Susceptibility Of Respiratory Tract Pathogens Research Articles

Susceptibility to ceftobiprole of respiratory-tract pathogens collected in the United Kingdom and Ireland during 2014-2015.

PurposeLower respiratory tract infections (LRTIs) can cause significant morbidity and mortality and are becoming increasingly difficult to treat because of the growing prevalence of resistance to conventional antimicrobial agents. This study aimed to assess the current in vitro susceptibility of respiratory tract pathogens collected from the UK and Ireland to ceftobiprole, an advanced-generation cephalosporin, as compared with other antibiotics.MethodsPathogens isolated from patients with LRTIs were analyzed as part of the British Society for Antimicrobial Chemotherapy Antimicrobial Resistance Surveillance Programme during 2014–2015. Antibiotic susceptibility was evaluated using European Committee on Antimicrobial Susceptibility Testing breakpoints, including the ceftobiprole pharmacokinetic/pharmacodynamic non-species-specific breakpoint when species-specific breakpoints were not available.ResultsOne thousand one hundred and sixty-eight isolates from community-onset LRTIs and 1,264 isolates from hospital-onset LRTIs were analyzed. The ceftobiprole susceptibility rate was 99.8% (428/429) for Streptococcus pneumoniae, 100% (502/502) for Haemophilus influenzae, and 99.6% (236/237) for Moraxella catarrhalis. All Staphylococcus aureus isolates, including methicillin-susceptible S. aureus (MSSA; N=181) and methicillin-resistant S. aureus (MRSA; N=35), were susceptible to ceftobiprole. Overall, ceftobiprole susceptibility was observed in 88.1% (215/244) of Escherichia coli isolates, 83.4% (156/187) of Klebsiella pneumoniae isolates and 86.7% (98/113) of Enterobacter spp. isolates.ConclusionCeftobiprole had in vitro activity against all S. aureus (both MSSA and MRSA) isolates, and almost all S. pneumoniae isolates, as well as against Gram-negative bacteria associated with community-onset or hospital-onset LRTIs. Based on this analysis, ceftobiprole is a good treatment option when broad-spectrum antibiotic coverage is needed for LRTIs.

Monitoring of antimicrobial susceptibility of respiratory tract pathogens isolated from diseased cattle and pigs across Europe, 2009–2012: VetPath results

VetPath is an ongoing pan-European antibiotic susceptibility monitoring programme that collects pathogens from diseased cattle, pigs and poultry. In the current study, 996 isolates from cattle and pig respiratory tract infections were tested for their antimicrobial susceptibilities. Non-replicate lung samples or nasopharyngeal/nasal swabs were collected from animals with acute clinical signs in 10 countries during 2009–2012. Pasteurella multocida, Mannheimia haemolytica and Histophilus somni from cattle and P. multocida, Actinobacillus pleuropneumoniae, Haemophilus parasuis, Bordetella bronchiseptica and Streptococcus suis from pigs were isolated by standard methods. S. suis was also isolated from meningitis cases. MIC values of 16 or 17 antibiotics were assessed centrally by broth microdilution following CLSI standards. Results were interpreted using CLSI breakpoints where available. Cattle isolates were generally highly susceptible to most antibiotics, except to tetracycline (3.0–12.0% resistance). Low levels of resistance (0–4.0%) were observed for the macrolide antibiotics. Resistance to spectinomycin varied from 0 to 6.0%. In pig isolates similar observations were made. Resistance to amoxicillin/clavulanic acid, ceftiofur, enrofloxacin, florfenicol, tulathromycin, tiamulin and tilmicosin was absent or <2%. Trimethoprim/sulfamethoxazole resistance varied from 1.9 to 5.3%, but tetracycline resistance varied from 20.4% in P. multocida to 88.1% in S. suis. For most antibiotics and pathogens the percentage resistance remained unchanged or only increased numerically as compared to that of the period 2002–2006. In conclusion, absence or low resistance to antibiotics with defined clinical breakpoints, except for tetracycline, was observed among the major respiratory tract pathogens recovered from livestock. Comparison of all antibiotics and organisms was hampered since for almost half of the antibiotics no CLSI-defined breakpoints were available.

Antimicrobial Susceptibility of Respiratory Tract Pathogens in Japan During PROTEKT Years 1–5 (1999–2004)

Susceptibility to a range of antimicrobial agents was determined among isolates of Streptococcus pneumoniae, Streptococcus pyogenes, and Haemophilus influenzae collected in 12 centers throughout Japan during years 1-5 (the respiratory seasons of 1999-2004) of the longitudinal Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin study. The most frequent source of isolates of S. pneumoniae was from patients with community-acquired pneumonia (CAP) (25.3%). Reduced susceptibility to penicillin or erythromycin resistance was common among S. pneumoniae isolates (30.9-44.5% and 77.2-81.9%, respectively). The macrolide MIC(50) for S. pneumoniae was >or=128 microg/ml (azithromycin and erythromycin) and >or=64 microg/ml (clarithromycin). The erm(B) genotype accounted for the most erythromycin-resistant isolates in each study year. H. influenzae isolates were most commonly derived from patients with CAP (26.2%). The proportion of H. influenzae isolates that were beta-lactamase positive ranged between 4.3% and 9.7%. The prevalence of beta-lactamase-negative ampicillin-resistant isolates increased from 0.4% to 2.6% between years 1 and 4 then to 19.7% in year 5. S. pyogenes isolates were highly susceptible to most antimicrobial agents except macrolides and tetracycline. Telithromycin was highly active against all three pathogens examined throughout the study.

Antimicrobial susceptibility of respiratory tract pathogens in Japan during PROTEKT years 1–3 (1999–2002)

Data are presented on antimicrobial resistance among isolates of Streptococcus pneumoniae, Streptoco-ccus pyogenes, Haemophilus influenzae, and Moraxella catarrhalis collected in Japan during years 1-3 (1999-2002) of the Prospective Resistant Organism Tracking and Epidemiology for the Ketolide Telithromycin (PROTEKT) surveillance study. In addition to the standard panel of PROTEKT antimicrobial agents, eight other agents often used in Japan also were tested against these isolates. The majority (30%-55%) of S. pneumoniae and H. influenzae isolates were collected from patients with community-acquired pneumonia, whereas most (>70%) S. pyogenes isolates came from patients with tonsillitis/pharyngitis. Penicillin and macrolide resistance were high among isolates of S. pneumoniae, averaging 30.9%-44.5% and 77.2%-79.9%, respectively, across all centers over the 3 study years; the highest occurrences were reported among pediatric patients aged 0-2 years. The erm(B) genotype accounted for >50% of all erythromycin-resistant isolates each study year. S. pyogenes isolates were highly susceptible to most antimicrobial agents except the macrolides and tetracycline. beta-Lactamase production among H. influenzae isolates range was 8.5%-9.7% per annum. A total of 9 beta-lactamase-negative, ampicillin-resistant isolates were collected during the study. Almost all (>95%) M. catarrhalis isolates were beta-lactamase positive each year. Telithromycin was highly active against all pathogens examined in this study during all 3 years.

Trends in antibiotic resistance of respiratory tract pathogens in children in Geneva, Switzerland

Bacteria increasingly resistant to antibiotics are a major treatment concern of respiratory tract pathogens in children. The aim of this study was to assess the trends of resistance of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis to several classes of antibiotics in children<16 years of age and to compare its prevalence with surrounding countries. We studied retrospectively the susceptibility of respiratory tract pathogens isolated from specimens collected from patients at the Geneva Children's Hospital between 1989 and 2004. The susceptibility of S. pneumoniae to penicillin decreased from 98% to 58% (P<0.001) within 16 years, mainly due to strains intermediately resistant (MICs 0.12-1.0 microg/ml). Also erythromycin-susceptible pneumococci decreased from 97% to 63% (P<0.001). The susceptibility of H. influenzae to amoxicillin also significantly declined (87% vs. 82%, P<0.001), and the susceptibility of M. catarrhalis to this drug almost disappeared (29% vs. 5%, P<0.001). However, in 2004 these two bacteria remained 100% susceptible to amoxicillin-clavulanic acid, second and third generation cephalosporins. Invasive H. influenzae strains were significantly more resistant to ampicillin than non-invasive strains, but no susceptibility difference between invasive and non-invasive S. pneumoniae was determined. During the 16 years studied, the antibiotic resistance of respiratory tract pathogens steadily and significantly increased in children, especially S. pneumoniae. This situation in Geneva is similar to neighbouring France rather than to the rest of Switzerland. A permanent surveillance of microbial susceptibility to antibiotics is essential and a limitation of antibiotic prescription together with information of the judicious use may impede the actual resistance trend.

PROTEKT 1999–2000: a multicentre study of the antimicrobial susceptibility of respiratory tract pathogens in Japan

A six-centre study in Japan during the winter of 1999-2000 assessed the in vitro activity of >20 antimicrobial agents against the common respiratory pathogens Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, and Moraxella catarrhalis. The minimum inhibitory concentrations (MIC) of each antimicrobial was determined against these isolates using National Committee for Clinical Laboratory Standards (NCCLS) methodology. Among S. pneumoniae isolates, 44.5% were penicillin resistant. The macrolide resistance rate was 77.9% with 90.5% of penicillin-resistant strains also being macrolide resistant. Resistance mechanisms in macrolide-resistant isolates were identified as mef(A) or erm(B) in 42.5% and 52.5%, respectively. Of the fluoroquinolone-resistant isolates (1.3%), most were also penicillin and macrolide resistant. All strains were inhibited by telithromycin at <or=1mg/L. Among S. pyogenes isolates, erythromycin resistance was 17.5% overall but showed considerable variation among the six centres. For H. influenzae, 8.5% produced beta-lactamase and a single beta-lactamase-negative, ampicillin-resistant isolate (0.36%) was obtained, and there was no fluoroquinolone resistance. All isolates were susceptible to telithromycin. Most antimicrobials showed good activity against M. catarrhalis, although 96.7% were beta-lactamase positive. The prevalence of antimicrobial resistance to macrolides, penicillin and the fluoroquinolones among the common respiratory pathogens is high in Japan.

PROTEKT 1999–2000: a multicentre study of the antibiotic susceptibility of respiratory tract pathogens in Hong Kong, Japan and South Korea

A multicentre surveillance study performed in the Far East during 1999–2000 investigated the in vitro activity of >20 antibacterials against common respiratory pathogens. In Hong Kong, Japan, and South Korea, 57.1, 44.5 and 71.5% Streptococcus pneumoniae were penicillin-resistant and 71.4, 77.9 and 87.6% were erythromycin-resistant, respectively. Overall, >90% of penicillin-resistant strains were also macrolide-resistant. All strains were susceptible to telithromycin. Fluoroquinolone-resistant isolates in Japan (1.3%), Hong Kong (14.3%) and South Korea (2.9%) were mostly co-resistant to penicillin, macrolides and tetracycline. Beta-lactamase production by Haemophilus influenzae isolates was 8.5% in Japan, 17.1% in Hong Kong and 64.7% in strains from South Korea. A single (0.27%) BLNAR isolate was obtained in Japan. There was no fluoroquinolone resistance. Moraxella catarrhalis was inhibited by telithromycin at ≤0.5 mg/l and remained susceptible to macrolides, fluoroquinolones and amoxicillin-clavulanate. Resistance to antibacterials, particularly penicillin and macrolides, has reached high but stable levels in the Far East and the presence of multiply-resistant pneumococci is well established.

Surveillance of resistance in bacteria causing community‐acquired respiratory tract infections

Bacterial resistance to antibiotics in community-acquired respiratory tract infections is a serious problem and is increasing in prevalence world-wide at an alarming rate. Streptococcus pneumoniae, one of the main organisms implicated in respiratory tract infections, has developed multiple resistance mechanisms to combat the effects of most commonly used classes of antibiotics, particularly the beta-lactams (penicillin, aminopenicillins and cephalosporins) and macrolides. Furthermore, multidrug-resistant strains of S. pneumoniae have spread to all regions of the world, often via resistant genetic clones. A similar spread of resistance has been reported for other major respiratory tract pathogens, including Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pyogenes. To develop and support resistance control strategies it is imperative to obtain accurate data on the prevalence, geographic distribution and antibiotic susceptibility of respiratory tract pathogens and how this relates to antibiotic prescribing patterns. In recent years, significant progress has been made in developing longitudinal national and international surveillance programs to monitor antibiotic resistance, such that the prevalence of resistance and underlying trends over time are now well documented for most parts of Europe, and many parts of Asia and the Americas. However, resistance surveillance data from parts of the developing world (regions of Central America, Africa, Asia and Central/Eastern Europe) remain poor. The quantity and quality of surveillance data is very heterogeneous; thus there is a clear need to standardize or validate the data collection, analysis and interpretative criteria used across studies. If disseminated effectively these data can be used to guide empiric antibiotic therapy, and to support-and monitor the impact of-interventions on antibiotic resistance.

Antibiotic medication and bacterial resistance to antibiotics: a survey of children in a Vietnamese community.

To investigate antibiotic use and antibiotic susceptibility of respiratory tract pathogens in children aged 1-5 years in Bavi, Vietnam. Nasopharynx and throat specimens were collected from 200 children from randomly selected households in a demographically defined population. Respiratory isolates were tested for antibiotic susceptibility according to the standard disk diffusion method. A questionnaire survey of carers elicited information on type of antibiotic used, duration of treatment, where the antibiotics had been purchased, type of treatment information retained by carers and episodes of illness preceding the study. 82% of the children had at least one symptom of acute respiratory tract infection (ARI) in the 4 weeks prior to the study, and of these 91% were treated with antibiotics. The most commonly used antibiotics were ampicillin (74%), penicillin (12%), amoxicillin (11%), erythromycin (5%), tetracycline (4%) and streptomycin (2%). Ampicillin was used for 3.3 days on average (SD:1.8) and penicillin for 2.6 days (SD:0.7). When deciding which antibiotic to use, 67% of the carers consulted the pharmacy seller, 11% decided themselves and 22% followed the doctor's prescription. The carrier rate of Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis was 50%, 39% and 17%, respectively. Isolates from 145 children were susceptibility tested, and 74% were found to carry resistant pathogens. Of the tested isolates, 90% of S. pneumoniae, 68% of H. influenzae and 74% of M. catarrhalis were resistant to at least one antibiotic. The mean number of antibiotics (susceptible strains excluded) to which resistance was found was 2.0 (SD:1.2), 2.5 (SD:1.8) and 2.1 (SD:0.9), respectively. S. pneumoniae and H. influenzae showed high resistance to tetracycline (88% and 32%, respectively), trimethoprim/sulphonamide (32% and 44%), and chloramphenicol (25% and 24%). 23% of S. pneumoniae were erythromycin-resistant and 18% of H. influenzae isolates were resistant to ampicillin. There was a significant difference in ampicillin and penicillin resistance between the group of children previously treated with beta lactam antibiotics and the group of children who did not receive antibiotics. As reported by the carers, children in Bavi are treated with antibiotics frequently. Most antibiotics were obtained without consulting a doctor. High levels of antibiotic resistance and high prevalence of multidrug-resistant strains were found among respiratory pathogens. The existence of a large reservoir of resistance genes among children in low-income countries represents a threat to the success of antibiotic therapy throughout the world. Multi-faceted programmes to improve rational use of antibiotics in Vietnam are urgently needed.

Prevalence of potential respiratory disease bacteria in children in Ethiopia. Antimicrobial susceptibility of the pathogens and use of antibiotics among the children

Acute respiratory infections are primary causes of morbidity and mortality in children in developing countries. This project was designed to investigatc antimicrobial susceptibility of respiratory tract pathogens isolated from children in rural and city areas, and to contribute to the rational choice of antibiotics for respiratory tract infections in children in Ethiopia. Nasopharynx and throat cultures were taken from all children under five years of age in three study areas representing different levels of contact with health care and accessibility to modern drugs, such as antibiotics. In all, 1126 children were cultured. Huemophilus influence and Streptococcus pneumonicie were both found in 85–90% of the children, and beta‐haemolytic streptococci group A in 12%. The level of antimicrobial resistance was low. None of the 954 strains of H. irfluence were beta‐lactamase producers. Pneumococci were susceptible to penicillin. The use of antibiotics was also low; 11 of 1126 children had antibiotics on the day of culture or the day before. The choice of antibiotics was not limited by resistance, and emphasis could be put on low cost, minimizing adverse drug reactions and ecological impact.

Prevalence of potential respiratory disease bacteria in children in Ethiopia. Antimicrobial susceptibility of the pathogens and use of antibiotics among the children.

Acute respiratory infections are primary causes of morbidity and mortality in children in developing countries. This project was designed to investigate antimicrobial susceptibility of respiratory tract pathogens isolated from children in rural and city areas, and to contribute to the rational choice of antibiotics for respiratory tract infections in children in Ethiopia. Nasopharynx and throat cultures were taken from all children under five years of age in three study areas representing different levels of contact with health care and accessibility to modern drugs, such as antibiotics. In all, 1126 children were cultured. Haemophilus influenzae and Streptococcus pneumoniae were both found in 85-90% of the children, and beta-haemolytic streptococci group A in 12%. The level of antimicrobial resistance was low. None of the 954 strains of H. influenzae were beta-lactamase producers. Pneumococci were susceptible to penicillin. The use of antibiotics was also low; 11 of 1126 children had antibiotics on the day of culture or the day before. The choice of antibiotics was not limited by resistance, and emphasis could be put on low cost, minimizing adverse drug reactions and ecological impact.