Development of a disk diffusion method for testing Moraxella catarrhalis susceptibility using clinical and laboratory standards institute methods: a SENTRY antimicrobial surveillance program report

Comparative evaluation of propolis nanostructured lipid carriers and its crude extract for antioxidants, antimicrobial activity, and skin regeneration potential

Background

Propolis extracted from beehives has been conferred with natural antimicrobial and antioxidant properties. Hence, it has been recommended as a wound healing therapy. This study investigated the additive value of nanotechnology to the herbal extract, (propolis rebuts), after which we examined its efficacy in wound healing.

Methods

Propolis nanostructured lipid carriers (NLCs) were first prepared using the emulsion-evaporation-solidification method at three concentrations. Then, we compared their flavonoid and phenolic contents and phenolic contents. Their antioxidant, antibacterial, and antifungal effects were also investigated after which, the skin regenerative capacity of propolis-NLCs was assessed using full-thickness skin wounds in rabbits.

Results

This study showed that propolis-NLCs had increased the phenolic and flavonoid contents compared to the raw propolis extract (EXTR) (9-fold and 2-fold, respectively). This increase was reflected in their antioxidant activities, which dramatically increased by 25-fold higher than the propolis-EXTR. Also, propolis-NLCs exhibited a 2-fold higher potent inhibitory effect than propolis-EXTR on Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus), Gram-negative bacterium (Salmonella spp.), and fungus (Candida albicans) microbes (p < 0.0001). Investigations also revealed that treatment of full-thickness skin injuries with propolis-NLCs resulted in significantly higher wound closure compared to propolis-EXTR and the control after two weeks (p < 0.0001).

Conclusion

With a prominent broad-spectrum antibacterial effect propolis-NLCs exhibited higher skin regenerative potency than propolis-EXTR. We also highlighted the additive impact of nanotechnology on herbal extract, which accounted for the increased flavonoid content and hence a better antioxidant and antimicrobial effect and propose it as a potential therapy for wound healing.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-022-03737-4.

Moraxella catarrhalis: A Cause of Concern with Emerging Resistance and Presence of BRO Beta-Lactamase Gene-Report from a Tertiary Care Hospital in South India

Background

Found as a commensal in the upper respiratory tract, Gram-negative diplococcus Moraxella catarrhalis did not hold much importance as an infectious agent for long. The emergence of the first antibiotic-resistant strain of M. catarrhalis was noted in 1977 in Sweden. This has gradually spread worldwide over the years to more than 95% of the strains showing resistance to penicillin now. Penicillin resistance is mediated by the production of beta-lactamases encoded by bro-1 and bro-2 genes that code for beta-lactamases BRO-1 and BRO-2, respectively. The purpose of this study was to explore the trends of antibiotic resistance, the presence of bro genes, and clinical correlation of these findings with the rise in M. catarrhalis was noted in 1977 in Sweden. This has gradually spread worldwide over the years to more than 95% of the strains showing resistance to penicillin now. Penicillin resistance is mediated by the production of beta-lactamases encoded by bro-1 and bro-2 genes that code for beta-lactamases BRO-1 and BRO-2, respectively. The purpose of this study was to explore the trends of antibiotic resistance, the presence of bro genes, and clinical correlation of these findings with the rise in

Methods

Strains of M. catarrhalis was noted in 1977 in Sweden. This has gradually spread worldwide over the years to more than 95% of the strains showing resistance to penicillin now. Penicillin resistance is mediated by the production of beta-lactamases encoded by bro-1 and bro-2 genes that code for beta-lactamases BRO-1 and BRO-2, respectively. The purpose of this study was to explore the trends of antibiotic resistance, the presence of bro genes, and clinical correlation of these findings with the rise in

Results

Fourteen strains of M. catarrhalis was noted in 1977 in Sweden. This has gradually spread worldwide over the years to more than 95% of the strains showing resistance to penicillin now. Penicillin resistance is mediated by the production of beta-lactamases encoded by bro-1 and bro-2 genes that code for beta-lactamases BRO-1 and BRO-2, respectively. The purpose of this study was to explore the trends of antibiotic resistance, the presence of bro genes, and clinical correlation of these findings with the rise in

Conclusion

The increase in antibiotic resistance and beta-lactamase production in M. catarrhalis is a cause of concern. The emerging resistance pattern emphasises the need for an appropriate antibiotic stewardship program in clinical practice. Importance should be given to the monitoring of the trends of antibiotic susceptibility and their usage to prevent the emergence of outbreaks with resistant strains and treatment failures.M. catarrhalis was noted in 1977 in Sweden. This has gradually spread worldwide over the years to more than 95% of the strains showing resistance to penicillin now. Penicillin resistance is mediated by the production of beta-lactamases encoded by bro-1 and bro-2 genes that code for beta-lactamases BRO-1 and BRO-2, respectively. The purpose of this study was to explore the trends of antibiotic resistance, the presence of bro genes, and clinical correlation of these findings with the rise in

Antimicrobial susceptibility and impact of macrolide antibiotics on Moraxella catarrhalis in the upper and lower airways of children with chronic endobronchial suppuration

INTRODUCTION

Moraxella catarrhalis is an important but insufficiently studied respiratory pathogen.

AIM

To determine antibiotic susceptibility and impact of recent antibiotics on M. catarrhalis from children with chronic endobronchial suppuration.

METHODOLOGY

We cultured nasopharyngeal (NP) swabs and bronchoalveolar lavage (BAL) fluids collected from children who were prospectively enrolled in studies of chronic cough and had flexible bronchoscopy performed. Recent β-lactam or macrolide antibiotic use was recorded. M. catarrhalis isolates stored at -80 °C were re-cultured and susceptibility determined to a range of antibiotics including the macrolide antibiotic erythromycin.

RESULTS

Data from concurrently collected NP and BAL specimens were available from 547 children (median age 2.4 years) enrolled from 2007 to 2016. M. catarrhalis NP carriage was detected in 149 (27  %) children and lower airway infection (≥10⁴ c.f.u. ml^-1 BAL) in 67 (12  %) children. In total, 91  % of 222 M. catarrhalis isolates were β-lactamase producers, and non-susceptibility was high to benzylpenicillin (98 %), cefaclor (39 %) and cotrimoxazole (38 %). Overall, >97  % isolates were susceptible to cefuroxime, chloramphenicol, erythromycin and tetracycline; three isolates were erythromycin-resistant (MIC >0.5 mg l^-1). Recent macrolide antibiotics (n=152 children, 28 %) were associated with significantly reduced M. catarrhalis carriage and lower airway infection episodes compared to children who did not receive macrolides; odds ratios 0.19 (95  % CI 0.10-0.35) and 0.15 (0.04-0.41), respectively.

CONCLUSION

Despite the frequent use of macrolides, few macrolide-resistant isolates were detected. This suggests a fitness cost associated with macrolide resistance in M. catarrhalis. Macrolide antibiotics remain an effective choice for treating M. catarrhalis lower airway infection in children with chronic endobronchial suppuration.

Antimicrobial susceptibility to β-lactam antibiotics and production of BRO β-lactamase in clinical isolates of Moraxella catarrhalis from a Japanese hospital

We investigated BRO-β-lactamase production of Moraxella catarrhalis isolates and its antimicrobial susceptibility to β-lactams. Of the 233 isolates, 232 were BRO producers and 224 were BRO-1 producers. Four isolates exhibited elevated ceftriaxone minimum inhibitory concentration (2 μg/mL) and different pulsed-field gel electrophoresis patterns and we expect this number to increase in the near future.

[Bacterial etiology of acute otitis media in Spain in the post-pneumococcal conjugate vaccine era]

INTRODUCTION

Acute otitis media (AOM) is common in children aged <3 years. A pneumococcal conjugate vaccine (PCV) (PCV7; Prevenar, Pfizer/Wyeth, USA) has been available in Spain since 2001, which has a coverage rate of 50-60% in children aged <5 years.

MATERIALS AND METHODS

Children aged ≥3 to 36 months with AOM confirmed by an ear-nose-throat specialist were enrolled at seven centers in Spain (February 2009-May 2012) (GSK study identifier: 111425). Middle-ear-fluid samples were collected by tympanocentesis or spontaneous otorrhea and cultured for bacterial identification. Culture-negative samples were further analyzed using polymerase chain reaction (PCR).

RESULTS

Of 125 confirmed AOM episodes in 124 children, 117 were analyzed (median age: 17 months (range: 3-35); eight AOM episodes were excluded from analyses. Overall, 69% (81/117) episodes were combined culture- and PCR-positive for ≥1 bacterial pathogen; 44% (52/117) and 39% (46/117) were positive for Haemophilus influenzae (Hi) and Streptococcus pneumoniae (Spn), respectively. 77 of 117 episodes were cultured for ≥1 bacteria, of which 63 were culture-positive; most commonly Spn (24/77; 31%) and Hi (32/77; 42%). PCR on culture-negative episodes identified 48% Hi- and 55% Spn-positive episodes. The most common Spn serotype was 19F (4/24; 17%) followed by 19A (3/24; 13%); all Hi-positive episodes were non-typeable (NTHi). 81/117 AOM episodes (69%) occurred in children who had received ≥1 pneumococcal vaccine dose.

CONCLUSIONS

NTHi and Spn were the main etiological agents for AOM in Spain. Impact of pneumococcal vaccination on AOM requires further evaluation in Spain, after higher vaccination coverage rate is reached.

Panel 5: Microbiology and immunology panel

OBJECTIVE

The objective is to perform a comprehensive review of the literature from January 2007 through June 2011 on the virology, bacteriology, and immunology related to otitis media.

DATA SOURCES

PubMed database of the National Library of Medicine.

REVIEW METHODS

Three subpanels with co-chairs comprising experts in the virology, bacteriology, and immunology of otitis media were formed. Each of the panels reviewed the literature in their respective fields and wrote draft reviews. The reviews were shared with all panel members, and a second draft was created. The entire panel met at the 10th International Symposium on Recent Advances in Otitis Media in June 2011 and discussed the review and refined the content further. A final draft was created, circulated, and approved by the panel.

CONCLUSION

Excellent progress has been made in the past 4 years in advancing an understanding of the microbiology and immunology of otitis media. Advances include laboratory-based basic studies, cell-based assays, work in animal models, and clinical studies.

IMPLICATIONS FOR PRACTICE

The advances of the past 4 years formed the basis of a series of short-term and long-term research goals in an effort to guide the field. Accomplishing these goals will provide opportunities for the development of novel interventions, including new ways to better treat and prevent otitis media.