Biomedical subjects

Pentti Huovinen

Publications and source records attributed to Pentti Huovinen.

At least 19 recordsLinked to original sources

PubMed2007

Identification of alpha-hemolytic streptococci by pyrosequencing the 16S rRNA gene and by use of VITEK 2.

Alpha-hemolytic streptococci are very difficult to identify by phenotypic methods. In this study, a pyrosequencing method for the identification of streptococcal species based on two variable regions of the 16S rRNA gene is described. Almost all studied streptococcal species (n = 51) represented by their type strains could be differentiated except for some closely related species of the Streptococcus bovis or S. salivarius group. The pyrosequencing results of alpha-hemolytic streptococci isolated from blood (n = 99) or from the normal pharyngeal microbiota (n = 25) were compared to the results obtained by the VITEK 2 with GP card (bioMérieux, Marcy l'Etoile, France). As expected, the results of the two methods did not completely agree, but 93 (75.0%) of the isolates assigned to the same streptococcal group by both methods and 57 (46.0%) reached consistent results at the species level. However, 10 strains remained unidentified by VITEK 2, and 4 isolates could not be assigned to any streptococcal group by pyrosequencing. Identification of members of the S. mitis and S. sanguinis groups proved difficult for both methods. Furthermore, the pyrosequencing analysis revealed great sequence variation, since only 43 (32.3%) of the 133 isolates analyzed by pyrosequencing had sequences identical to a type strain. The variation was greatest in the pharyngeal isolates, slightly lower in the blood culture isolates, and nonexistent in invasive pneumococcal isolates (n = 17) that all had the S. pneumoniae type strain sequence. The resolution of the results obtained by the two methods is impeded by the lack of a proper gold standard.

Bacterial Typing Techniques↗

PubMed2006

Macrolide and azithromycin use are linked to increased macrolide resistance in Streptococcus pneumoniae.

The connection between regional rates of antimicrobial resistance in Streptococcus pneumoniae and regional antimicrobial use in Finland was investigated. During the 6-year study period of 1997 to 2002, a total of 31,609 S. pneumoniae isolates were tested for penicillin resistance and a total of 23,769 isolates were tested for macrolide resistance in 18 central hospital districts in Finland. The regional macrolide resistance rates were compared with the local use of (i) all macrolides pooled and (ii) azithromycin. The penicillin resistance levels were compared with the consumption data for (i) penicillins, (ii) cephalosporins, (iii) all beta-lactams pooled, and (iv) all macrolides pooled. A statistically significant association between macrolide resistance and total use of macrolides and the use of azithromycin was found. Moreover, total use of beta-lactams and total use of cephalosporins were significantly connected to low-level penicillin resistance. A statistically significant association between penicillin-nonsusceptible isolates and penicillin or total macrolide consumption was not found. In conclusion, total macrolide use and azithromycin use are associated with increased macrolide resistance, and beta-lactam use and cephalosporin use are connected to increased low-level penicillin resistance in S. pneumoniae. Unnecessary prescribing of macrolides and cephalosporins should be avoided.

Anti-Bacterial Agents↗

PubMed2006

The Antimicrobial Treatment Strategies (MIKSTRA) program: a 5-year follow-up of infection-specific antibiotic use in primary health care and the effect of implementation of treatment guidelines.

BACKGROUND: A national 5-year follow-up study of infection-specific antibiotic use in primary care was conducted to see if prescribing practices change after implementing new treatment guidelines. METHODS: The data were collected during 1 week of November each year from 1998 to 2002 from 30 health care centers that covered a total population of 819,777 persons and in 2002 from 20 control health care centers that covered a population of 545,098 persons. National guidelines for 6 major infections (otitis media, sinusitis, throat infection, acute bronchitis, urinary tract infection, and bacterial skin infection) were published in 1999-2000. Multifaceted interventions were performed by local trainers teaching his or her coworkers, supported by feedback and patient and public information. RESULTS: The 6 infections targeted for intervention, together with unspecified upper respiratory tract infection constituted 80%-85% of all infections. The proportion of patients who received prescriptions for antibiotics did not change significantly. However, use of first-line antibiotics increased for all infections, and the change was significant for sinusitis (P<.001), acute bronchitis (P=.015), and urinary tract infections (P=.009). Also, the percentage of antibiotic treatments prescribed for the recommended duration increased significantly. Correct prescribing for respiratory tract infections improved by 6.4 percentage units (P<.001). However, there was no statistically significant difference in performance between study and control health care centers at follow-up. CONCLUSIONS: Moderate qualitative improvements in antibiotic use were observed after multifaceted intervention, but prescribing for unjustified indications, mainly acute bronchitis, did not decrease. Obtained infection-specific information on management of patients with infections in primary health care is an important basis for planning targeted interventions in the future.

Adolescent↗

PubMed2006

Reduction in fluoroquinolone susceptibility among non-typhoidal strains of Salmonella enterica isolated from Finnish patients.

OBJECTIVES: The proportion of Salmonella isolates with reduced susceptibility to fluoroquinolones has increased during recent years in many countries, especially in South-east Asia. The present study was performed to evaluate the incidence of and changes in quinolone resistance in Salmonella isolates of either foreign or domestic origin in Finland. METHODS: A total of 1004 Salmonella isolates collected from Finnish patients between 2000 and 2004 were analysed for ciprofloxacin susceptibility. Of these isolates, 504 were of domestic origin and 500 were of foreign origin, collected from travellers to 43 different countries. The Salmonella collection consisted of 89 different serotypes. All isolates belonged to non-typhoidal Salmonella enterica. RESULTS: Of all isolates, 3 (0.3%) were ciprofloxacin-resistant (MIC > or = 4 mg/L) and 214 (21.3%) exhibited reduced susceptibility to ciprofloxacin (MIC > or = 0.125-2 mg/L). The annual proportion of reduced susceptibility varied between 3 and 15% among the domestic Salmonella isolates (P = 0.123). Between 2000 and 2004, the annual proportion of reduced susceptibility increased significantly (from 23 to 39%; P = 0.001) among all foreign isolates as well as among those from Spain alone (from 4 to 73%; P < 0.001). Among the isolates from Thailand, reduced ciprofloxacin susceptibility remained at a constantly high level (52-66%) throughout the study. CONCLUSIONS: Our results show that reduced fluoroquinolone susceptibility in S. enterica is not restricted to South-east Asia alone but continues to grow rapidly in many parts of the world including countries of the European Union.

Anti-Bacterial Agents↗

PubMed2006

Relatedness of Escherichia coli strains with different susceptibility patterns isolated from beagle dogs during ampicillin treatment.

The aim of this study was to investigate the effects of ampicillin treatment on selection and diversity of ampicillin-resistant intestinal Escherichia coli in beagles treated with ampicillin, ampicillin + beta-lactamase (targeted to degrade antibiotic residues in the gut) or placebo. Selected faecal (n = 339) and jejunal (n = 63) E. coli isolates with known resistance patterns were typed using pulsed-field gel electrophoresis (PFGE). Among the 25 detected PFGE types, ampicillin resistance was detected in 6, none of which was dominant over others among the dogs. The resistant types increased especially in the ampicillin group, whilst beta-lactamase inhibited their emergence. Selection of genetically unrelated resistant strains rather than emerging resistance among previously susceptible strains accounts for increasing resistance rates during ampicillin treatment.

Ampicillin↗

PubMed2006

Cost-effectiveness of implementing national guidelines in the treatment of acute otitis media in children.

OBJECTIVES: Acute otitis media (AOM) is one of the most common diseases of childhood, representing a major disease burden on the society. New evidence-based guidelines for AOM, focusing on children under 7 years of age, were introduced in Finland in 1999. The aim of this study was to evaluate the cost-effectiveness of implementing those guidelines in Finland. METHODS: A 5-year prospective trial was conducted in thirty community primary healthcare centers in Finland. All AOM patients between 0 and 6 years of age visiting the study health centers for the first time, for this episode of illness, during 1 week in November 1998 (n = 579) and November 2002 (n = 369) were included in this study. The outcome measure was the percentage of symptom-free patients. RESULTS: The mean direct cost of an AOM episode per patient stayed almost the same after implementing the guidelines, euro152 in 1998 and euro150 in 2002. After implementing the guidelines, the percentage of symptom-free patients was 10 percentage points higher than before the guidelines. The treatment after the implementation of the guidelines, thus, was a dominant strategy. CONCLUSIONS: Implementing the guidelines to the treatment of AOM in children was associated with extra health benefits at slightly lower direct costs and, thus, is a dominant strategy. The focus of this study was on the short-term effects of the treatment; including long-term effects in the analysis might affect the results.

Acute Disease↗

PubMed2006

Management of pain in acute otitis media in Finnish primary care.

Most treatment recommendations for acute otitis media favour active use of pain relief medication. These data comprised 3059 Finnish primary care acute otitis media patients. We found that 10.4% of the patients were prescribed or recommended analgesics, which is in contrast to treatment recommendations.

Acute Disease↗

PubMed2005

In vitro activities of 11 fluoroquinolones against 226 Campylobacter jejuni strains isolated from Finnish patients, with special reference to ciprofloxacin resistance.

OBJECTIVES: Although Campylobacter jejuni is naturally susceptible to fluoroquinolones, the resistance to these antimicrobials has increased rapidly during the recent years. The aim of this study was to compare the activities of various older and newer fluoroquinolones towards C. jejuni, with special attention on ciprofloxacin-resistant strains. METHODS: We analysed the in vitro activities of 11 fluoroquinolones against 226 C. jejuni strains collected from Finnish patients between 1995 and 2000. RESULTS: Of all 226 C. jejuni strains, 134 (59.3%) were resistant to ciprofloxacin (MIC > or = 4 mg/L), 1 (0.4%) was intermediately resistant (MIC = 2 mg/L) and 91 (40.3%) were ciprofloxacin-susceptible (MIC < or = 1 mg/L). The MIC50 and MIC90 values of ciprofloxacin for the 91 ciprofloxacin-susceptible strains were 0.25 and 0.5 mg/L, respectively. The corresponding MIC50 and MIC90 values of levofloxacin were 0.25 and 0.5 mg/L, and those of moxifloxacin were 0.125 and 0.25 mg/L, these being lower than those of norfloxacin and ofloxacin. The two newer fluoroquinolones, sitafloxacin and clinafloxacin, exhibited the lowest MIC50 and MIC90 values: 0.016 and 0.064 mg/L of sitafloxacin and 0.032 and 0.125 mg/L of clinafloxacin, respectively. Sitafloxacin and clinafloxacin exhibited the lowest MIC50 and MIC90 values also for the 134 ciprofloxacin-resistant C. jejuni strains: 0.25 and 1 mg/L of sitafloxacin and 1 and 4 mg/L of clinafloxacin, respectively. CONCLUSIONS: Of the newer fluoroquinolones presently under development, sitafloxacin is in vitro highly effective towards C. jejuni, with low MIC values also for the ciprofloxacin-resistant strains. Sitafloxacin might be a candidate for clinical trials on campylobacteriosis.

Anti-Bacterial Agents↗

PubMed2005

In vitro activities of 11 fluoroquinolones against 816 non-typhoidal strains of Salmonella enterica isolated from Finnish patients with special reference to reduced ciprofloxacin susceptibility.

BACKGROUND: The number of Salmonella strains with reduced susceptibility to fluoroquinolones has increased during recent years in many countries, threatening the value of this antimicrobial group in the treatment of severe salmonella infections. METHODS: We analyzed the in vitro activities of ciprofloxacin and 10 additional fluoroquinolones against 816 Salmonella strains collected from Finnish patients between 1995 and 2003. Special attention was focused on the efficacy of newer fluoroquinolones against the Salmonella strains with reduced ciprofloxacin susceptibility. RESULTS: The isolates represented 119 different serotypes. Of all 816 Salmonella strains, 3 (0.4%) were resistant to ciprofloxacin (MIC > or = 4 microg/ml), 232 (28.4%) showed reduced susceptibility to ciprofloxacin (MIC > or = 0.125-2 microg/ml), and 581 (71.2%) were ciprofloxacin-susceptible. The MIC50 and MIC90 values of ciprofloxacin for these strains were 0.032 and 0.25 microg/ml, respectively, being lower than those of the other fluoroquinolone compounds presently on market in Finland (ofloxacin, norfloxacin, levofloxacin, and moxifloxacin). For two newer quinolones, clinafloxacin and sitafloxacin, the MIC50 and MIC90 values were lowest, both 0.016 and 0.064 microg/ml, respectively. Moreover, clinafloxacin and sitafloxacin exhibited the lowest MIC50 and MIC90 values, 0.064 and 0.125 microg/ml, against the 235 Salmonella strains with reduced susceptibility and strains fully resistant to ciprofloxacin. CONCLUSION: Among the registered fluoroquinolones in Finland, ciprofloxacin still appears to be the most effective drug for the treatment salmonella infections. Among the newer preparations, both clinafloxacin and sitafloxacin are promising based on in vitro studies, especially for strains showing reduced ciprofloxacin susceptibility. Their efficacy, however, has not been demonstrated in clinical investigations.

Anti-Infective Agents↗

PubMed2005

Mathematical model--tell us the future!

Studying bacterial resistance has direct importance for the antimicrobial treatment of individual patients. In addition, surveillance data pooled from individual diagnostic reports help physicians to choose the most effective drug for empirical therapy. However, this is not the limit of what can be done with the resistance data. There is an increasing need to synthesize the available strands of data in order to construct mathematical models that can be used as tools to predict the likely outcomes of various antibiotic policy options.

Anti-Bacterial Agents↗

PubMed2005

Prescription rates and diagnostic patterns are stable: a comparison of high-, medium- and low-prescribing primary care physicians treating community-acquired respiratory tract infections.

The objective was to study prescription practices of primary care physicians in prescribing antibiotics for community-acquired respiratory tract infections. Design was time series analysis and cross-sectional survey. The setting was 30 community primary health care centres. A case report form was completed for 3478 patient consultations treated by 198 office-based primary care physicians. Main outcome measures were: classification of diagnoses of respiratory tract infections made by each physician; number of antibiotic prescriptions related to these diagnoses; each physician's mean weekly number of antibiotic prescriptions during 6 months before and after the survey. Patients' risk (odds ratio: OR) to receive an antibiotic prescription from the high and medium prescribers was 5.81 (95% confidence interval [CI] 4.85-6.96) and 2.41 (95% CI 2.04-2.86), compared to low prescribers. High and medium prescribers made more diagnoses of otitis media (OR 2.07, 95% CI 1.70-2.53 and 1.85, 95% CI 1.51-2.26, respectively) and fewer diagnoses of unspecified upper respiratory tract infection (OR 0.32, 95% CI 0.26-0.38 and 0.57, 95% CI 0.48-0.68, respectively) than low prescribers. The rank of the prescription rate of high, medium and low prescriber groups remained the same for all diagnoses except pneumonia. In addition, the annual rank between high, medium and low prescriber groups remained stable; high group prescribed more antibiotics during the year than medium group, which prescribed more than low prescriber group.

Anti-Bacterial Agents↗

PubMed2005

Detection and quantification of macrolide resistance mutations at positions 2058 and 2059 of the 23S rRNA gene by pyrosequencing.

A pyrosequencing method for detection and quantification of macrolide resistance mutations at positions 2058 and 2059 (Escherichia coli numbering) of the 23S rRNA gene is described. The method was developed and tested for Streptococcus pneumoniae, Streptococcus pyogenes, Mycobacterium avium, Campylobacter jejuni, and Haemophilus influenzae.

Anti-Bacterial Agents↗

PubMed2005

Comparison between cultured small-intestinal and fecal microbiotas in beagle dogs.

The microbiota of the small intestine is poorly known because of difficulties in sampling. In this study, we examined whether the organisms cultured from the jejunum and feces resemble each other. Small-intestinal fluid samples were collected from 22 beagle dogs with a permanent jejunal fistula in parallel with fecal samples. In addition, corresponding samples from seven of the dogs were collected during a 4-week period (days 4, 10, 14, and 28) to examine the stability of the microbiota. In the jejunal samples, aerobic/facultative and anaerobic bacteria were equally represented, whereas anaerobes dominated in the fecal samples. Despite lower numbers of bacteria in the jejunum (range, 10(2) to 10(6) CFU/g) than in feces (range, 10(8) to 10(11) CFU/g), some microbial groups were more prevalent in the small intestine: staphylococci, 64% versus 36%; nonfermentative gram-negative rods, 27% versus 9%; and yeasts, 27% versus 5%, respectively. In contrast, part of the fecal dominant microbiota (bile-resistant Bacteroides spp., Clostridium hiranonis-like organisms, and lactobacilli) was practically absent in the jejunum. Many species were seldom isolated simultaneously from both sample types, regardless of their overall prevalence. In conclusion, the small intestine contains a few bacterial species at a time with vastly fluctuating counts, opposite to the results obtained for the colon, where the major bacterial groups remain relatively constant over time. Qualitative and quantitative differences between the corresponding jejunal and fecal samples indicate the inability of fecal samples to represent the microbiotas present in the upper gut.

Animals↗

PubMed2005

New quinolone resistance phenomenon in Salmonella enterica: nalidixic acid-susceptible isolates with reduced fluoroquinolone susceptibility.

We describe the emergence of a new quinolone resistance pattern in Salmonella enterica isolates from Southeast Asia. These isolates are susceptible to nalidixic acid but exhibit reduced susceptibility to ciprofloxacin. The increase of such strains may threaten the value of the nalidixic acid disk test to screen for reduced fluoroquinolone susceptibility in salmonellas.

Anti-Infective Agents↗

PubMed2005

Acute sinusitis: Finnish clinical practice guidelines.

These clinical practice guidelines aim at providing assistance mainly to primary health care physicians for the diagnosis and management of acute sinusitis. Despite the huge impact of upper respiratory infections, criteria for diagnoses are often vague, and physicians are often uncertain of their diagnoses. This is not surprising, as the sole definition of acute sinusitis is somewhat confusing, not to mention the existing discrepancies between treatments, even among specialists. The Finnish Society of Otorhinolaryngology has set up a committee to evaluate existing data on acute sinusitis and to formulate these guidelines. The committee comprised Finnish experts in adult and paediatric otorhinolaryngology, clinical microbiology, radiology, paediatrics, and epidemiology. Recommendations given are based on the principles of evidence-based medicine, with the level of evidence presented.

Acute Disease↗

PubMed2004

Mutation at the position 2058 of the 23S rRNA as a cause of macrolide resistance in Streptococcus pyogenes.

BACKGROUND: In streptococci, three macrolide resistance determinants (erm(B), erm(TR) and mef(A)) have been found. In addition, certain mutations at the ribosomal 23S RNA can cause resistance to macrolides. Mutation at the position 2058 of the 23S rRNA of the Streptococcus pyogenes as a cause of macrolide resistance has not been described before. METHODS: Antibiotic resistance determinations for the clinical S. pyogenes strain ni4277 were done using the agar dilution technique. Macrolide resistance mechanisms were studied by PCR and sequencing. All six rRNA operons were amplified using operon-specific PCR. The PCR products were partially sequenced in order to resolve the sequences of different 23S rRNA genes. RESULTS: One clinical isolate of S. pyogenes carrying an adenine to guanine mutation at the position 2058 of the 23S rRNA in five of the six possible rRNA genes but having no other known macrolide resistance determinants is described. The strain was highly resistant to macrolides and azalides, having erythromycin and azithromycin MICs > 256 microgram/ml. It was resistant to lincosamides (clindamycin MIC 16 microgram/ml) and also MIC values for ketolides were clearly elevated. The MIC for telithromycin was 16 microgram/ml. CONCLUSION: In this clinical S. pyogenes strain, a mutation at the position 2058 was detected. No other macrolide resistance-causing determinants were detected. This mutation is known to cause macrolide resistance in other bacteria. We can conclude that this mutation was the most probable cause of macrolide, lincosamide and ketolide resistance in this strain.

Journal Article↗

PubMed2004

Effect of macrolide consumption on erythromycin resistance in Streptococcus pyogenes in Finland in 1997-2001.

The aim of this study was to investigate the association between regional macrolide resistance in Streptococcus pyogenes and macrolide use in Finland. During 1997-2001, a total of 50,875 S. pyogenes isolates were tested for erythromycin susceptibility in clinical microbiology laboratories throughout Finland. The local erythromycin resistance levels were compared with the regional consumption data of all macrolides pooled and, separately, with the use of azithromycin. The regional resistance rates of 1 year were compared with the regional consumption of the previous year and with the average rates of use for the 2 previous years. A linear mixed model for repeated measures was used in modeling the association. A statistically significant association existed between regional erythromycin resistance in S. pyogenes and consumption of macrolides; association with azithromycin use alone was not found.

Drug Prescriptions↗

PubMed2004

Disc diffusion susceptibility testing of Haemophilus influenzae by NCCLS methodology using low-strength ampicillin and co-amoxiclav discs.

OBJECTIVES: The objective of this multicentre study was to define the accuracy and reproducibility of the NCCLS disc diffusion method for Haemophilus influenzae against ampicillin and co-amoxiclav in Finnish clinical microbiology laboratories. Special attention was paid to the ability of the laboratories to detect beta-lactamase-negative ampicillin-resistant (BLNAR) strains. METHODS: Three BLNAR and two beta-lactamase-negative ampicillin-susceptible isolates (BLNAS)-originating from the American Type Culture Collection (ATCC) and UK National External Quality Assessment (UKNEQAS) schemes-were included in this study. Susceptibility tests for these isolates were performed in 26 clinical microbiology laboratories, in accordance with NCCLS guidelines. Additionally, low-strength discs for ampicillin (2 microg) and co-amoxiclav (3 microg) were tested. RESULTS: The low-strength discs for ampicillin and co-amoxiclav categorized more accurately BLNAR and BLNAS H. influenzae isolates than did the high-strength discs recommended by the NCCLS. In addition, the high-strength discs produced more major errors than the low-strength discs (22 versus six for ampicillin and 40 versus seven for co-amoxiclav). Great variation occurred in the method regardless of the antibiotic concentration of the discs. CONCLUSIONS: The use of low-content ampicillin and co-amoxiclav discs is recommended for the susceptibility testing of H. influenzae. Interpretative criteria of S > or = 17 mm and R < or = 13 mm for both discs are suggested.

Amoxicillin-Potassium Clavulanate Combination↗