scholarly journals Combinations of Macrolide Resistance Determinants in Field Isolates of Mannheimia haemolytica and Pasteurella multocida

2011 ◽  
Vol 55 (9) ◽  
pp. 4128-4133 ◽  
Author(s):  
Benoit Desmolaize ◽  
Simon Rose ◽  
Cornelia Wilhelm ◽  
Ralf Warrass ◽  
Stephen Douthwaite
Keyword(s):  
Pasteurella Multocida ◽  
Mannheimia Haemolytica ◽  
23S Rrna ◽  
Type I ◽  
Content Type ◽  
Resistance Determinants ◽  
Drug Classes ◽  
Exogenous Genes ◽  
Selection For ◽  
Tract Infections

ABSTRACTRespiratory tract infections in cattle are commonly associated with the bacterial pathogensMannheimia haemolyticaandPasteurella multocida. These infections can generally be successfully treated in the field with one of several groups of antibiotics, including macrolides. A few recent isolates of these species exhibit resistance to veterinary macrolides with phenotypes that fall into three distinct classes. The first class has type I macrolide, lincosamide, and streptogramin B antibiotic resistance and, consistent with this, the 23S rRNA nucleotide A2058 is monomethylated by the enzyme product of theerm(42) gene. The second class shows no lincosamide resistance and lackserm(42) and concomitant 23S rRNA methylation. Sequencing of the genome of a representative strain from this class,P. multocida3361, revealed macrolide efflux and phosphotransferase genes [respectively termedmsr(E) andmph(E)] that are arranged in tandem and presumably expressed from the same promoter. The third class exhibits the most marked drug phenotype, with high resistance to all of the macrolides tested, and possesses all three resistance determinants. The combinations oferm(42),msr(E), andmph(E) are chromosomally encoded and intermingled with other exogenous genes, many of which appear to have been transferred from other members of thePasteurellaceae. The presence of some of the exogenous genes explains recent reports of resistance to additional drug classes. We have expressed recombinant versions of theerm(42),msr(E), andmph(E) genes within an isogenicEscherichia colibackground to assess their individually contributions to resistance. Our findings indicate what types of compounds might have driven the selection for these resistance determinants.

scholarly journals Multiplex PCR To Identify Macrolide Resistance Determinants in Mannheimia haemolytica and Pasteurella multocida

2012 ◽  
Vol 56 (7) ◽  
pp. 3664-3669 ◽  
Author(s):  
Simon Rose ◽  
Benoit Desmolaize ◽  
Puneet Jaju ◽  
Cornelia Wilhelm ◽  
Ralf Warrass ◽  
...  
Keyword(s):  
Multiplex Pcr ◽  
Pasteurella Multocida ◽  
Macrolide Resistance ◽  
Mannheimia Haemolytica ◽  
23S Rrna ◽  
Type I ◽  
Pcr Assay ◽  
Content Type ◽  
Microbiological Methods ◽  
Tract Infections

ABSTRACTThe bacterial pathogensMannheimia haemolyticaandPasteurella multocidaare major etiological agents in respiratory tract infections of cattle. Although these infections can generally be successfully treated with veterinary macrolide antibiotics, a few recent isolates have shown resistance to these drugs. Macrolide resistance in members of the familyPasteurellaceaeis conferred by combinations of at least three genes:erm(42), which encodes a monomethyltransferase and confers a type I MLSB(macrolide, lincosamide, and streptogramin B) phenotype;msr(E), which encodes a macrolide efflux pump; andmph(E), which encodes a macrolide-inactivating phosphotransferase. Here, we describe a multiplex PCR assay that detects the presence oferm(42),msr(E), andmph(E) and differentiates between these genes. In addition, the assay distinguishesP. multocidafromM. haemolyticaby amplifying distinctive fragments of the 23S rRNA (rrl) genes. Onerrlfragment acts as a general indicator of gammaproteobacterial species and confirms whether the PCR assay has functioned as intended on strains that are negative forerm(42),msr(E), andmph(E). The multiplex system has been tested on more than 40 selected isolates ofP. multocidaandM. haemolyticaand correlated with MICs for the veterinary macrolides tulathromycin and tilmicosin, and the newer compounds gamithromycin and tildipirosin. The multiplex PCR system gives a rapid and robustly accurate determination of macrolide resistance genotypes and bacterial genus, matching results from microbiological methods and whole-genome sequencing.

scholarly journals Neisseria gonorrhoeae Sequence Typing for Antimicrobial Resistance, a Novel Antimicrobial Resistance Multilocus Typing Scheme for Tracking Global Dissemination of N. gonorrhoeae Strains

2017 ◽  
Vol 55 (5) ◽  
pp. 1454-1468 ◽  
Author(s):  
W. Demczuk ◽  
S. Sidhu ◽  
M. Unemo ◽  
D. M. Whiley ◽  
V. G. Allen ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Neisseria Gonorrhoeae ◽  
Dna Sequences ◽  
Diversity Index ◽  
23S Rrna ◽  
Content Type ◽  
Typing Scheme ◽  
Resistance Determinants ◽  
Index Value ◽  
User Friendly

ABSTRACTA curated Web-based user-friendly sequence typing tool based on antimicrobial resistance determinants inNeisseria gonorrhoeaewas developed and is publicly accessible (https://ngstar.canada.ca). TheN. gonorrhoeaeSequence Typing for Antimicrobial Resistance (NG-STAR) molecular typing scheme uses the DNA sequences of 7 genes (penA,mtrR,porB,ponA,gyrA,parC, and 23S rRNA) associated with resistance to β-lactam antimicrobials, macrolides, or fluoroquinolones. NG-STAR uses the entirepenAsequence, combining the historical nomenclature forpenAtypes I to XXXVIII with novel nucleotide sequence designations; the fullmtrRsequence and a portion of its promoter region; portions ofponA,porB,gyrA, andparC; and 23S rRNA sequences. NG-STAR grouped 768 isolates into 139 sequence types (STs) (n= 660) consisting of 29 clonal complexes (CCs) having a maximum of a single-locus variation, and 76 NG-STAR STs (n= 109) were identified as unrelated singletons. NG-STAR had a high Simpson's diversity index value of 96.5% (95% confidence interval [CI] = 0.959 to 0.969). The most common STs were NG-STAR ST-90 (n= 100; 13.0%), ST-42 and ST-91 (n= 45; 5.9%), ST-64 (n= 44; 5.72%), and ST-139 (n= 42; 5.5%). Decreased susceptibility to azithromycin was associated with NG-STAR ST-58, ST-61, ST-64, ST-79, ST-91, and ST-139 (n= 156; 92.3%); decreased susceptibility to cephalosporins was associated with NG-STAR ST-90, ST-91, and ST-97 (n= 162; 94.2%); and ciprofloxacin resistance was associated with NG-STAR ST-26, ST-90, ST-91, ST-97, ST-150, and ST-158 (n= 196; 98.0%). All isolates of NG-STAR ST-42, ST-43, ST-63, ST-81, and ST-160 (n= 106) were susceptible to all four antimicrobials. The standardization of nomenclature associated with antimicrobial resistance determinants through an internationally available database will facilitate the monitoring of the global dissemination of antimicrobial-resistantN. gonorrhoeaestrains.

scholarly journals Fur Represses Adhesion to, Invasion of, and Intracellular Bacterial Community Formation within Bladder Epithelial Cells and Motility in Uropathogenic Escherichia coli

2016 ◽  
Vol 84 (11) ◽  
pp. 3220-3231 ◽  
Author(s):  
Kumiko Kurabayashi ◽  
Tomohiro Agata ◽  
Hirofumi Asano ◽  
Haruyoshi Tomita ◽  
Hidetada Hirakawa
Keyword(s):  
Escherichia Coli ◽  
Epithelial Cells ◽  
Antimicrobial Agents ◽  
Host Cells ◽  
Type I ◽  
Wild Type ◽  
Content Type ◽  
Type I Fimbriae ◽  
Tract Infections

Uropathogenic Escherichia coli (UPEC) is a major pathogen that causes urinary tract infections (UTIs). This bacterium adheres to and invades the host cells in the bladder, where it forms biofilm-like polymicrobial structures termed intracellular bacterial communities (IBCs) that protect UPEC from antimicrobial agents and the host immune systems. Using genetic screening, we found that deletion of the fur gene, which encodes an iron-binding transcriptional repressor for iron uptake systems, elevated the expression of type I fimbriae and motility when UPEC was grown under iron-rich conditions, and it led to an increased number of UPEC cells adhering to and internalized in bladder epithelial cells. Consequently, the IBC colonies that the fur mutant formed in host cells were denser and larger than those formed by the wild-type parent strain. Fur is inactivated under iron-restricted conditions. When iron was depleted from the bacterial cultures, wild-type UPEC adhesion, invasion, and motility increased, similar to the case with the fur mutant. The purified Fur protein bound to regions upstream of fimA and flhD , which encode type I fimbriae and an activator of flagellar expression that contributes to motility, respectively. These results suggest that Fur is a repressor of fimA and flhD and that its repression is abolished under iron-depleted conditions. Based on our in vitro experiments, we conclude that UPEC adhesion, invasion, IBC formation, and motility are suppressed by Fur under iron-rich conditions but derepressed under iron-restricted conditions, such as in patients with UTIs.

scholarly journals Epidemiology and mechanism of drug resistance of Mycoplasma pneumoniae in Beijing, China: A multi-center study

2019 ◽  
Author(s):  
Dong-Xing Guo ◽  
Wen-Juan Hu ◽  
Ran Wei ◽  
Hong Wang ◽  
Bao-Ping Xu ◽  
...  
Keyword(s):  
Mycoplasma Pneumoniae ◽  
Nested Pcr ◽  
Pediatric Patients ◽  
School Age Children ◽  
23S Rrna ◽  
Type I ◽  
School Age ◽  
Broth Microdilution Method ◽  
Tract Infections ◽  
Beijing China

Mycoplasma pneumoniae (M. pneumoniae) is one of the most common causes of community-acquired respiratory tract infections (RTIs). We aimed to investigate the prevalence of M. pneumoniae infection, antibiotic resistance and genetic diversity of M. pneumoniae isolates across multiple centers in Beijing, China. P1 protein was detected by Nested PCR to analyze the occurrence of M. pneumoniae in pediatric patients with RTI. M. pneumoniae isolates were cultured and analyzed by Nested-PCR to determine their genotypes. Broth microdilution method was used to determine the minimum inhibitory concentration (MIC) of antibiotics. Out of 822 children with RTI admitted to 11 hospitals in Beijing, 341 (41.48%) were positive for M. pneumoniae by Nested PCR and 236 (69.21%) samples had mutations in 23S rRNA domain V. The highest proportion of M. pneumoniae positive samples was observed in school-age children (118/190; 62.11%) and in pediatric patients with pneumonia (220/389; 56.56%). Out of 341 M. pneumoniae positive samples, 99 (12.04%) isolates were successfully cultured and the MIC values were determined for 65 M. pneumoniae strains. Out of these, 57 (87.69%) strains were resistant to macrolides, and all 65 strains were sensitive to tetracyclines or quinolones. M. pneumoniae P1 type I and P1 type II strains were found in 57/65 (87.69%) and 8/65 (12.31%) of cultured isolates, respectively. Overall, we demonstrated a high prevalence of M. pneumoniae infection and high macrolide resistance of M. pneumoniae strains in Beijing. School-age children were more susceptible to M. pneumoniae, particularly the children with pneumonia. Thus, establishment of a systematic surveillance program to fully understand the epidemiology of M. pneumoniae is critical for the standardized use of antibiotics in China.

scholarly journals Coinfection with Blood-Stage Plasmodium Promotes Systemic Type I Interferon Production during Pneumovirus Infection but Impairs Inflammation and Viral Control in the Lung

2015 ◽  
Vol 22 (5) ◽  
pp. 477-483 ◽  
Author(s):  
Chelsea L. Edwards ◽  
Vivian Zhang ◽  
Rhiannon B. Werder ◽  
Shannon E. Best ◽  
Ismail Sebina ◽  
...  
Keyword(s):  
Young Children ◽  
Inflammatory Responses ◽  
Blood Stage ◽  
Sub Saharan Africa ◽  
Type I ◽  
Viral Control ◽  
Viral Pathogen ◽  
Content Type ◽  
Viral Dissemination ◽  
Tract Infections

ABSTRACTAcute lower respiratory tract infections (ALRTI) are the leading cause of global childhood mortality, with human respiratory syncytial virus (hRSV) being a major cause of viral ALRTI in young children worldwide. In sub-Saharan Africa, many young children experience severe illnesses due to hRSV orPlasmodiuminfection. Although the incidence of malaria in this region has decreased in recent years, there remains a significant opportunity for coinfection. Recent data show that febrile young children infected withPlasmodiumare often concurrently infected with respiratory viral pathogens but are less likely to suffer from pneumonia than are non-Plasmodium-infected children. Here, we hypothesized that blood-stagePlasmodiuminfection modulates pulmonary inflammatory responses to a viral pathogen but does not aid its control in the lung. To test this, we established a novel coinfection model in which mice were simultaneously infected with pneumovirus of mice (PVM) (to model hRSV) and blood-stagePlasmodium chabaudi chabaudiAS (PcAS) parasites. We found thatPcAS infection was unaffected by coinfection with PVM. In contrast, PVM-associated weight loss, pulmonary cytokine responses, and immune cell recruitment to the airways were substantially reduced by coinfection withPcAS. Importantly,PcAS coinfection facilitated greater viral dissemination throughout the lung. AlthoughPlasmodiumcoinfection induced low levels of systemic interleukin-10 (IL-10), this regulatory cytokine played no role in the modulation of lung inflammation or viral dissemination. Instead, we found thatPlasmodiumcoinfection drove an early systemic beta interferon (IFN-β) response. Therefore, we propose that blood-stagePlasmodiumcoinfection may exacerbate viral dissemination and impair inflammation in the lung by dysregulating type I IFN-dependent responses to respiratory viruses.

scholarly journals FNR Regulates Expression of Important Virulence Factors Contributing to Pathogenicity of Uropathogenic Escherichia coli

2014 ◽  
Vol 82 (12) ◽  
pp. 5086-5098 ◽  
Author(s):  
Nicolle L. Barbieri ◽  
Bryon Nicholson ◽  
Ashraf Hussein ◽  
Wentong Cai ◽  
Yvonne M. Wannemuehler ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Bacterial Infections ◽  
Uropathogenic Escherichia Coli ◽  
Type I ◽  
Wild Type ◽  
Global Regulator ◽  
Content Type ◽  
Tract Infections

ABSTRACTUropathogenicEscherichia coli(UPEC) is responsible for the majority of urinary tract infections (UTIs), which are some of the world's most common bacterial infections of humans. Here, we examined the role of FNR (fumarate andnitratereduction), a well-known global regulator, in the pathogenesis of UPEC infections. We constructed anfnrdeletion mutant of UPEC CFT073 and compared it to the wild type for changes in virulence, adherence, invasion, and expression of key virulence factors. Compared to the wild type, thefnrmutant was highly attenuated in the mouse model of human UTI and showed severe defects in adherence to and invasion of bladder and kidney epithelial cells. Our results showed that FNR regulates motility and multiple virulence factors, including expression of type I and P fimbriae, modulation of hemolysin expression, and expression of a novel pathogenicity island involved in α-ketoglutarate metabolism under anaerobic conditions. Our results demonstrate that FNR is a key global regulator of UPEC virulence and controls expression of important virulence factors that contribute to UPEC pathogenicity.

scholarly journals Isolation of Bacterial causes of Respiratory Infections in Calves in Smallholder farms in and around Gonder Town, Ethiopia

2020 ◽  
Author(s):  
Tefera Manaye ◽  
Pawlos Wasihun Asnake ◽  
Ashebr Abraha ◽  
Tsegaw Fentie
Keyword(s):  
Risk Factors ◽  
Respiratory Disease ◽  
Pasteurella Multocida ◽  
Respiratory Infections ◽  
Mannheimia Haemolytica ◽  
Nasopharyngeal Swab ◽  
Respiratory Pathogens ◽  
Isolation Rate ◽  
Cross Sectional ◽  
Tract Infections

Abstract Background: Bovine respiratory disease (BRD) is considered as the major cause of severe respiratory tract infections in calves. Pasteurellosis is a multifactorial respiratory disease, which mainly affect calves within four weeks of weaning. A cross-sectional study was conducted from October 2017 to April 2018 in and around Gondar town, Amhara Regional State, North West of Ethiopia. The aim of the study was to isolate Mannheimia and Pasteurella species from calves up to six months old, and to assess the associated risk factors with the occurrence of respiratory disease. Sex, age (< 16 weeks and > 16 weeks), body condition status (poor, medium, good), breed (local and cross breed), livelihood (mixed crop and urban), farming systems (semi intensive and intensive), herd size (small medium, and large), maternity pens (present or absent), and method of colostrum feedings (hand bucket and suckling) were the examined risk factors.Results: A total of 84 nasopharyngeal swab samples were collected from calves with any signs of illness related to pasteurellosis. The overall isolation rate of the respiratory pathogens was 64/84 (76.2%) (95% CI=65.7-84.8), with 46.4% of Mannheimia haemolytica and 28.8% Pasteurella multocida isolates. The distribution of pathogens was statistically higher (P< 0.001) in calves with respiratory problems (93.6%; 95% CI= 82.5-98.7) compared to those with no symptoms of respiratory illness (54.1%; 95% CI= 36.9-70.5). Among the examined risk factors age, sex, breed, farming system were found to be potential risk factors and significantly associated with Pasteurella infection of calves (p<0.05). The higher isolation rate of Mannheimia haemolytica indicated that it is the major cause of respiratory disease in the study area.Conclusion: The present finding revealed that pasteurellosis is one of the major diseases of calves in the study area in which M. haemolytica and P. multocida were found to be commonly involved in respiratory infections. Improved farm management including timely feeding of colostrum, appropriate hygiene of the calf house and training of farmers is recommended to prevent and control of respiratory diseases in the study area.

scholarly journals Prevalence, genotyping and macrolide resistance of Mycoplasma pneumoniae among isolates of patients with respiratory tract infections, Central Slovenia, 2006 to 2014

2015 ◽  
Vol 20 (37) ◽  
Author(s):  
Rok Kogoj ◽  
Tatjana Mrvic ◽  
Marina Praprotnik ◽  
Darja Kese
Keyword(s):  
Respiratory Tract ◽  
Mycoplasma Pneumoniae ◽  
Respiratory Tract Infections ◽  
Geographic Area ◽  
Macrolide Resistance ◽  
23S Rrna ◽  
Rrna Gene ◽  
Type I ◽  
Type Ii ◽  
Tract Infections

In this retrospective study we employed real-time polymerase chain reaction (PCR) to analyse the occurrence of Mycoplasma pneumoniae among upper and lower respiratory tract infections (RTI) in the Central Region of Slovenia between January 2006 and December 2014. We also used a culture and pyrosequencing approach to genotype strains and infer their potential macrolide resistance. Of a total 9,431 tested samples from in- and out-patient with RTI, 1,255 (13%) were found to be positive by M. pneumoniae PCR. The proportion of positive samples was 19% (947/5,092) among children (?16 years-old) and 7% (308/4,339) among adults (>16 years-old). Overall, among those PCR tested, the highest proportions of M. pneumoniae infections during the study period were observed in 2010 and 2014. In these two years, 18% (218/1,237) and 25% (721/2,844) of samples were positive respectively, indicating epidemic periods. From the 1,255 M. pneumoniae PCR-positive samples, 783 (614 from paediatric and 169 from adult patients) were successfully cultured. Of these, 40% (312/783) were constituted of strains belonging to the P1 type II genomic group, while 60% (469/783) contained strains of the P1 type I group. Two isolates comprised both P1 type I and II strains. Results of a genotype analysis by year, showed that the dominant M. pneumoniae P1 type during the 2010 epidemic was P1 type II (82% of isolates; 81/99), which was replaced by P1 type I in the 2014 epidemic (75%; 384/510). This observation could indicate that the two epidemics may have been driven by a type shift phenomenon, although both types remained present in the studied population during the assessed period of time. Only 1% of strains (7/783) were found to harbour an A2063G mutation in the 23S rRNA gene, which confers macrolide resistance, suggesting that the occurrence of M. pneumoniae macrolide resistance still seems to be sporadic in our geographic area.

scholarly journals Transferable Multidrug-Resistance Plasmid Carrying a Novel Macrolide-Clindamycin Resistance Gene, erm(50), in Cutibacterium acnes

2019 ◽  
Vol 64 (3) ◽  
Author(s):  
Sae Aoki ◽  
Keisuke Nakase ◽  
Hidemasa Nakaminami ◽  
Takeaki Wajima ◽  
Nobukazu Hayashi ◽  
...  
Keyword(s):  
Resistance Gene ◽  
Acne Vulgaris ◽  
Tetracycline Resistance ◽  
23S Rrna ◽  
The Novel ◽  
Content Type ◽  
Resistance Determinants ◽  
Cutibacterium Acnes ◽  
High Level ◽  
Rrna Mutation

ABSTRACT Antimicrobial-resistant Cutibacterium acnes strains have emerged and disseminated throughout the world. The 23S rRNA mutation and erm(X) gene are known as the major resistance determinants of macrolides and clindamycin in C. acnes. We isolated eight high-level macrolide-clindamycin-resistant C. acnes strains with no known resistance determinants, such as 23S rRNA mutation and erm(X), from different acne patients in 2008 between 2013 and 2015. The aim of this study was to identify the novel mechanisms of resistance in C. acnes. Whole-genome sequencing revealed the existence of a plasmid DNA, denoted pTZC1 (length, 31,440 bp), carrying the novel macrolide-clindamycin resistance gene erm(50) and tetracycline resistance gene tet(W). pTZC1 was detected in all C. acnes isolates (eight strains) exhibiting high-level macrolide-clindamycin resistance, with no known resistance determinants (MIC of clarithromycin, ≥256 μg/ml; clindamycin, ≥256 μg/ml). Transconjugation experiments demonstrated that the pTZC1 was horizontally transferred among C. acnes strains and conferred resistance to macrolides, clindamycin, and tetracyclines. Our data showed, for the first time, the existence of a transferable multidrug-resistant plasmid in C. acnes. Increased prevalence of this plasmid will be a great threat to antimicrobial therapy for acne vulgaris.

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