Local outbreak of quinolone-resistant but ceftriaxone-susceptible gonorrhoea in a region of Denmark

INTRODUCTION

During the past decade, gonorrhoea has been on the rise in several European countries, and along with a decreasing susceptibility to currently used antimicrobial agents, there are worldwide concerns about future case management. The objective of the present study was to describe the antibiotic resistance of gonococci and physicians' adherence to national Danish guidelines in the Region of Northern Jutland (RNJ) from 2000 to 2010.

MATERIAL AND METHODS

All incident episodes of microbiologically confirmed Neisseria gonorrhoeae infections from 2000 to 2010 were included. Data were retrieved from the Laboratory Information System at the Department of Clinical Microbiology, Aalborg University Hospital. Clinical data on hospital-treated patients were retrieved from medical records. General practitioners and patients were not contacted.

RESULTS

A total of 296 incident episodes in 285 patients were included. The majority of infections were observed in men (71%). The annual incidence increased five-fold during the study period and peaked in 2009. Most infections were acquired in Denmark. 13 per cent had swabs performed according to guidelines from the Danish National Board of Health. Quinolone-resistance fluctuated between 13% and 93%. The highest level was observed in 2009. No isolates were resistant to ceftriaxone and we observed no treatment failure.

CONCLUSION

We have described a local outbreak of quinolone-resistant but ceftriaxone-susceptible gonorrhoea in the RNJ. Our study highlights the importance of microbiological confirmation, treatment and follow-up of gonorrhoea in accordance with national guidelines.

FUNDING

not relevant.

TRIAL REGISTRATION

not relevant.

[The quality of susceptibility examinations of urine in general practice is generally good]

In Denmark, many microbiological tests (microscopy, culture and susceptibility examinations) are done in general practice for the diagnosis of urinary tract infections (UTI). In 2006, the costs of susceptibility examinations were 28 million DKK. Some regional health authorities have established a program for quality assessment. National quality requirements for susceptibility examinations have already been established. The clinical microbiological departments send simulated urines with bacteria of common UTI strains. The specimens are examined in general practice with routine methods. The results for a two-year period of susceptibility examinations are reported. Generally, the quality criteria were met.

Symptoms and signs in culture-proven acute maxillary sinusitis in a general practice population

The objective of this study was to assess symptoms and signs in patients with maxillary sinusitis and a bacteriological diagnosis obtained by sinus aspiration or lavage. Designed as a prospective cohort study in general practice, the study included 174 patients, aged 18-65 years, suspected of having acute maxillary sinusitis by their general practitioner. The main outcome measures were the independent association of symptoms, signs, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) concentration and confirmed infection with the predominant bacterial pathogens Streptococcus pneumoniae and Haemophilus influenzae. The predominant organisms found in patients with acute maxillary sinusitis were S. pneumoniae and H. influenzae. Body temperature >38 degrees C and maxillary toothache were significantly associated with the presence of S. pneumoniae and H. influenzae. Positive bacteriological culture results were significantly associated with increasing ESR and CRP values. None of the symptoms and signs, with the exception of body temperature >38 degrees C and maxillary toothache, were particularly sensitive indicators of the specific aetiology in patients with acute maxillary sinusitis. Elevated ESR and CRP values were significantly associated with positive bacteriological culture results. On the other hand, absence of these symptoms and signs did not exclude the presence of acute maxillary sinusitis.

[Gastrointestinal symptoms predominant in refugee children with malaria]

We present three cases of malaria in refugee children newly arrived from Sub-saharan Africa. Only one of the three children had fever and all had high parasite loads (2,5-14% parasitemia). Malaria is an important differential diagnosis in refugees from endemic areas, regardless of whether they present with fever.

Bedside diagnosis of imported malaria using the Binax Now malaria antigen detection test

Malaria may be misdiagnosed in non-endemic countries when the necessary experience for rapid expert microscopy is lacking. Rapid diagnostic tests may improve the diagnosis and may play a role as a bedside diagnostic tool. In a multicentre study we recruited patients suspected of malaria over a period of 14 months. The Binax Now Malaria rapid test was used at the bedside and in the clinical microbiology laboratory. The training of clinical staff was monitored and their experience with the use of the test was recorded. 542 patients were included, 80 of whom had malaria diagnosed by microscopy. The rapid test used at the bedside had a sensitivity of 88% for the detection of P. falciparum compared to 95% when the test was performed in the microbiology laboratory. The risk of technical problems and invalid tests was highest when the test was used at the bedside. The rapid diagnostic test may be useful for the diagnosis of P. falciparum malaria when used by routine laboratory staff, but could lead to misdiagnoses when used at the bedside. Microscopy is still essential in order to identify the few missed diagnoses, to determine the degree of parasitaemia, and to ensure species diagnosis, including mixed infections.

Culture of multiple peroperative biopsies and diagnosis of infected knee arthroplasties

Prosthetic joint infections remain difficult to diagnose. In 1981, Kamme & Lindberg described a diagnostic procedure with five peroperative biopsies in patients with total hip arthroplasty (Clin Orthop Relat Res 1981;154:201-7). Its usefulness, however, has not been ascertained for other prosthetic joints undergoing surgical revision. Therefore, we undertook a retrospective study of 120 surgical revisions in 118 patients with knee arthropasties where such biopsies had been obtained. Cases were categorized into three groups based on information available prior to revision and peroperative inspection: prosthetic joint infection (n = 26), aseptic loosening (n = 58), and mechanical problems (n = 36). Fifteen sets were positive, 13 had significant growth (i.e. > or =3 biopsies with the same microbe/s), and 2 had insignificant growth (< or =2 positive biopsies). Excluding the group with a mechanical problem, the sensitivity for infection was 12/26 (46%), the specificity 58/58 (100%), the positive predictive value 12/12 (100%), and the negative predictive value 58/72 (81%). In the group with infection there was a trend towards less exposure to antibiotics in cases with positive cultures than cases with negative cultures. The Kamme & Lindberg procedure is applicable also to knee arthroplasties, but the low sensitivity and negative predictive value underline the need for new diagnostic methods.

Detection of candidaemia in high risk patients: can yield of blood cultures be improved by blind subculture?

Rapid detection of candidaemia is crucial for timely antifungal chemotherapy. However, the sensitivity of automated blood culture (BC) systems has been questioned. Blind subculture might increase detection rate and possibly also reduce time to detection of candidaemia. This retrospective study aimed to evaluate the efficacy of blind subcultures in patients deemed at high risk of candidaemia. BCs were processed by the BacT/Alert BC system, and during a 5-y period (1998-2003) subculture on the third d of incubation was performed for patients selected by clinical and microbiological assessment. A total of 79,165 BCs were drawn during the study period. 2154 BCs from 285 patients were selected for subculture. 103 (4.8%) BCs from 52 patients were yeast positive; 71 were detected positive prior to the planned subculture, 25 were positive on subculture, and 7 were negative on subculture, but became positive during further incubation. The 25 BCs positive on subculture originated from 14 patients, 11 of whom had already been diagnosed with candidaemia during the previous 14 d. Thus, a primary diagnosis of candidaemia was obtained by subculture in only 3 (1.1%) of the 285 patients selected. In conclusion, in our clinical setting blind subculture did not materially increase the detection of candidaemia, but helped to document persistent infection in a subset of cases.

[Nosocomial infections with penicillin-resistant Streptococcus pneumoniae. Four clusters with pneumococci serotype 9V]

INTRODUCTION

The objective was to alert Danish hospital physicians to the risk of nosocomial spread of penicillin-resistant Streptococcus pneumoniae (PRP).

MATERIALS AND METHODS

The study was conducted in the County of Northern Jutland during the 3-year period 1996-1998. Data on isolates of PRP were retrieved retrospectively from a computerised laboratory information system, and additional information was obtained from patients' charts and notes by infection control nurses.

RESULTS

Four incidents of likely nosocomial spread of PRP, serotype 9V, were identified in departments of medicine or pulmonary diseases. Clusters included two to four patients. The eleven patients were 53 to 92 years of age, and all but one had severe underlying pulmonary disease or a malignant disorder. During the same period, we found that among pneumococcal bacteraemias of definite origin 8.9% (95% confidence limits 5.9-12.9%) was nosocomial.

CONCLUSION

The risk of nosocomial spread of pneumococci, including PRP, should be acknowledged. A policy of isolation should be implemented for patients with PRP; isolation precautions should also be considered for patients with a previous isolate of PRP if readmitted, as such patients may become chronic carriers.

Rapid immunodiagnosis of streptococci and enterococci in blood cultures

We evaluated a procedure for rapid identification of blood culture isolates of pneumococci, enterococci and beta-haemolytic streptococci groups A, B, C, and G. Immunological tests were applied directly to blood culture medium and included a quellung reaction for pneumococci, and latex agglutination tests (LAT) for pneumococcal antigen and Lancefield antigens A, B, C, D and G. During a one-year trial period with approximately 12,000 blood culture sets (BacT/Alert, Organon-Teknika), 208 sets showed pure growth of gram-positive cocci in pairs or chains by direct microscopy. Overall, a correct diagnosis was noted for 103 (63.2%, 95% CI: 55.3-70.6%) of 163 sets yielding pneumococci, beta-haemolytic streptococci, or enterococci. A procedure excluding Lancefield antigens only A, B, and D was implemented during a one-year follow-up period. With this simplified procedure positive and negative predictive values, respectively, were 1.00 and 0.87 for pneumococci, 1.00 and 0.94 for beta-haemolytic streptococci group A, 0.60 and 1.00 for beta-haemolytic streptococci group B, and 0.91 and 0.88 for enterococci. We conclude that rapid identification of gram-positive cocci is feasible and may improve the information given to clinicians at the first notification of positive blood cultures.

Ribotyping of strains of Moraxella (Branhamella) catarrhalis cultured from the nasopharynx and middle ear of children with otitis media

Moraxella (Branhaomella) catarrhalis is frequently present in the nasopharyngeal microflora of small children, especially during episodes of acute otitis media . By means of ribotyping (restriction endonuclease analysis of chromosomal DNA combined with rRNA probing), we studied the genetic heterogeneity of 78 cultures of M. catarrhalis obtained from different localities in the nasopharynx of nine young children with secretory otitis media. Using HindIII and PstI as endonucleases, five different ribotypes were recognized, representing at least five different genotypes of M. catarrhalis. The distribution of these types was found to be almost identical to the distribution among 16 M. catarrhalis strains cultured from middle ear exudates of 16 children with acute otitis media. Ribotype HAPA was found in two-thirds of all the cultures investigated, and 44% of the children harboured more than one ribotype in the nasopharynx at the same time. The vast majority of the nasopharyngeal M. catarrhalis cultures were beta-lactamase positive. One child had both a HAPA ribotype, beta-lactamase-negative strain in the nasopharyngeal secretions, and HAPA ribotype, beta-lactamase-positive strains at the entrance of the eustachian tube, the nasopharyngeal tonsils, the folds of the nasopharyngeal tonsils and the oropharynx. All except one of the M. catarrhalis strains cultured from middle ear exudates were beta-lactamase positive.

Aminoglycoside resistance mechanisms in Enterobacteriaceae and Pseudomonas spp. from two Danish hospitals: correlation with type of aminoglycoside used

Sixty-two aminoglycoside-resistant Gram-negative enteric bacteria were isolated over a 3-year period from two hospitals (Bispebjerg and Esbjerg) among a total of almost 270,000 isolates. These hospitals were selected because of their different aminoglycoside policies during the years investigated. At Bispebjerg Hospital the principal aminoglycoside used was tobramycin, while gentamicin was the first choice at Esbjerg Hospital. Escherichia coli was the most frequently found aminoglycoside-resistant species. Among the 61 aminoglycoside-resistant strains studied, resistance was due to aminoglycoside-modifying enzymes in all except two Xanthomonas maltophilia strains. The ANT(2") enzyme occurred significantly more often at Esbjerg Hospital (p = 0.001), while enzymes of the AAC(3) or AAC(6') moieties were more common, but not significantly so, at Bispebjerg Hospital. The phenotypic pattern of aminoglycoside resistance, as determined by disc diffusion, correlated 100% with the ANT(2") and AAC(3)-V (the two most common enzymes among the isolates) genotype of the organisms as established using DNA probes. Median minimum inhibitory concentrations (MICs) (mg/l) for clinically utilized aminoglycosides were: amikacin (1.6), gentamicin (25.0), kanamycin (50.0), netilmicin (1.6-25.0) and tobramycin (12.5-50.0). Isolates from Bispebjerg Hospital revealed significantly higher MICs for netilmicin and tobramycin (p < 0.01) as compared to isolates from Esbjerg Hospital.

Coagulase-negative Staphylococci in Danish blood cultures: species distribution and antibiotic susceptibility

The distribution and antibiotic susceptibility of coagulase-negative staphylococci (CoNS) isolated from blood cultures was examined in samples from hospitals covering most of Denmark. A total of 499 CoNS isolates were detected in 477 blood cultures from 340 patients and speciated as Staphylococcus epidermidis, 285; Staphylococcus hominis, 61; Staphylococcus haemolyticus, 43; Staphylococcus warneri, 12; Staphylococcus cohnii, 7; Staphylococcus saprophyticus, 4; Staphylococcus capitis, 2 and Staphylococcus lugdunensis, 1. Seventy-eight isolates could not be identified to species level and six were Micrococcus spp. In 108 (22.6%) blood culture sets, more than one CoNS strain were found, as detected by species identification, antibiogram and biotyping. Significantly more blood cultures from patients in university hospitals were drawn from central venous catheters. Comparing university and non-university hospitals, the overall antibiotic susceptibility among CoNS was only slightly different, except for methicillin and amikacin. The prevalence of methicillin-resistant strains was 35.1% in the university hospital strains vs. 25.3% in the non-university hospital strains. The overall prevalence of methicillin resistance was 32%. Great geographic variation in both species distribution and antibiotic resistance was observed. The high prevalence of S. epidermidis makes subtyping of this species important.

The impact of the first notification of positive blood cultures on antibiotic therapy. A one-year survey

The impact on antibiotic therapy of the first notification of positive blood cultures was assessed for 735 episodes of bacteraemia detected during 1992 in the County of Northern Jutland, Denmark. A primary focus of infection was defined in 498 episodes, the urinary tract being the most frequent (n = 182, 25%). Twenty-nine patients (3.5%) had died prior to the initial contact. In 12 episodes antibiotic therapy had either been stopped or data were not available, leaving 694 episodes for further assessment. In 567 episodes antibiotic therapy had been started prior to the initial contact, the most frequent regimen being ampicillin or an ampicillin-aminoglycoside combination (295 episodes), whereas cephalosporins, thienamycin, and fluoroquinolones were seldom used (41 episodes). The ongoing antibiotic coverage was deemed appropriate in 418 episodes (60%), non-optimal in 90 (13%), and lacking in 186 (27%). The notification of positive blood cultures elicited changes in antibiotic therapy in 315 episodes (45%), including commencement of antibiotic therapy in 127 (18%). Thus, blood culture results have a measurable impact on antibiotic therapy.

[Resistant gram-negative bacteria at seven intensive care units in Denmark]

A prospective study on the prevalence of resistance to 16 antibiotics in 704 Gram-negative bacteria isolated from seven intensive care units was undertaken in 1990. A microtitre panel carrying 16 antibiotics was used for susceptibility testing. The study revealed minor differences in resistance between the participating centres. The overall resistance was relatively low in Denmark, but there was increased resistance among E. coli from intensive care units compared to E. coli isolates from bloodcultures collected in 1988. At one centre the susceptibility of P. aeruginosa to gentamicin was slightly lower than at other centres, indicating a minor outbreak during the collection period. P. aeruginosa and Enterobacteriaceae with inducible production of beta-lactamases showed cross-resistance between penicillins and cephalosporins, but not between penicillin/cephalosporins and imipenem gentamicin or ciprofloxacin. The resistance among the repeated isolates of inducible Enterobacteriaceae was slightly higher than among the initial isolates indicating acquisition of resistance or selection of resistant mutants.

[Ampicillin-resistant Haemophilus influenzae. Prevalence in isolates from Danish children]

The prevalence of ampicillin-resistance was assessed among a total of 2766 strains of H. influenzae isolated from lower respiratory tract secretions, middle ear secretions, spinal fluid specimens, and blood cultures from children 0-15 years of age tested in two separate counties in Denmark during the period from 1986 to May, 1993. All strains were tested for susceptibility to ampicillin with disc or tablet diffusion technique and strains were examined for beta-lactamase production with a chromogenic cephalosporinase test. In the county of Northern Jutland the rate of beta-lactamase production in non-encapsulated H. influenzae was 2.5% in 1986 rising to 9.3% in 1993. The rate of beta-lactamase production in H. influenzae type b was 4.1% without any rise. In the county of Copenhagen the rate of beta-lactamase production in non-encapsulated H. influenzae rose from 6.3% in 1986 to 10.6% in 1992. In 1993 a further increase to 20.7% was noticed. This year the number of specimens sent to the laboratory and the number of H. influenzae isolated were lower compared to previous years. Thus a different selection of patients may explain the increase in the rate of beta-lactamase production in 1993. The rate of beta-lactamase production in H. influenzae type b was 8.5%. No strains were resistant to ampicillin in diffusion test other than the beta-lactamase producers.

[Pseudomonas bacteremia developing after whirlpool bath]

Whirlpools may be responsible for transmission of microbial infections among the bathers if the technical hygienic conditions in the care of the bath are not observed. Two cases of infection with Pneudomonas bacteria were observed after use of whirlpools in a deluxe summer chalet. On the basis of the documented cases, the necessity for specific requirements concerning the installation, running and control of whirlpools used commercially should be considered. In their advisory brochures, the responsible authorities should ensure that the requirements made concerning whirlpools should be intensified so that these baths in summer chalets which are rented out should be subject to public control. Owners and users of whirlpools should be aware of the importance of meticulous hygiene in their care.

[Prosthetic valve endocarditis caused by Haemophilus parainfluenzae]

A case of endocarditis preceded by dental treatment without prophylactic antibiotics and caused by Haemophilus parainfluenzae in a patient with a biological heart valve prosthesis is described. This bacteria grows slowly in the usual blood culture media and, because of this, the etiological diagnosis was not established until after incubation for 11 days. Blood cultures from patients suspected of having endocarditis should be incubated for longer than the usual five to seven days. Close cooperation between the clinical microbiologist and clinicians is necessary so that important findings are not overlooked. Dental treatment of patients with heart valve prostheses should always take place under antibiotic prophylaxis.

Imported pedal chancroid: case report

A man aged 22 who had returned from the Fiji Islands to Denmark had chancroid on the left foot, but no history or sign of primary genital infection. The pedal location only is an unusual presentation of the disease, which was diagnosed only microbiologically. Chronic tropical ulcers therefore demand special microbiological attention.

[Examination of young women with recurrent symptoms of cystitis]

Fifty women with recurrent symptoms of cystitis (urgent onset of painful and frequent voiding) were extensively examined bacteriologically. All were submitted to intravenous urography, cystoscopy, gynaecological and urodynamic examination and the urine was examined cytologically and by culture. A control group of 10 healthy women were submitted to the same bacteriologic examinations. Only in a few cases did the investigations give an explanation of the condition but, generally, the examination programme did not contribute to the etiology. Chlamydia trachomatis was found in 6%, which was comparable to the normal population. Gardnerella vaginalis must be considered as part of the normal flora. The extensive examination programme cannot be recommended as a routine.

The clinical significance of the genital microbiologic flora at vacuum aspiration following miscarriage

85 women undergoing vacuum aspiration following miscarriage were studied. At the time of vacuum aspiration, immunofluorescent stainings for detection of C. trachomatis proved positive in 5.9% of the patients. Group B streptococci were isolated in 7.5%, coliforms in 3.5%, and Gardnerella vaginalis in 51% of the patients. The overall frequency of postabortal pelvic inflammatory disease (PID) was 3.5%, whereas 40% of chlamydia-positive women contracted postabortal PID (p less than 0.05). No significant relation between other microorganisms and postabortal PID was observed. The duration of postabortal bleeding was unrelated to the genital microbiologic flora. Based on anamnestic information about previous pregnancies and duration of preoperative bleeding it was possible to define subgroups at risk of harboring C. trachomatis and coliforms. The clinical significance of this is unknown.

Contamination of intravenous infusion systems--the effect of changing administration sets

Intravenous administration sets were changed at varying time intervals between every 24 h and 120 h in 387 patients. The rates of intraluminal contamination of the cannulae and of local inflammation were measured in relation to the time interval between changing sets. There was no correlation between phlebitis and intraluminal contamination, but a significant association was found between phlebitis and fever, infusion of potassium at greater than 10 mmol l-1, Venflon type 140 and infusion of blood or intralipid. No correlation was found between septicaemia and intraluminal contamination of the infusion systems. Contamination of cannulae increased slightly with time, but this was not statistically significant. We conclude that there will be no clinical benefit by daily changing of administration sets, compared with changing up to every fifth day.

Susceptibility testing with disc diffusion for new cephalosporins: pre-diffusion revisited

The purpose of the present study was to investigate the effect of 20-hour pre-diffusion, i.e. placing the antibiotic-containing discs on the agar for 20 hours prior to inoculation, as compared to direct diffusion, i.e. placing the discs on the agar immediately after inoculation, for the newer 3. generation cephalosporins as represented by ceftazidime and ceftriaxone. Regression lines (zone sizes vs. inhibitory concentrations, as measured by plate-dilution) were constructed for three groups of bacteria chosen because of their differences in growth characteristics on agar: E. coli (n = 50), Enterobacter sp. (n = 35), and streptococci (n = 51). The results for both cephalosporins were: 20-hour pre-diffusion produced larger zones than direct diffusion, regression studies for 20-hour pre-diffusion as compared to direct diffusion resulted in greater variation in zone sizes, numerically lower slopes, lower residual variances and higher correlation coefficients, and regression lines were significantly different for the 3 groups of bacteria with direct diffusion but not so with 20-hour pre-diffusion. Considering the interpretation of zone sizes with disc diffusion for the cephalosporins tested, 20-hour pre-diffusion was superior to direct diffusion.

Meningitis and brain abscess due to Haemophilus paraphrophilus

A case of meningitis and brain abscess due to Haemophilus paraphrophilus in a patient with congenital heart disease is reported. The abscess communicated with the cerebral ventricular system. Although the infecting strain was found to be highly sensitive to ampicillin, the patient died despite appropriate antimicrobial therapy. Characteristics distinguishing Haemophilus paraphrophilus and related species are discussed.

Antibacterial activity in vitro and regression studies for ceftazidime and ceftriaxone

The antibacterial activity in vitro of ceftazidime and ceftriaxone was investigated against 575 recent clinical isolates. Both cephalosporins displayed excellent activity against most of the pathogens tested, in particular Gram-negative bacteria, including Pseudomonas aeruginosa. Apart from the Pseudomonas group, Acinetobacter calcoaceticus and Campylobacter jejuni ceftriaxone was slightly to moderately more active than ceftazidime overall. Ceftriaxone was moderately active against Streptococcus faecalis. Regression lines for the two antibiotics were almost identical. Corresponding to differences in susceptibility, the zone sizes differed for the two drugs with respect to certain bacterial groups, e.g. Pseudomonas sp. and enterococci. Therefore, the two cephalosporins cannot substitute for each other in disc susceptibility testing. Breakpoints for disc tests around 8-16 micrograms/ml, as suggested in the literature, appear too high considering the beneficial pharmacokinetic properties of the two drugs.

Contamination of urological wounds by aerobic bacteria. Transvesical prostatectomy used as a model

The density of aerobic bacteria in the subcutaneous wound was quantified by the velvet pad rinse technique before (first stage) and after (second stage) opening of the bladder in 13 patients undergoing transvesical prostatectomy. Six patients had bacteria in the urine preoperatively (group A) and the same bacteria were isolated from bladder puncture during the operation and during second stage. Seven patients (group B) had sterile urine preoperatively and the bacteria isolated during first and second stage were commensals of the skin and the upper-respiratory tract. The bacterial density in group B was median 3.1 viable counts (v.c.) x 10(-1)/cm2 during first stage rising to median 4.7 v.c. x 10-1/cm2 during second stage, while group A showed an increase from median 4.3 v.c. x 10(-1)/cm2 during first stage to median 169,5 v.c. x 10(-1)/cm2 during second stage. The results of the study indicate the possibility of using selective antibiotic prophylaxis, with the relevant antibiotic for the bacteria isolated in the urine preoperatively, to reduce postoperative wound infection in urological surgery with opening of the urinary bladder.