The rise of macrolide-resistant Mycoplasma pneumoniae (MRMP), marked bypoint mutations in the 23S rRNA gene, poses a growing global concern since its initial detection in 2001. The prominence of the A2063G mutation during this emergence remains unexplained. This study aimed to clarify the possibility of detecting MRMP from recent clinical macrolide-susceptible M. pneumoniae by exposure to azithromycin (AZM), which has a long half-life and was launched immediately before the first MRMP detection. Six strains isolated from Japanese children in 2019 and reference strain (FH), all belonging to the recent dominant P1 genotype, two or two subtype, were cultivated in a medium containing slightly higher concentrations than the originated minimum inhibitory concentration (MIC) of AZM and underwent sequencing if they grew. Four out of the seven strains grew after exposure to AZM, and C2617G, C2617A were detected, with no mutation in two strains. After another cultivation and sequencing, two of four strains grew and one was changed from C2617G to A2063G, and the other remained C2617A. The MIC of AZM in A2063G strains was 128 mg/mL; for C2617A, it was 0.0156 mg/mL. This is the first study to detect the strains with A2063G mutation from recent macrolide-susceptible M. pneumoniae using AZM exposure.

In the current study we test the hypothesis that the consumption of macrolides in food-animals is positively associated with the prevalence of macrolide resistance in M. pneumoniae at a country-level. The prevalence of M. pneumoniae macrolide resistance was positively associated with the consumption of macrolides for both food animals (Rho = 0.66; P=0.007) and humans (Rho = 0.54; P=0.040). Linear regression analysis revealed that macrolide consumption in food animals but not humans was borderline significantly associated with macrolide resistance (coef. 5547 [95% CI -596-11691] and coef. 0.006 [95% CI -0.008-0.020], respectively).

CC16 plays many protective roles within the lung; however, the complete biological functions, es-pecially regarding the pulmonary epithelium during infection, remain undefined. We have previ-ously shown that CC16 deficient (CC16-/-) mouse tracheal epithelial cells (MTECs) have enhanced Mp burden, compared to CC16 sufficient (WT) MTECs; therefore, in this study, we wanted to fur-ther define how the pulmonary epithelium responds to infection in the context of CC16 deficiency. Using mass spectrometry and quantitative proteomics to analyze proteins secreted apically from MTECs grown at an air-liquid interface, we investigated the protective effects that CC16 elicits within the pulmonary epithelium during Mycoplasma pneumoniae (Mp) infection. When chal-lenged with Mp, WT MTECs have an overall reduction in apical protein secretion, whereas CC16-/- MTECs have increased apical protein secretion compared to their unchallenged controls. Fol-lowing Gene Ontology and Kyoto Encyclopedia of Genes and Genomes (KEGG) assessment, many of the proteins upregulated from CC16-/- MTECS (unchallenged and during Mp infection) were related to airway remodeling, which were not observed by WT MTECs. These findings sug-gest that CC16 is instrumental in providing protection within the pulmonary epithelium during respiratory infection with Mp, the major causative agent of community-acquired pneumoniae.

Antibiotics’ effect on Mycoplasma pneumoniae (MP) infection still remains controversial. A prospective study of 257 children with MP pneumonia during a recent epidemic (2015-2016) was conducted. All MP pneumonia patients were treated with corticosteroids within 24-36 h after admission. Initially, oral prednisolone (1 mg/kg) or intravenous methylprednisolone (IVMP) (1-2 mg/kg) was administered for mild pneumonia patients, and IVMP (5 -10 mg/kg/day) for severe pneumonia patients. If patients showed persistent fever for 36-48 hours or disease progression, additive IVMP (5 mg/kg or 10 mg/kg) was given. Eighty-five patients received only a broad-spectrum antibiotic without macrolide. The mean age and the male:female ratio were 5.6 ± 3.1 years, respectively. Seventy-four percent of patients (190/257) showed immediate defervescence within 24 h, and 95.7% (246/257) of patients showed defervescence within 72 h with improvements in clinical symptoms. Eight patients who received additive IVMP also showed clinical improvement within 48 h without adverse reactions. There were no clinical or laboratory differences between patients treated with a macrolide (n = 172) and without (n = 85). Early corticosteroid therapy might reduce disease morbidity and prevent disease progression in MP pneumonia patients without side effects, and antibiotics may have limited effects on MP infection.

Members of the genus Mycoplasma and related organisms impose a substantial burden of infectious diseases on humans and animals, but the last comprehensive review of mycoplasmal pathogenicity was published 20 years ago. Post-genomic analyses have now begun to support the discovery and detailed molecular biological characterization of a number of specific mycoplasmal virulence factors. This review covers three categories of defined mycoplasmal virulence effectors: 1) specific macromolecules including the superantigen MAM, the ADP-ribosylating CARDS toxin, sialidase, cytotoxic nucleases, cell-activating diacylated lipopeptides, and phosphocholine-containing glycoglycerolipids; 2) the small molecule effectors hydrogen peroxide, hydrogen sulfide, and ammonia; and 3) several putative mycoplasmal orthologs of virulence effectors documented in other bacteria. Understanding such effectors and their mechanisms of action at the molecular level connects the biology of the bacteria to direct effects on the host and host responses they elicit, and is expected to translate into new interventions for human and veterinary mycoplasmosis.

Mycoplasma synoviae (MS) is a highly contagious bacteria that can cause significant harm in commercial poultry populations while not prevented. Rapid detection of its presence in a flock is crucial from the perspective of animals' health and economic income. Authors propose spectral measurements strongly backed up by the AI data processing algorithms for classifying egg origin: from healthy hens or MS-infected ones. The newest obtained classification factors are F-scores for white eggshells 99% and for brown eggshells 99%—all data used for classification were taken by the portable multispectral fibre-optics reflectometer.