The detection of clinical isolates with decreased fluoroquinolone susceptibilities and a resistance mechanism is of epidemiological and clinical interest. We studied the susceptibilities of 62 clinical isolates and 2 American Type Culture Collection reference strains of Haemophilus influenzae to ciprofloxacin, levofloxacin, moxifloxacin, and nalidixic acid by the microdilution and disk diffusion methods. The ciprofloxacin MICs for 34 of the isolates were >/=0.12 micro g/ml (range, 0.12 to 32 micro g/ml), and the ciprofloxacin MICs for 28 matched control isolates were =0.06 micro g/ml. In addition, we sequenced the quinolone resistance-determining regions (QRDRs) of gyrA and parC of all strains. The log(2) MICs of all quinolones were plotted against the inhibition zone diameters. The MICs and inhibition zone diameters selected to screen for the resistance mechanism were based on the susceptibility distribution data and the presence or absence of amino acid changes in the QRDRs of GyrA and ParC. Strains for which ciprofloxacin MICs were =0.06 micro g/ml, levofloxacin and moxifloxacin MICs were =0.03 micro g/ml, and nalidixic acid MICs were =2.0 micro g/ml lacked modifications in the QRDR of GyrA. In contrast, all strains for which ciprofloxacin, levofloxacin, and moxifloxacin MICs were >/=0.5 micro g/ml and the vast majority of those for which nalidixic acid MICs were >/=32 micro g/ml exhibited amino acid changes in GyrA and ParC. Nalidixic acid and the other three fluoroquinolones studied could be used to screen H. influenzae isolates for the detection of decreased susceptibilities to quinolones due to the acquisition of two amino acid changes in the QRDRs of GyrA and ParC (sensitivity, >95%; specificity, >80%).
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http://dx.doi.org/10.1128/JCM.42.3.1185-1191.2004 | DOI Listing |
Int J Mol Sci
December 2024
Department of Chemistry and Biochemistry, Loyola University Chicago, 1032 West Sheridan Road, Chicago, IL 60660, USA.
Based on the inhibitory potencies from earlier reported tetrazole thioether analogs, we now describe the synthesis and inhibition of pyrazole-based inhibitors of -succinyl-l,l-2,6-diaminopimelic acid desuccinylase (DapE) from (DapE). The most potent pyrazole analog bears an aminopyridine amide with an IC of 17.9 ± 8.
View Article and Find Full Text PDFPediatr Pulmonol
January 2025
Department of Pediatrics, Fu Yang People's Hospital, Fuyang, China.
Background: The COVID-19 pandemic has significantly altered the etiological spectrum and epidemiological characteristics of pediatric respiratory diseases, and a profound understanding of these changes is crucial for guiding clinical treatment. The purpose of this study is to analyze the etiological patterns and epidemiological features of pathogens in bronchoalveolar lavage fluid (BALF) from children with pediatric lower respiratory tract infections (LRTIs) after the COVID-19 pandemic, with the aim of providing effective therapeutic evidence for clinical practice.
Methods: This study enrolled pediatric patients diagnosed with LRTIs who were treated and underwent BALF pathogen detection at our hospital from June 1, 2023, to June 1, 2024.
Vaccines (Basel)
December 2024
Department of Host-Microbe Interactions, St. Jude Children's Research Hospital, Memphis, TN 38105, USA.
: Acute otitis media (AOM) is a common pediatric infection worldwide and is the primary basis for pediatric primary care visits and antibiotic prescriptions in children. Current licensed vaccines have been incompletely ineffective at reducing the global burden of AOM, underscoring a major unmet medical need. The complex etiology of AOM presents additional challenges for vaccine development, as it can stem from multiple bacterial species including , , and .
View Article and Find Full Text PDFVaccines (Basel)
November 2024
Laboratory of Proteolytic Enzyme Chemistry, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry of the Russian Academy of Sciences, 117997 Moscow, Russia.
IgA1 protease is one of the virulence factors of , and other pathogens causing bacterial meningitis. The aim of this research is to create recombinant proteins based on fragments of the mature IgA1 protease A-P from serogroup B strain H44/76. These proteins are potential components of an antimeningococcal vaccine for protection against infections caused by pathogenic strains of and other bacteria producing serine-type IgA1 proteases.
View Article and Find Full Text PDFPharmaceutics
December 2024
Department of BioNano Technology, Gachon University, Seongnam 13120, Republic of Korea.
: The development of a five-in-one vaccine microneedle patch (five-in-one MN patch) aims to address challenges in administering vaccines against Diphtheria (DT), Tetanus (TT), Pertussis (wP), Hepatitis B (HBsAg), and type b (Hib). Combining multiple vaccines into a single patch offers a novel solution to improve vaccine accessibility, stability, and delivery efficiency, particularly in resource-limited settings. : The five-in-one MN patch consists of four distinct microneedle arrays: DT and TT vaccines are coated together on one array, while wP, HepB, and Hib vaccines are coated separately on individual arrays.
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