Pneumoniae-positive Samples Research Articles

Molecular typing of Mycoplasma pneumoniae and its correlation with macrolide resistance in children in Henan of China

Background/purposeAs a major causative pathogen of community-acquired pneumonia, Mycoplasma pneumoniae (M. pneumoniae) can cause both upper and lower respiratory tract inflammation as well as extrapulmonary syndromes, especially in infants and the elderly. The emergence of macrolide–resistance has significant effects on the treatment of relevant diseases in children. This study aimed to analyze the genotypes and the macrolide resistance-associated mutations in M. pneumoniae sampled from the pediatric patients in Henan, China. MethodsA segment of gene on the 23S rRNA was amplified and sequenced to detect the mutations related to macrolide resistance. Molecular typing was performed by the method named multiple locus variable-number tandem repeat analysis (MLVA) for macrolide-susceptible and macrolide-resistant specimens. ResultsAmong the M. pneumoniae-positive samples, 95.7% (111/116) had macrolide-resistant mutation, and all of them consisted of the A2063G mutation. There were only two MLVA types identified in this study, type 4-5-7-2 (51/92, 55.4%) and type 3-5-6-2 (41/92, 44.6%). ConclusionThere was no correlation between MLVA types and macrolide resistance (P ​> ​0.05).

Point-of-care molecular diagnosis of Mycoplasma pneumoniae including macrolide sensitivity using quenching probe polymerase chain reaction.

ObjectivesMacrolides are generally considered to be the drugs of choice for treatment of patients with Mycoplasma pneumoniae infection. However, macrolide-resistant M. pneumoniae has been emerging since about 2000. The Smart Gene® system (MIZUHO MEDY Co., Ltd., Tosu, Japan) is a novel fully automated system for detection of pathogens using the method of quantitative polymerase chain reaction (qPCR) with QProbe (QProbe PCR). The entire procedure is completed within 50 min and the size of the instrument is small (15 x 34 x 30 cm). The purpose of this study was to evaluate the usefulness of the Smart Gene® system for detection of M. pneumoniae and detection of a point mutation at domain V of the 23S rRNA gene of M. pneumoniae.MaterialsPharyngeal swab samples were collected from 154 patients who were suspected of having respiratory tract infections associated with M. pneumoniae.ResultsCompared with the results of qPCR, the sensitivity and specificity of the Smart Gene® system were 98.7% (78/79) and 100.0% (75/75), respectively. A point mutation at domain V of the 23S rRNA gene was detected from 7 (9.0%) of 78 M. pneumoniae-positive samples by the Smart Gene® system and these results were confirmed by direct sequencing. The minimum inhibitory concentrations of clarithromycin among the 5 isolates of M. pneumoniae with a point mutation at domain V of the 23S rRNA gene were >64 μg/ml and those among the 33 isolates without a mutation in the 23S rRNA gene were <0.0625 μg/ml.ConclusionThe Smart Gene® system is a rapid and accurate assay for detection of the existence of M. pneumoniae and a point mutation at domain V of the 23S rRNA gene of M. pneumoniae at the same time. The Smart Gene® system is suitable for point-of-care testing in both hospital and outpatient settings.

Mycoplasma pneumoniae infections, 11 countries in Europe and Israel, 2011 to 2016.

BackgroundMycoplasma pneumoniae is a leading cause of community-acquired pneumonia, with large epidemics previously described to occur every 4 to 7 years.AimTo better understand the diagnostic methods used to detect M. pneumoniae; to better understand M. pneumoniae testing and surveillance in use; to identify epidemics; to determine detection number per age group, age demographics for positive detections, concurrence of epidemics and annual peaks across geographical areas; and to determine the effect of geographical location on the timing of epidemics.MethodsA questionnaire was sent in May 2016 to Mycoplasma experts with national or regional responsibility within the ESCMID Study Group for Mycoplasma and Chlamydia Infections in 17 countries across Europe and Israel, retrospectively requesting details on M. pneumoniae-positive samples from January 2011 to April 2016. The Moving Epidemic Method was used to determine epidemic periods and effect of country latitude across the countries for the five periods under investigation.ResultsRepresentatives from 12 countries provided data on M. pneumoniae infections, accounting for 95,666 positive samples. Two laboratories initiated routine macrolide resistance testing since 2013. Between 2011 and 2016, three epidemics were identified: 2011/12, 2014/15 and 2015/16. The distribution of patient ages for M. pneumoniae-positive samples showed three patterns. During epidemic years, an association between country latitude and calendar week when epidemic periods began was noted.ConclusionsAn association between epidemics and latitude was observed. Differences were noted in the age distribution of positive cases and detection methods used and practice. A lack of macrolide resistance monitoring was noted.

Multiple-locus variable-number tandem-repeat analysis (MLVA) of macrolide-susceptible and -resistant Mycoplasma pneumoniae in children in Taiwan

Background/purposeTo date, molecular typing studies on Mycoplasma pneumoniae are limited. We evaluated the molecular types of Mycoplasma pneumoniae in pediatric patients in Taiwan in 2016. MethodsWe used real-time quantitative PCR on respiratory specimens to identify M. pneumoniae in children with community-acquired pneumonia. The domain V of their 23S rRNA were sequenced for detection of macrolide-resistant point mutations. Molecular typing with multiple locus variable-number tandem repeat analysis (MLVA) was done for both macrolide-susceptible and -resistance M. pneumoniae samples. ResultsM. pneumoniae was detected in 22% (180/826) respiratory samples during the study period. Among all M. pneumoniae-positive samples, 24% (43/180) had harbored macrolide-resistant genotypes, and 86% (37/43) of them were A2063G mutation. Forty-two macrolide-resistant strains and 20 randomly selected macrolide-susceptible strains underwent MLVA profiling. MLVA 4-5-7-2 was the most frequent type (32/62, 52%), followed by 4-5-7-3 (17/62, 27%) and 1-5-6-2 (9/62, 15%). There was a strong association between MLVA 4-5-7-2 and macrolide resistance (p < 0.001). In contrast, M 4-5-7-3 and 1-5-6-2 were related to macrolide susceptibility (p < 0.001, and p = 0.025, respectively). ConclusionMacrolide resistance was relatively low (24%) in this age group in 2016 in Taiwan, and A2063G was the dominant point mutation. MLVA 4-5-7-2 was associated with macrolide resistance.

Allele-specific real-time PCR testing for minor macrolide-resistant Mycoplasma Pneumoniae

BackgroundThe point mutations in 23S rRNA gene of Mycoplasma pneumoniae (M. pneumoniae) can lead to high-level resistance to macrolides. This study aimed to evaluate allele-specific real-time PCR (ASPCR) to detect the resistance-related mutations located at positions A2063G and A2064G of 23S rRNA gene.MethodsWe detected 178 pharyngeal swab specimens and calculated the proportions of resistant and sensitive quasispecies using ASPCR assays. ASPCR assays can detect down to 10 copies of 23S rRNA gene and achieved sensitivities of < 0.1% for A2063G and A2064G. We also compared the findings of ASPCR with the results of nested PCR with sequencing.ResultsOf 178 samples, 164 were found to have M. pneumoniae including 90.85% (149/164) samples with macrolide-resistant M. pneumoniae (MRMP) quasispecies by ASPCR, while 153 were found to be M. pneumoniae-positive including 71.90% (110/153) samples with MRMP quasispecies by nested PCR with sequencing. Of the 164 M. pneumoniae-positive samples, 61.59% (101/164) had the mixed population of wild-type and mutant M. pneumoniae, and 56.44% (57/101) of the latter contained the mutations at low frequency (≤50%).ConclusionASPCR indicated that sensitive and resistant quasispecies coexisted in most of the M. pneumoniae positive samples. The ASPCR was a highly sensitive, accurate and rapid method for detecting the macrolide resistance-associated mutations and it could provide earlier and more drug-resistant information for M. pneumoniae research and the clinical therapy.

First Description of Macrolide-Resistant Mycoplasma pneumoniae in Adults with Community-Acquired Pneumonia in Italy.

Background Mycoplasma pneumoniae is a common cause of community-acquired pneumonia (CAP). This cross-sectional study aimed to determine the prevalence of macrolide-resistant M. pneumoniae strains in a convenience series of 234 adult hospitalised and nonhospitalised subjects with a diagnosis of CAP in January 2013 to April 2015 in South Italy. Methods Respiratory samples were subjected to real-time PCR. In M. pneumoniae-positive samples, domain V of 23S rRNA was sequenced to detect resistance-conferring point mutations. P1 major adhesion protein typing and multiple loci variable-number tandem repeat analysis (MLVA) were also performed. Results Of the 234 samples, 15 (6.4%) were positive for M. pneumoniae. Three of these had a macrolide-resistant genotype: two and one had A2063G and A2064G mutations, respectively. Fourteen of the 15 strains were subtyped: half had subtype 1 and half had subtype 2. Eight strains underwent MLVA profiling: one each had the J, A, and Z type. The remainder was unclassifiable. Conclusions This novel discovery of macrolide-resistant M. pneumoniae strains in adults with CAP in Italy suggests that there may be increasing circulation of these strains in the population. To facilitate rapid optimization of the antibiotic strategy in Italy, macrolide resistance should be monitored by a surveillance system that is based on molecular methods.

Mycoplasma pneumoniaeandChlamydiaspp. Infection in Community-Acquired Pneumonia, Germany, 2011–2012

Mycoplasma pneumoniae and Chlamydia spp., which are associated with community-acquired pneumonia (CAP), are difficult to propagate, and can cause clinically indistinguishable disease patterns. During 2011-2012, we used molecular methods to test adult patients in Germany with confirmed CAP for infection with these 2 pathogens. Overall, 12.3% (96/783) of samples were positive for M. pneumoniae and 3.9% (31/794) were positive for Chlamydia spp.; C. psittaci (2.1%) was detected more frequently than C. pneumoniae (1.4%). M. pneumoniae P1 type 1 predominated, and levels of macrolide resistance were low (3.1%). Quarterly rates of M. pneumoniae-positive samples ranged from 1.5% to 27.3%, showing a strong epidemic peak for these infections, but of Chlamydia spp. detection was consistent throughout the year. M. pneumoniae-positive patients were younger and more frequently female, had fewer co-occurring conditions, and experienced milder disease than did patients who tested negative. Clinicians should be aware of the epidemiology of these pathogens in CAP.

Single-nucleotide polymorphism PCR for the detection of Mycoplasma pneumoniae and determination of macrolide resistance in respiratory samples

The aim of this study was to develop a single-nucleotide polymorphism (SNP) PCR assay to be performed directly on respiratory samples for the simultaneous detection of Mycoplasma pneumoniae and its 23S rRNA gene mutations, which are responsible for macrolide resistance. For multiplex SNP PCR, two outer primers for amplification of the 23S rRNA gene and two mutant-specific primers for the discrimination of single base changes were designed. A total of 73M. pneumoniae-positive samples and 100M. pneumoniae-negative samples were analyzed using this assay. By SNP PCR, we detected two mutations conferring high-level macrolide resistance in 22 samples (A2063G from 20 and A2064G from 2 samples); these results are identical to those produced by the 23S rRNA gene sequencing of M. pneumoniae-positive samples. Thus, this assay can be used as a practical method for the simultaneous detection of M. pneumoniae and mutations associated with macrolide resistance directly from respiratory samples.

Infectious Chlamydia pneumoniae is Associated With Elevated Interleukin-8 and Airway Neutrophilia in Children With Refractory Asthma

Neutrophilic asthma is thought to be less responsive than eosinophilic asthma to anti-inflammatory therapies including corticosteroids. Chlamydia pneumoniae has been implicated in asthma, possibly by induction of interleukin (IL-8). We hypothesized that IL-8 is increased in the bronchoalveolar lavage (BAL) fluid from children with asthma and C. pneumoniae. BAL fluid was analyzed for C. pneumoniae and IL-8 using polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay from 2 asthma patient populations in the Bronx, NY and Massachusetts with an average age of 8 and 8.7 years old, respectively. For comparison, samples were also analyzed for C. trachomatis and Mycoplasma 16s DNA. Of 18 Bronx samples analyzed, 6 (33%) were PCR-positive for C. pneumoniae, 10 (56%) for C. trachomatis, and 8 (44%) for Mycoplasma 16s DNA. IL-8 from C. pneumoniae-positive samples was 3.3-fold higher compared with negative samples (P = 0.003). There was no difference between patients tested for C. trachomatis or Mycoplasma. Of 84 Massachusetts samples analyzed, 42 (50%) were PCR-positive for C. pneumoniae, 42 (50%) for C. trachomatis, and 13 (16%) for Mycoplasma. IL-8 concentration from C. pneumoniae-positive samples was 10.49-fold higher compared with negative samples (P = 0.0001). As in the Bronx cohort, there were no differences between patients tested for C. trachomatis or Mycoplasma. Lastly, BAL neutrophilia predicted the presence of C. pneumoniae but not Mycoplasma or C. trachomatis. Children with asthma who were PCR-positive for C. pneumoniae demonstrated elevated concentrations of IL-8 and neutrophils in BAL fluid compared with similar patients who were positive for C. trachomatis or Mycoplasma organisms, but PCR-negative for C. pneumoniae. Undiagnosed C. pneumoniae infection in children may therefore contribute to poorly controlled asthma via induction of IL-8.