolated from several oral sites. DNA fingerprinting of strains from the blood and the oral cavity showed identical profiles. This finding strongly suggests that the oral cavity was the primary source of A. actinomycetemcomitans bacteremia in this case. The patient was treated with the combination of metronidazole plus amoxicillin for 7 days, which resulted in a rapid cure and elimination of A. actinomycetemcomitans from the blood and the oral cavity.

Bacteroides and Staphylococcus glycocalyx: chemical analysis, and the effects on chemiluminescence and chemotaxis of human polymorphonuclear leucocytes.

Glycocalyx (or slime), which is an important virulence factor of many pathogenic bacteria, was isolated from Bacteroides fragilis, Bacteroides thetaiotaomicron and Staphylococcus epidermidis. Organisms were grown for 24 h in a chemically defined, dialysable liquid medium. Bacteria were centrifuged and the supernatant was concentrated and dialysed against distilled water. Total carbohydrate and protein were estimated using standard methods. Thin layer and gas-liquid chromatography of trifluoro acetic acid hydrolysed and non-hydrolysed samples provided evidence for the presence of polysaccharide, the absence of nucleic acids and lipopolysaccharide and for the identification of the individual sugar residues. Glucose, mannose and galactose (B. fragilis), glucose (B. thetaiotaomicron), and glucose and heptose (S. epidermidis) were the sugar residues detected. Uronic acid and hexosamine were detected in all species. Glycocalyx preparations (1 mg/ml) from Bacteroides and Staphylococcus significantly inhibited the chemiluminescence and chemotactic responses of viable human polymorphonuclear leucocytes (PMNL), but were not toxic for PMNL.

Role of antibodies and antibiotics in aerobic gram-negative septicemia: possible synergism between antimicrobial treatment and immunotherapy.

Recovery from gram-negative septicemia depends on the successful joint action of antibiotics and host defense mechanisms. The possible enhancement of host defense with either immunotherapy or antibiotic treatment has been the subject of numerous investigations. Because of the great similarity of core epitopes within different species of Enterobacteriaceae, most studies have focused on the development of cross-reactive and/or cross-protective antibodies to these common epitopes. The majority of strains that cause severe gram-negative septicemia, however, possess a complete O antigen (and often a K antigen) that may camouflage the common antigenic determinants. Antibodies to these common antigens therefore may be unable to recognize their targets. Subinhibitory concentrations of certain antibiotics have been shown to alter surface structures of Enterobacteriaceae to such an extent that the structures no longer camouflage underlying epitopes, allowing binding of cross-reactive or cross-protective antibodies to these epitopes. Thus antibiotics and antibodies may synergistically fight infection.

Immunization of mice with antibiotic-treated Escherichia coli results in enhanced protection against challenge with homologous and heterologous bacteria.

The murine immune response to Escherichia coli exposed to subminimal inhibitory concentrations of four antibiotics was investigated. Groups of mice were injected for 8 weeks with formalin-killed bacteria and subsequently challenged with 10 x LD50 of viable E. coli. Mice receiving saline only (controls) died within 24 h. The mortality of mice immunized with ciprofloxacin-treated E. coli was significantly lower than that of mice immunized with E. coli untreated or treated with other antibiotics. Sera from mice immunized with ciprofloxacin-treated bacteria showed better bacteriostatic capacity and enhanced production of antibodies that bound to homologous and heterologous lipopolysaccharide isolated from several smooth and rough gram-negative strains. The better protection observed in mice immunized with ciprofloxacin-treated E. coli was probably due to an enhanced production of antibodies to epitopes on lipopolysaccharide that became better exposed and so more accessible after treatment with ciprofloxacin.

Effect of sub-minimal inhibitory concentrations of ciprofloxacin and fleroxacin on the bacterial capsular antigen and opsonophagocytosis by human polymorphonuclear leukocytes.

We have studied the effect of sub-minimal inhibitory concentrations (sub-MIC) of ciprofloxacin and fleroxacin on capsulated (K+) and non-capsulated (K-) Gram-negative bacilli (Escherichia coli O1:K1, O7:K1, O1:K-, O7:K-, and Klebsiella oxytoca) as well as on Staphylococcus aureus and we investigated the interaction of antibiotic pretreated bacteria with human serum and polymorphonuclear leukocytes (PMN). Following overnight growth in the presence of 1/2 MIC of the antibiotics, bacteria were opsonized in human serum and incubated with PMN. Opsonophagocytosis was quantified as the ratio of uptake by PMN of radioactively labeled bacteria. Ciprofloxacin and fleroxacin enhanced the phagocytosis rate of E. coli K+ strains (control 5-10%; 1/2 MIC of ciprofloxacin and fleroxacin 70-80%) of K. oxytoca (control O-2%; 1/2 MIC of ciprofloxacin and fleroxacin 35-40%) as well as of Staph. aureus (control 5-10%; 1/2 MIC of the antibiotics 35-40%). Opsonophagocytosis of K- strains was not altered. The enhancement of opsonophagocytosis was a complement dependent process. Exposure of capsulated E. coli to ciprofloxacin as well as to fleroxacin resulted in decreased amounts of the capsular antigen.

A double-blind comparison of low-dose ofloxacin and amoxycillin/clavulanic acid in acute exacerbations of chronic bronchitis.

The efficacy and safety of ofloxacin 400 mg once daily and amoxycillin/clavulanic acid 500/125 mg three times daily were compared in a double-blind manner in patients with an acute exacerbation of chronic bronchitis. Of 102 patients enrolled, 95 (93%) could be assessed for effectiveness. Treatment success was achieved in 41 (84%) of 49 patients in the ofloxacin group compared with 41 (89%) of 46 patients in the amoxycillin/clavulanic acid group. One patient who received ofloxacin and four patients in the amoxycillin/clavulanic acid group stopped medication because of unacceptable side effects. Microbiological results were evaluable in 47% of the patients. Predominant initial pathogens were Haemophilus influenzae, Streptococcus pneumoniae, sometimes in combination, and less frequently Branhamella catarrhalis. In two patients with clinical failure, randomized to ofloxacin, the initial pneumococcal strains persisted in the sputum after treatment.

Enhanced phagocytosis of encapsulated Escherichia coli strains after exposure to sub-MICs of antibiotics is correlated to changes of the bacterial cell surface.

The influence of five antibiotics (netilmicin, ceftriaxone, cefepime, fleroxacin, and ciprofloxacin) on capsular polysaccharide distribution and on opsonophagocytosis by human polymorphonuclear leukocytes of unencapsulated and encapsulated Escherichia coli strains was studied. Unencapsulated E. coli strains were readily opsonized in serum and easily ingested by polymorphonuclear leukocytes, and antibiotics did not further enhance the phagocytosis rates. In contrast, encapsulated bacteria were poorly opsonized in human serum, and phagocytosis was enhanced after overnight exposure to 0.5x the MICs of the antibiotics, with the exception of cefepime. Incubation of unencapsulated as well as encapsulated bacteria in complement-inactivated serum markedly reduced the bacterial uptake by polymorphonuclear leukocytes regardless of the presence of antibiotics. Slide agglutination assays, performed either with a monoclonal antibody for capsular polysaccharide or with an antiserum raised against the stable unencapsulated mutant E. coli O7:K-, showed reduction but not lack of the capsular polysaccharide of encapsulated E. coli O7:K1, and better exposure of subcapsular epitopes, after incubation with 0.5x the MICs of antibiotics. Flow cytometric analysis of encapsulated E. coli exposed to netilmicin, ciprofloxacin, and fleroxacin revealed that the reduction in capsular material was homogeneous among the bacterial population. Treatment with cefepime and ceftriaxone induced two populations of bacteria that differed in the amount of K antigen present. These results indicate that sub-MICs of netilmicin, ceftriaxone, fleroxacin, and ciprofloxacin influenced complement-mediated opsonization, probably due to changes in the capsular polysaccharide structure.

Serious bacterial cellulitis of the periorbital area in two patients with systemic lupus erythematosus.

We describe the occurrence of bacterial cellulitis in the periorbital area of 2 patients with systemic lupus erythematosus (SLE). In both patients the antibacterial activity of polymorphonuclear leucocytes was normal. The opsonic capacity of serum was defective in one patient (corresponding to decreased levels of the 4th component of complement) and normal in the other. Seemingly minor bacterial infections of the skin in patients with SLE should warrant aggressive antimicrobial treatment.

Carumonam enhances reactivity of Escherichia coli with mono- and polyclonal antisera to rough Escherichia coli J5.

Escherichia coli O111 reacts only slightly with antiserum to its rough mutant E. coli J5 in an enzyme-linked immunosorbent assay. When E. coli O111 was grown in the presence of sub-MICs of the monocyclic beta-lactam antibiotic carumonam, however, the enzyme-linked immunosorbent assay titer increased from 1,280 to 81,920. When the bacteria were grown in the presence of carumonam, the titer that was obtained with antiserum against E. coli O111 was not affected. This reaction was abolished after this antiserum was absorbed with E. coli J5 in the case of the carumonam-treated strain, whereas this absorption did not affect the reaction with E. coli O111. Thus, the O-antigenic side chain of E. coli O111 seems to be affected if this strain is cultured in the presence of carumonam. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a relative loss of the O polysaccharide in E. coli O111 when this strain was grown in the presence of carumonam. Also, a much stronger reaction of the antibiotic-affected lipopolysaccharide with a monoclonal antibody against E. coli J5 lipopolysaccharide was shown in immunoblots. The results of this study indicate that there is a synergism between certain antibiotics and monoclonal antibodies, something that could have clinical implications.

Do quinolones really augment the antifungal effect of amphotericin B in vitro?

The minimum inhibitory concentrations (MICs) for amphotericin B and the quinolones norfloxacin and ciprofloxacin against 30 clinical isolates of Candida albicans were determined in various liquid media. Interaction studies were carried out to investigate a possible synergistic action of the quinolones on the antifungal effect of amphotericin B. No interaction between the drugs studied was observed in any of the media used.