Moraxella catarrhalis in acute laryngitis: infection or colonization?

Association between Moraxella keratitis and advanced glycation end products

Diabetes mellitus is recognized as a major predisposing factor for Moraxella keratitis. However, how diabetes mellitus contributes to Moraxella keratitis remains unclear. In this study, we examined Moraxella keratitis; based on the findings, we investigated the impact of advanced glycation end products (AGEs) deposition in the cornea of individuals with diabetic mellitus on the adhesion of Moraxella isolates to the cornea. A retrospective analysis of 27 culture-proven cases of Moraxella keratitis at Ehime University Hospital (March 2006 to February 2022) was performed. Moraxella isolates were identified using matrix-assisted laser desorption ionization time-of-flight mass spectrometry. Among the patients, 30.4% had diabetes mellitus and 22.2% had the predominant ocular condition of using steroid eye drops. The species identified were Moraxella nonliquefaciens in 59.3% and Moraxella lacunata in 40.7% of patients. To investigate the underlying mechanisms, we assessed the effects of M. nonliquefaciens adherence to simian virus 40-immortalized human corneal epithelial cells (HCECs) with or without AGEs. The results demonstrated the number of M. nonliquefaciens adhering to HCECs was significantly increased by adding AGEs compared with that in controls (p < 0.01). Furthermore, in the corneas of streptozotocin-induced diabetic C57BL/6 mice treated with or without pyridoxamine, an AGE inhibitor, the number of M. nonliquefaciens adhering to the corneas of diabetic mice was significantly reduced by pyridoxamine treatment (p < 0.05). In conclusion, the development of Moraxella keratitis may be significantly influenced by the deposition of AGEs on the corneal epithelium of patients with diabetes mellitus.

Multilocus sequence typing-based analysis of Moraxella catarrhalis population structure reveals clonal spreading of drug-resistant strains isolated from childhood pneumonia

This work revealed the drug resistance and population structure of Moraxella catarrhalis strains isolated from children less than three years old with pneumonia. Forty-four independent M. catarrhalis strains were analyzed using broth dilution antimicrobial susceptibility testing and multilocus sequence typing (MLST). The highest non-susceptibility rate was observed for amoxicillin (AMX), which reached 95.5%, followed by clindamycin (CLI) (n=33; 75.0%), azithromycin (AZM) (61.4%), cefaclor (CEC) (25.0%), trimethoprim-sulfamethoxazole (SXT) (15.9%), cefuroxime (CXM) (4.5%), tetracycline (TE) (2.3%), and doxycycline (DOX) (2.3%). There was no strain showing non-susceptibility to other six antimicrobials. Using MLST, the 44 M. catarrhalis strains were divided into 33 sequence types (STs). Based on their allelic profiles, the 33 STs were divided into one CC (CC363) and 28 singletons. CC363 contained five STs and ST363 was the founder ST. CC363 contained 63.6%, 33.3%, and 40.7% of CEC non-susceptible, CLI non-susceptible and AZM non-susceptible strains, respectively. The proportions of CEC non-susceptible, CLI non-susceptible and AZM non-susceptible strains in CC363 were higher than that of singletons; these differences were significant for CEC (p=0.002) and AZM (p=0.011). Furthermore, CC363 contained more AMX-CLI-AZM co-non-susceptible and AMX-CEC-CLI-AZM co-non-susceptible strains than the singletons (p=0.007 and p<0.001, respectively). CC363 is a drug-resistant clone of clinical M. catarrhalis strains in China. Expansion of this clone under selective pressure of antibiotics should be noted and long-term monitoring should be established.

Moraxella catarrhalis Macrolide-Resistant Isolates Are Highly Concentrated in Two MLST Clonal Complexes -CCN10 and CC363

To gain some insights into the molecular evolution of Moraxella catarrhalis macrolide resistance, PCR and sequencing analysis of the 23S rRNA gene, copB typing and multilocus sequence typing (MLST) were performed on 181 M. catarrhalis isolates. The isolates were obtained from children (n = 47) and adults (n = 134) presenting with respiratory disease in the years 2010–2014. Macrolide resistance was highly age-related, and nucleotide position alterations at A2330T could be detected in all macrolide-resistant isolates. copB 0 and copB NT (non-typable) were only found in macrolide-susceptible isolates from adults. Furthermore, copB I/III was the main type in adult or macrolide-susceptible isolates, while copB II was the most common type in children or macrolide-resistant isolates. Twenty-two different MLST clusters (sharing 7 of the 8 identical loci) were detected and only four likely primary founders (ST224, ST363, STN08, and STN10) which belong to clonal complex (CC) 224, CC363, CCN08, and CCN10, were detected, respectively. Macrolide-resistant M. catarrhalis isolates were highly concentrated in two CCs (CCN10 and CC363), which indicates some potential evolutionary advantage or co-evolution to some extent. However, further studies are needed to fully elucidate the evolution of CCN10 and CC363 in macrolide resistance.

Antibiotics for acute laryngitis in adults

BACKGROUND

This is an update of the original review published in 2005. Acute laryngitis is a common illness worldwide. Diagnosis is often made by case history alone and treatment often targets symptoms.

OBJECTIVES

To assess the effectiveness and safety of different antibiotic therapies in adults with acute laryngitis. A secondary objective was to report the rates of adverse events associated with these treatments.

SEARCH METHODS

We searched CENTRAL (2014, Issue 11), MEDLINE (January 1966 to November week 3, 2014), EMBASE (1974 to December 2014), LILACS (1982 to December 2014) and BIOSIS (1980 to December 2014).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any antibiotic therapy with placebo for acute laryngitis. The main outcome was objective voice scores.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and synthesised data.

MAIN RESULTS

We included three RCTs (351 participants) that had moderate to high risk of bias. The quality of the evidence was very low for all outcomes. We downgraded the studies because of limitations in study design or execution (risk of bias), imprecision and inconsistency of results. We included a new trial presented only as a conference abstract in this update.In one study of acute laryngitis in adults, 100 participants were randomised to receive penicillin V (800 mg twice daily for five days) or an identical placebo. A recording of each patient reading a standardised text was made at the first visit, during re-examination after one and two weeks, and at follow-up after two to six months. No significant differences were found between the groups. The trial also measured symptoms reported by participants and found no significant differences.One study investigated erythromycin for acute laryngitis in 106 adults. The mean objective voice scores measured at the first visit, at re-examination after one and two weeks, and at follow-up after two to six months did not significantly differ between the groups. At one week there were significant beneficial differences in the severity of reported vocal symptoms (slight, moderate and severe) as judged by participants (P value = 0.042). However, the rates of participants having improved voice disturbance (subjective symptoms) at one and two weeks were not significantly different among groups. Comparing erythromycin and placebo groups on the rate of persistence of cough at two weeks, the risk ratio (RR) was 0.38 (95% confidence interval (CI) 0.15 to 0.97, P value = 0.04) and the number needed to treat for an additional beneficial outcome (NNTB) was 5.87 (95% CI 3.09 to 65.55). We calculated a RR of 0.64 (95% CI 0.46 to 0.90, P value = 0.034) and a NNTB of 3.76 (95% CI 2.27 to 13.52; P value = 0.01) for the subjective voice scores at one week.A third trial from Russia included 145 patients with acute laryngitis symptoms. Participants were randomised to three treatment groups: Group 1: seven-day course of fusafungine (six times a day by inhalation); Group 2: seven-day course of fusafungine (six times a day by inhalation) plus clarithromycin (250 mg twice daily for seven days); Group 3: no treatment. Clinical cure rates were measured at days 5 ± 1, 8 ± 1 and 28 ± 2. The authors reported significant differences in the rates of clinical cure at day 5 ± 1 favouring fusafungine (one trial; 93 participants; RR 1.50, 95% CI 1.02 to 2.20; P value = 0.04) and fusafungine plus clarithromycin (one trial 97 participants; RR 1.47, 95% CI 1.00 to 2.16; P value = 0.05) when compared to no treatment. However, no significant differences were found at days 8 ± 1 and 28 ± 2. Also, no significant differences were found when comparing fusafungine to fusafungine plus clarithromycin at days 5 ± 1, 8 ± 1 and 28 ± 2.

AUTHORS' CONCLUSIONS

Antibiotics do not appear to be effective in treating acute laryngitis when assessing objective outcomes. They appear to be beneficial for some subjective outcomes. Erythromycin could reduce voice disturbance at one week and cough at two weeks when measured subjectively. Fusafungine could increase the cure rate at day five. The included RCTs had important methodological problems and these modest benefits from antibiotics may not outweigh their cost, adverse effects or negative consequences for antibiotic resistance patterns.

High-Level Macrolide-Resistant Moraxella catarrhalis and Development of an Allele-Specific PCR Assay for Detection of 23S rRNA Gene A2330T Mutation: A Three-Year Study at a Chinese Tertiary Hospital

Previous studies indicate that macrolide resistance in Moraxella catarrhalis isolates is less common in adults than in children. However, few studies have investigated M. catarrhalis macrolide resistance mechanisms in adult patients. In this study, 124 M. catarrhalis isolates were collected from adult patients in a Chinese tertiary hospital, between 2010 and 2013, and investigated for antimicrobial resistance. We found that only seven isolates were macrolide resistant and all exhibited high-level macrolide resistance (minimum inhibitory concentrations >256 μg/ml). Multilocus sequence typing (MLST) suggested that M. catarrhalis has a diverse population; in particular, both pulsed-field gel electrophoresis and MLST revealed that all the seven high-level macrolide-resistant M. catarrhalis belonged to different clones. A 934-bp 23S rRNA gene sequencing showed that only nine isolates (including all the seven macrolide-resistant isolates) had mutations within the studied region, and only the seven macrolide-resistant isolates had mutation of A2330T. No other known macrolide-resistance determinant genes (ermA, ermB, mefA, or mefE) were detected. These findings support previous studies in children on M. catarrhalis macrolide-resistant isolates and suggest that the 23S rRNA gene A2330T mutation is responsible for the high M. catarrhalis macrolide resistance. The findings prompted us to successfully develop a simple allele-specific polymerase chain reaction assay for high-level macrolide-resistant 23S rRNA gene A2330T mutation for future clinical and further surveillance use.

Antibiotics for acute laryngitis in adults

BACKGROUND

This is an updated version of the original review published in Issue 2, 2007 of The Cochrane Library. Acute laryngitis is a common illness worldwide. Diagnosis is often made by case history alone and treatment is often directed toward controlling symptoms.

OBJECTIVES

To assess the effectiveness and safety of different antibiotic therapies in adults with acute laryngitis. A secondary objective was to report the rates of adverse events associated with these treatments.

SEARCH METHODS

We searched CENTRAL 2012, Issue 12, MEDLINE (January 1966 to January week 3, 2013), EMBASE (1974 to January 2013), LILACS (1982 to January 2013) and BIOSIS (1980 to January 2013).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any antibiotic therapy with placebo for acute laryngitis. The main outcome was objective voice scores.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted and descriptively synthesised data.

MAIN RESULTS

Only two trials met the study inclusion criteria after extensive literature searches. One hundred participants were randomised to receive either penicillin V (800 mg twice a day for five days), or an identical placebo, in a study of acute laryngitis in adults. A tape recording of each patient reading a standardised text was obtained during the first visit, subsequently during re-examination after one and two weeks, and at follow-up after two to six months. No significant differences were found between the groups. The trial also measured symptoms reported by participants and found no significant differences.The second trial investigated erythromycin for treating acute laryngitis in 106 adults. The mean objective voice scores measured at the first visit, at re-examination after one and two weeks, and at follow-up after two to six months did not significantly differ between control and intervention groups. At one week there were significant beneficial differences in the severity of reported vocal symptoms as judged by the participants (P = 0.042). Comparing the erythromycin and placebo groups on subjective voice scores, the a priori risk ratio (RR) was 0.7 (95% confidence interval (CI) 0.51 to 0.96, P = 0.034) and the number needed to treat for an additional beneficial outcome (NNTB) was 4.5.

AUTHORS' CONCLUSIONS

Antibiotics appear to have no benefit in treating acute laryngitis. Erythromycin could reduce voice disturbance at one week and cough at two weeks when measured subjectively. We consider that these outcomes are not relevant in clinical practice. The implications for practice are that prescribing antibiotics should not be done in the first instance as they will not objectively improve symptoms.

The other siblings: respiratory infections caused by Moraxella catarrhalis and Haemophilus influenzae

Respiratory infections remain substantial causes of morbidity and mortality globally. In this paper, two substantial players in bacterial-associated respiratory disease are assessed as to their respective roles in children and adults and in the developed and developing world. Moraxella catarrhalis, although initially thought to be a nonpathogen, continues to emerge as a cause of upper respiratory disease in children and pneumonia in adults. No vaccine is currently available to prevent M. catarrhalis infection. Haemophilus influenzae type b, originally thought to be the cause of influenza, has now been limited epidemiologically in the developed world due to an effective immunization but it continues to be a major player in the developing world. Nonencapsulated strains of H. influenzae still remain as significant causes of respiratory infections in the developing world especially in exacerbation of chronic obstructive lung disease. Finally, and in brief, the spectrum of Brazilian purpuric fever due to a specific biotype of H. influenzae is discussed.

Age-related genotypic and phenotypic differences in Moraxella catarrhalis isolates from children and adults presenting with respiratory disease in 2001-2002

Moraxella catarrhalis is generally associated with upper respiratory tract infections in children and lower respiratory tract infections in adults. However, little is known regarding the population biology of isolates infecting these two age groups. To address this, a population-screening strategy was employed to investigate 195 worldwide M. catarrhalis isolates cultured from children (<5 years of age) and adults (>20 years of age) presenting with respiratory disease in the years 2001-2002. Parameters compared included: genotype analysis; autoagglutination/biofilm-forming ability; serum resistance; uspA1, uspA2, uspA2H, hag and mcaP incidence; copB/LOS/ompCD/16S rRNA types; and UspA1/Hag expression. A significant difference in biofilm formation (P=0.002), but not in autoagglutination or serum resistance, was observed, as well as significant differences in the incidence of uspA2- and uspA2H-positive isolates, and the distribution of lipooligosaccharide (LOS) types (P<0.0001 and P=0.01, respectively). Further, a significant decrease in the incidence of Hag expression (for isolates possessing the hag gene) was observed in adult isolates (P=0.001). Both uspA2H and LOS type B were associated with 16S rRNA type 1 isolates only, and two surrogate markers (copB and ompCD PCR RFLP types) for the two major M. catarrhalis 16S rRNA genetic lineages were identified. In conclusion, there are significant differences in phenotype and gene incidence between M. catarrhalis isolates from children and adults presenting with respiratory disease, possibly as a result of immune evasion in the adult age group. Our results should also be useful in the choice of effective vaccine candidates against M. catarrhalis.

Antibiotics for acute laryngitis in adults

BACKGROUND

Acute laryngitis is a common illness worldwide. Diagnosis is often made by case history alone and treatment is often directed towards controlling symptoms.

OBJECTIVES

The aim of this review was to assess the effectiveness of different antibiotic therapies in adults suffering acute laryngitis. A secondary objective was to report the rates of adverse events associated with these treatments.

SEARCH STRATEGY

We systematically screened the following electronic databases: the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 4, 2006); MEDLINE (January 1966 to December Week 2 2006); and EMBASE (1974 to June 2006), LILACS (from 1982 to December 2006 ) and BIOSIS (1980 to June 2002). Other strategies included hand searching relevant journals, searching ongoing trial databases and general databases such as Google scholar.

SELECTION CRITERIA

Randomized controlled trials comparing any antibiotic therapy with placebo in acute laryngitis. The main outcome measurement was objective voice scores.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by two review authors and then descriptively synthesized.

MAIN RESULTS

Only two trials met study inclusion criteria after extensive literature searches. One hundred participants were randomly selected to receive either penicillin V (800 mg twice a day for five days), or an identical placebo, in a study of penicillin V in acute laryngitis in adults. A tape recording of each patient reading a standardized text was obtained during the first visit, subsequently during re-examination after one and two weeks, and at follow up after two to six months. No significant differences were found between the groups. The trial also measured symptoms reported by participants and found no significant differences. The second trial investigated erythromycin for treating acute laryngitis in 106 adults. The mean objective voice scores measured at the first visit, at re-examination after one and two weeks, and at follow up after two to six months did not significantly differ between control and intervention groups. At one week there were significant beneficial differences in the severity of reported vocal symptoms as judged by the participants (P = 0.042). Comparing the erythromycin and placebo groups on subjective voice scores the a priori relative risk (RR) was 0.7 (95% confidence interval (CI) 0.51 to 0.96, P = 0.034) and the number needed to treat (NNT) was 4.5.

AUTHORS' CONCLUSIONS

Antibiotics appear to have no benefit in treating acute laryngitis. Erythromycin could reduce voice disturbance at one week and cough at two weeks when measured subjectively. We consider that these outcomes are not relevant in clinical practice. The implications for practice are that prescribing antibiotics should not be done in the first instance as they will not objectively improve symptoms.

Antibiotics for acute laryngitis in adults

BACKGROUND

Acute laryngitis is a common illness worldwide. Diagnosis is often made by case history alone and treatment is often directed towards controlling symptoms.

OBJECTIVES

The aim of this review was to assess the effectiveness of different antibiotic therapies in adults suffering acute laryngitis. A secondary objective was to report the rates of adverse events associated with these treatments.

SEARCH STRATEGY

We systematically screened the following electronic databases: the Cochrane Central Register of Controlled Trials (The Cochrane Library Issue 3, 2004); MEDLINE (January 1966 to June Week 3 2004); and EMBASE (1974 to June 2004), LILACS (from 1982 to the 40th edition) and BIOSIS (1980 to June 2002). Other strategies included hand searching relevant journals, searching ongoing trial databases and general databases such as Alta Vista.

SELECTION CRITERIA

Randomized controlled trials comparing any antibiotic therapy with placebo in acute laryngitis. The main outcome measurement was objective voice scores.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by two people and then descriptively synthesised.

MAIN RESULTS

Only two trials met study inclusion criteria after extensive literature searches. One hundred patients were randomly selected to receive either penicillin V (800 mg twice a day for five days), or an identical placebo, in a study of penicillin V in acute laryngitis in adults. A tape recording of each patient reading a standardised text was obtained during the first visit, subsequently during re-examination after one and two weeks, and at follow up after two to six months. No significant differences were found between the groups. The trial also measured symptoms reported by patients and found no significant differences. The second trial investigated erythromycin for treating acute laryngitis in 106 adults. The mean objective voice scores measured at the first visit, at re-examination after one and two weeks, and at follow up after two to six months did not significantly differ between control and intervention groups. At one week there were significant beneficial differences in the severity of reported vocal symptoms as judged by the patients (p = 0.042). Comparing the erythromycin and placebo groups on subjective voice scores the a priori relative risk (RR) was 0.7 (95% confidence interval (CI) 0.51 to 0.96, p = 0.034) and the number needed to treat (NNT) was 4.5.

AUTHORS' CONCLUSIONS

Antibiotics appear to have no benefit in treating acute laryngitis. Erythromycin could reduce voice disturbance at one week and cough at two weeks when measured subjectively. We consider that these outcomes are not relevant in clinical practice. The implications for practice are that prescribing antibiotics should not be done in the first instance as they will not objectively improve symptoms.

Production of BRO beta-lactamases and resistance to complement in European Moraxella catarrhalis isolates

Of the 419 Moraxella catarrhalis isolates collected during the 1997-1999 European SENTRY surveillance study, 385 (92%) were beta-lactamase positive. Twenty-two (5.7%) produced BRO-2 beta-lactamase. Twenty-one new mutations were found in the putative promoter region of the bro genes. Nineteen percent of all isolates tested were complement sensitive. Resistance to beta-lactams is not linked to the phylogenetic lineages associated with susceptibility to complement.

Moraxella catarrhalis: clinical significance, antimicrobial susceptibility and BRO beta-lactamases

Moraxella catarrhalis is an important pathogen of humans. It is a common cause of respiratory infections, particularly otitis media in children and lower respiratory tract infections in the elderly. Colonisation of the upper respiratory tract appears to be associated with infection in many cases, although this association is not well understood. Nosocomial transmission is being increasingly documented and the emergence of this organism as a cause of bacteremia is of concern. The widespread production of a beta-lactamase enzyme renders Moraxella catarrhalis resistant to the penicillins. Cephalosporins and beta-lactamase inhibitor combinations are effective for treatment of beta-lactamase producers, and the organism remains nearly universally susceptible to the macrolides, fluoroquinolones, tetracyclines and the combination of trimethoprim and sulfamethoxazole. Two major beta-lactamase forms, BRO-1 and BRO-2, have been described on the basis of their isoelectric focusing patterns. The BRO-1 enzyme is found in the majority of beta-lactamase-producing isolates and confers a higher level of resistance to strains than BRO-2. The BRO enzymes are membrane associated and their production appears to be mediated by chromosomal determinants which are transmissible by an unknown mechanism. The origin of these novel proteins is unknown.