MIC quality control guidelines for doxycycline when testing Gram-positive control strains by the reference methods

Prevalence of community-acquired respiratory tract infections associated with Q fever in Japan

Several new fluoroquinolones have been marketed since the late 1990s. Fluoroquinolones are an effective treatment for most community-acquired respiratory tract infections, including acute sinusitis, acute exacerbations of chronic bronchitis and community-acquired pneumonia. However, other antibiotics, including β-lactams, macrolides, tetracyclines and trimethoprim-sulfamethoxazole, are also effective against these respiratory infections. From a managed care perspective, it is the subtle differences between the drugs in the eradication of bacterial pathogens, adverse effects, dose regimens, compliance issues, bacterial resistance and cost that determine the best choice for the management of pneumonia, sinusitis or exacerbations of chronic bronchitis. The potential for bacterial resistance is perhaps the only significant barrier to extensive fluoroquinolone use in community-acquired respiratory tract infections. Cost-effectiveness must be balanced with quality care, both from an individual perspective and that of the greater society.

Antimicrobial activity of tigecycline tested against organisms causing community-acquired respiratory tract infection and nosocomial pneumonia

Frequency of pathogen occurrence and antimicrobial susceptibility among community-acquired respiratory tract infections in the respiratory surveillance program study: microbiology from the medical office practice environment

Background Community-acquired bacterial pneumonia (CABP) is a frequent cause of patient morbidity and mortality. Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis are frequent etiologic agents of CABP. Ceftaroline fosamil is a parenteral cephem approved treatment of patients with CABP caused by S. pneumoniae (including cases with concurrent bacteremia), methicillin-susceptible Staphylococcus aureus (MSSA), H. influenzae, and some species of Enterobacterales. In this study we report the in vitro activity of ceftaroline and comparators against isolates from community-acquired respiratory tract infections (CARTI) collected through a global surveillance program. Methods Clinically relevant, non-duplicate, isolates cultured from respiratory specimens by clinical laboratories in 54 countries in 2018-2021 were collected by the ATLAS Surveillance Program central laboratory (IHMA, Schaumburg, IL, USA). Community-acquired infections were defined as those from patients < 48 hours in hospital. In total, 7,886 isolates of S. pneumoniae, H. influenzae, M. catarrhalis, MSSA, and methicillin-resistant S. aureus (MRSA) were tested. The isolates (n/percent of total) originated from Asia/South Pacific (1,893/24.0%); Europe (4,283/54.3%); Latin America (671/8.5%); Middle East/Africa (659/8.4%); and North America (Canada only) (380/4.8%). Ceftaroline and comparator agent MICs were determined by CLSI M07 broth microdilution methodology. MICs were interpreted using 2023 CLSI M100 MIC breakpoints. Results The in vitro activity of ceftaroline and comparator agents is summarized in the table. Greater than 99% of S. pneumoniae and 100% of MSSA were susceptible to ceftaroline, including penicillin-nonsusceptible S. pneumoniae based on a dosage of 600 mg every 12h. Sixty-two (9.6%) MRSA were ceftaroline-susceptible-dose-dependent (MIC 2-4 µg/mL) based on a dosage of 600 mg every 8h administered over 2h, with the majority from (n) Thailand (9), S. Korea (7), and China (6). Four isolates, from S. Korea (2), China (1), and Ukraine (1) were resistant to CPT (MIC of ≥8 µg/mL). 99.6% of H. influenzae were susceptible to ceftaroline. Conclusion Ceftaroline demonstrated potent in vitro activity against current pathogens associated with CABP from a global collection. Disclosures Meredith Hackel, PhD, Pfizer Inc.: Honoraria|Venatorx: Paid fees for conducting the study and abstract preparation Gregory Stone, PhD, Pfizer: Stocks/Bonds Daniel F. Sahm, PhD, Merck & Co., Inc.: Honoraria|Pfizer Inc.: Honoraria|Venatorx: Paid fees for conducting the study and abstract preparation

The new respiratory fluoroquinolones (gatifloxacin, gemifloxacin, levofloxacin, moxifloxacin, and on the horizon, garenoxacin) offer many improved qualities over older agents such as ciprofloxacin. These include retaining excellent activity against Gram-negative bacilli, with improved Gram-positive activity (including Streptococcus pneumoniae and Staphylococcus aureus). In addition, gatifloxacin, moxifloxacin and garenoxacin all demonstrate increased anaerobic activity (including activity against Bacteroides fragilis). The new fluoroquinolones possess greater bioavailability and longer serum half-lives compared with ciprofloxacin. The new fluoroquinolones allow for once-daily administration, which may improve patient adherence. The high bioavailability allows for rapid step down from intravenous administration to oral therapy, minimizing unnecessary hospitalization, which may decrease costs and improve quality of life of patients. Clinical trials involving the treatment of community-acquired respiratory infections (acute exacerbations of chronic bronchitis, acute sinusitis, and community-acquired pneumonia) demonstrate high bacterial eradication rates and clinical cure rates. In the treatment of community-acquired respiratory tract infections, the various new fluoroquinolones appear to be comparable to each other, but may be more effective than macrolide or cephalosporin-based regimens. However, additional data are required before it can be emphatically stated that the new fluoroquinolones as a class are responsible for better outcomes than comparators in community-acquired respiratory infections. Gemifloxacin (except for higher rates of hypersensitivity), levofloxacin, and moxifloxacin have relatively mild adverse effects that are more or less comparable to ciprofloxacin. In our opinion, gatifloxacin should not be used, due to glucose alterations which may be serious. Although all new fluoroquinolones react with metal ion-containing drugs (antacids), other drug interactions are relatively mild compared with ciprofloxacin. The new fluoroquinolones gatifloxacin, gemifloxacin, levofloxacin, and moxifloxacin have much to offer in terms of bacterial eradication, including activity against resistant respiratory pathogens such as penicillin-resistant, macrolide-resistant, and multidrug-resistant S. pneumoniae. However, ciprofloxacin-resistant organisms, including ciprofloxacin-resistant S. pneumoniae, are becoming more prevalent, thus prudent use must be exercised when prescribing these valuable agents.

To investigate the levels of white blood cell count (WBC), procalcitonin (PCT), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) in patients with acute community-acquired lower respiratory tract infections and the value of their combined detection in predicting the occurrence of complications. A retrospective analysis was conducted on the clinical data of 218 patients with acute community-acquired lower respiratory tract infections admitted to Baoding No.1 Central Hospital from January 2021 to December 2021. All patients were divided into two groups according to the presence of complications during treatment: the group with complications (observation group) and the group without complications (control group). The treatment situation of the two groups was compared, and their levels of WBC, PCT, CRP and ESR were quantitatively detected and compared. Patients in the observation group were hospitalized for significantly longer days than those in the control group (P<0.05), and their combined pleural effusion percentage and oxygen uptake rate were higher than those in the control group (P<0.05). The levels of WBC, PCT, CRP and ESR in the observation group were significantly higher than those in the control group at admission, with statistically significant differences (P<0.05). Moreover, the positive rates of WBC, PCT, CRP and ESR in the observation group were higher than those in the control group in the single detection and the combined detection (P<0.05). The combined detection of WBC, PCT, CRP and ESR has substantial predictive value in predicting the occurrence of complications in patients with community-acquired lower respiratory tract infections.

Multicentre surveillance is essential in order to monitor the prevalence of certain resistance phenotypes and to identify rapidly the emergence of new ones. However, many surveillance studies are based either on a relatively small number of isolates from a single country, or on a large number of isolates from many different countries and so are not equally meaningful. Extensive national multicentre surveillance would provide a more reliable strategy for assessing the extent of antimicrobial resistance in individual countries. This article describes Spanish experience with the surveillance network SAUCE, and summarizes the main results on antimicrobial resistance in the three key bacterial pathogens involved in community-acquired respiratory tract infections in Spain: Streptococcus pneumoniae, Haemophilus influenzae and Streptococcus pyogenes.

Background: Local surveillance of antimicrobial resistance is essential to guide empirical treatment strategies for respiratory tract infections. Long-term local data are particularly important in the context of rising global resistance and regional variations in antimicrobial susceptibility patterns, enabling clinicians to make informed empirical therapy decisions. Objectives: This study aimed to determine and compare antimicrobial resistance rates in Streptococcus pneumoniae (n = 335) and Haemophilus influenzae (n = 185) isolates obtained from community-acquired respiratory tract infections at Hacettepe University Hospital between 2010 and 2023. Methods: Streptococcus pneumoniae and H. influenzae isolates (one isolate per patient) recovered from sputum, tracheal aspirate, or bronchoalveolar lavage samples of patients with community-acquired pneumonia were included in the SENTRY surveillance program. Antimicrobial susceptibilities were determined by the microdilution method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines (2025) using cation-adjusted Mueller–Hinton broth supplemented with lysed horse blood. Results: Penicillin non-susceptibility (I+R) was 67.2% in S. pneumoniae isolates (42.7% intermediate, 24.5% resistant), while ampicillin resistance in H. influenzae was 13.0%. All S. pneumoniae isolates remained fully susceptible to meropenem, linezolid, and vancomycin. Ceftaroline resistance rates were 1.5% in S. pneumoniae and 3.2% in H. influenzae. No resistance to ceftriaxone was detected among H. influenzae isolates. Conclusions: High rates of penicillin and macrolide non-susceptibility in S. pneumoniae limit the empirical use of these agents in our setting. In contrast, ceftriaxone and respiratory fluoroquinolones remain highly effective options for the empirical treatment of community-acquired respiratory tract infections. These findings underscore the importance of continuous local surveillance to support rational antimicrobial therapy.

Telithromycin new product overview

BackgroundAntimicrobial resistance (AMR) is one of the biggest threats to global public health. Selection of resistant bacteria is driven by inappropriate use of antibiotics, amongst other factors. COVID-19 may have exacerbated AMR due to unnecessary antibiotic prescribing. Country-level knowledge is needed to understand options for action.ObjectivesTo review the current situation with respect to AMR in Vietnam and initiatives addressing it. Identifying areas where more information is required will provide a call to action to minimize any further rises in AMR within Vietnam and improve patient outcomes.MethodsNational initiatives to address AMR in Vietnam, antibiotic use and prescribing, and availability of susceptibility data, in particular for the key community-acquired respiratory tract infection (CA-RTI) pathogens Streptococcus pneumoniae and Haemophilus influenzae, were identified. National and international antibiotic prescribing guidelines for CA-RTIs (community-acquired pneumonia, acute otitis media and acute bacterial rhinosinusitis) commonly used locally were also reviewed, plus local antibiotic availability. Insights from clinicians in Vietnam were sought to contextualize this information.ConclusionsIn Vietnam there have been some initiatives addressing AMR; Vietnam was the first country in the Western Pacific Region to develop a national action plan to combat AMR, which according to the WHO is being implemented. Vietnam also has one of the highest rates of AMR in Asia due, in part, to the overuse of antimicrobial drugs, both in the animal health sector and in humans in both hospitals and the community. In addition, despite a 2005 law requiring antibiotic prescription, there is unrestricted access to over-the-counter antibiotics. Several global surveillance studies provide antibiotic susceptibility data for CA-RTI pathogens in Vietnam including Survey of Antibiotic Resistance (SOAR) and SENTRY (small isolate numbers only). For management of the common CA-RTIs in Vietnam there are several country-specific local antibiotic prescribing guidelines and in addition, there is a range of international guidelines referred to, but these may have been created based on pathogen resistance patterns that might be very different to those in Vietnam. Expert clinician opinion confirms the high resistance rates among common respiratory pathogens. A more standardized inclusive approach in developing local guidelines, using up-to-date surveillance data of isolates from community-acquired infections in Vietnam, could make management guideline use more locally relevant for clinicians. This would pave the way for a higher level of appropriate antibiotic prescribing and improved adherence. This would, in turn, potentially limit AMR development and improve clinical outcomes for patients.

BackgroundAntimicrobial reistance (AMR) is one of the biggest threats to global public health. Selection of resistant bacteria is driven by inappropriate use of antibiotics, amongst other factors. COVID-19 may have exacerbated AMR due to unnecessary antibiotic prescribing. Country-level knowledge is needed to understand options for action.ObjectivesTo review AMR in Russia and any initiatives addressing it. Identifying any areas where more information is required will provide a call to action to minimize any further rise in AMR within Russia and to improve patient outcomes.MethodsNational AMR initiatives, antibiotic use and prescribing, and availability of susceptibility data, in particular for the key community-acquired respiratory tract infection (CA-RTI) pathogens Streptococcus pneumoniae and Haemophilus influenzae, were identified. National and international antibiotic prescribing guidelines commonly used locally for specific CA-RTIs (community-acquired pneumonia, acute otitis media and acute bacterial rhinosinusitis) were also reviewed, plus local antibiotic availability. Insights from both a local clinician and a local clinical microbiologist were sought to contextualize this information.ConclusionsRussia launched a national strategy in 2017 to prevent the spread of AMR and the WHO reports that as of 2020–21, it is being implemented and actively monitored. Reports suggest outpatient antibiotic use of antibiotics is high and that non-prescription access and self-medication are very common. Antibiotic susceptibility studies in Russia include PeHASus, a multicentre epidemiological study focusing on susceptibilities of community-acquired respiratory pathogens and international studies such as Survey of Antibiotic Resistance (SOAR), Antimicrobial Testing Leadership and Surveillance (ATLAS) and SENTRY Antimicrobial Surveillance Program. International guidelines are used to support the development of local guidelines in Russia, and for the common CA-RTIs Russian clinicians use of several country-specific local antibiotic prescribing guidelines. A standardized inclusive approach in developing local guidelines, using up-to-date surveillance data of isolates from community-acquired infections in Russia, could make guideline use more locally relevant for clinicians. This would pave the way for a higher level of appropriate antibiotic prescribing and improved adherence. This would, in turn, potentially limit AMR development and improve patient outcomes.

To determine the effect of amoxicillin treatment on resistance selection in patients with community-acquired lower respiratory tract infections in a randomized, placebo-controlled trial. Patients were prescribed amoxicillin 1 g, three times daily (n = 52) or placebo (n = 50) for 7 days. Oropharyngeal swabs obtained before, within 48 h post-treatment and at 28-35 days were assessed for proportions of amoxicillin-resistant (ARS; amoxicillin MIC ≥2 mg/L) and -non-susceptible (ANS; MIC ≥0.5 mg/L) streptococci. Alterations in amoxicillin MICs and in penicillin-binding-proteins were also investigated. ITT and PP analyses were conducted. ARS and ANS proportions increased 11- and 2.5-fold, respectively, within 48 h post-amoxicillin treatment compared with placebo [ARS mean increase (MI) 9.46, 95% CI 5.57-13.35; ANS MI 39.87, 95% CI 30.96-48.78; P < 0.0001 for both]. However, these differences were no longer significant at days 28-35 (ARS MI -3.06, 95% CI -7.34 to 1.21; ANS MI 4.91, 95% CI -4.79 to 14.62; P > 0.1588). ARS/ANS were grouped by pbp mutations. Group 1 strains exhibited significantly lower amoxicillin resistance (mean MIC 2.8 mg/L, 95% CI 2.6-3.1) than group 2 (mean MIC 9.3 mg/L, 95% CI 8.1-10.5; P < 0.0001). Group 2 strains predominated immediately post-treatment (61.07%) and although decreased by days 28-35 (30.71%), proportions remained higher than baseline (18.70%; P = 0.0004). By utilizing oropharyngeal streptococci as model organisms this study provides the first prospective, experimental evidence that resistance selection in patients receiving amoxicillin is modest and short-lived, probably due to 'fitness costs' engendered by high-level resistance-conferring mutations. This evidence further supports European guidelines that recommend amoxicillin when an antibiotic is indicated for community-acquired lower respiratory tract infections.

Febrile seizure (FS) is a common benign seizure disorder of young children. Although upper respiratory tract infection is the cause of fever in most episodes of FS, studies to identify respiratory viruses using a multiplex polymerase chain reaction (mPCR) test have rarely been performed for children with FS. Medical records of children presenting with FS between January 2015 and December 2019 were retrospectively reviewed. Respiratory viruses identified by a rapid influenza detection test and mPCR test were investigated, and their seasonal distribution and the association between viral identification and seizure characteristics were determined. A total of 607 episodes of FS were analyzed: 81.1% of cases were generalized tonic–clonic seizures, 81.5% occurred within 24 h after fever onset, and 87.3% continued for ≤5 min. Complex FS occurred in 17.5% of FS episodes, and epilepsy was diagnosed in 2.5% of tracked cases. Of the 138 mPCR tests performed in 235 hospitalized episodes of FS, 112 (81.2%) tested positive for respiratory viruses: rhinovirus, enterovirus, adenovirus, and influenza virus were most frequently identified. The identified respiratory viruses showed similar seasonal distributions as were observed in community-acquired respiratory tract infections. The identification of a specific respiratory virus was not significantly associated with seizure characteristics or the development of complex FS. In conclusion, respiratory viruses, showing similar seasonal distributions with community-acquired respiratory tract infections and no significant association with the severity and outcomes of FS, should not be rigorously tested for in children with FS.

The In Vitro activity of telithromycin, a new ketolide, was compared with β-lactam antimicrobials against pathogens commonly associated with community-acquired respiratory tract infections. These pathogens were collected during 1999-2000 as part of the ongoing PROTEKT surveillance study. Globally, penicillin non-susceptibility among Streptococcus pneumoniae (n=3362) was 36.3%, ranging from 21.5% (Australasia) to 68.0% (Far East). Telithromycin showed higher potency (MIC90 0.12 mg/L) than β-lactams against S. pneumoniae; 99.9% of all and 99.6% of multi-resistant isolates were susceptible to telithromycin. Among Streptococcus pyogenes isolates (n=1485), 100% were susceptible to β-lactams, and the telithromycin MIC50 and MIC90 were both 0.015 mg/L. Among Haemophilus influenzae (n=2948), 16.6% produced β-lactamase, which reduced the activity of ampicillin, cefaclor and cefprozil. 99.9% of H. influenzae were susceptible to telithromycin and the MIC range for M. catarrhalis was 0.004-0.5 mg/L. The first year results of PROTEKT confirmed high potency for telithromycin against common respiratory tract pathogens, including β-lactam-resistant strains.