Quintuplex PCR to Detect Antibiotic Resistance Genes in Streptococcus pneumoniae

Introduction: Streptococcus pneumoniae is an important bacterial pathogen, causing respiratory infection. Penicillin resistance in S. pneumoniae is associated with alterations in the penicillin binding proteins, while resistance to macrolides is conferred either by the modification of the ribosomal target site or efflux mechanism. This study aimed to characterize S. pneumoniae and its antibiotic resistance genes using 2 sets of multiplex PCRs. Methods: A quintuplex and triplex PCR was used to characterize the pbp1A, ermB, gyrA, ply, and the mefE genes. Fifty-eight penicillin sensitive strains (PSSP), 36 penicillin intermediate strains (PISP) and 26 penicillin resistance strains (PRSP) were used. Results: Alteration in pbp1A was only observed in PISP and PRSP strains, while PCR amplification of the ermB or mefE was observed only in strains with reduced susceptibility to erythromycin. The assay was found to be sensitive as simulated blood cultures showed the lowest level of detection to be 10cfu. Conclusions: As predicted, the assay was able to differentiate penicillin susceptible from the non-susceptible strains based on the detection of the pbp1A gene, which correlated with the MIC value of the strains.

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Phenotypic and genotypic evaluation of antibiotic resistance and molecular characterization of Streptococcus species isolated from hospital cockroaches

10.21203/rs.3.rs-23316/v1 ◽

2020 ◽

Author(s):

Mohammad Chehelgerdi ◽

Reza Ranjbar

Keyword(s):

Antibiotic Resistance ◽

Virulence Factors ◽

Resistance Genes ◽

Bacterial Culture ◽

Antibiotic Resistance Genes ◽

Pcr Amplification ◽

Hospital Environment ◽

Streptococcus Species ◽

Antibiotic Resistance Properties

Abstract Background The present investigation aimed to assess the antibiotic resistance properties and distribution of virulence factors in the Streptococcus spp. isolated from hospital cockroaches. Methods Six-hundred and sixty cockroach samples were collected. Cockroaches were vigorously washed with normal saline, and the achieved saline was used for bacterial culture. Isolated Streptococcus spp. were subjected to disk diffusion as well as PCR amplification of virulence factors and antibiotic resistance genes. Results Prevalence of S. pyogenes, S. agalactiae and S. pneumonia was 4.82%, 1.66% and 6.96%, respectively. The highest prevalence of S. pyogenes, S. agalactiae and S. pneumonia were found in oriental (5.71%), oriental (2.85%) and American (7.71%) cockroaches, respectively. Cfb (53.93%), cyl (52.8%), scaa (51.68%) and glna (50.56%) were the most commonly detected streptococcal virulence factors. Pbp2b (71.91%), pbp2 × (58.42%), mefA (46.06%), ermB (46.06%) and tetM (46.06%) were the most commonly detected antibiotic resistance genes. Streptococcal spp. exhibited the highest prevalence of resistance against tetracycline (80.89%), trimethoprim (65.16%), and penicillin (56.17%). Conclusion To the best of our knowledge, this is the first prevalence report of virulence factors and antibiotic resistance genes in the Streptococcal spp. isolated from American, German and oriental hospital cockroaches. Findings recommended a certain role for cockroaches in the transmission of nosocomial infections and particularly those caused by virulent and resistant Streptococcus spp. in the hospital environment.

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Distribution of Beta-Lactamase Producing Gram-Negative Bacterial Isolates in Isabela River of Santo Domingo, Dominican Republic

Frontiers in Microbiology ◽

10.3389/fmicb.2020.519169 ◽

2021 ◽

Vol 11 ◽

Author(s):

Víctor V. Calderón ◽

Roberto Bonnelly ◽

Camila Del Rosario ◽

Albert Duarte ◽

Rafael Baraúna ◽

...

Keyword(s):

Antibiotic Resistance ◽

Resistance Genes ◽

Rural Areas ◽

Clinical Importance ◽

Antibiotic Resistance Genes ◽

Pcr Amplification ◽

Resistant Bacteria ◽

Beta Lactamase ◽

Bacterial Isolates ◽

Santo Domingo

Bacteria carrying antibiotic resistance genes (ARGs) are naturally prevalent in lotic ecosystems such as rivers. Their ability to spread in anthropogenic waters could lead to the emergence of multidrug-resistant bacteria of clinical importance. For this study, three regions of the Isabela river, an important urban river in the city of Santo Domingo, were evaluated for the presence of ARGs. The Isabela river is surrounded by communities that do not have access to proper sewage systems; furthermore, water from this river is consumed daily for many activities, including recreation and sanitation. To assess the state of antibiotic resistance dissemination in the Isabela river, nine samples were collected from these three bluedistinct sites in June 2019 and isolates obtained from these sites were selected based on resistance to beta-lactams. Physico-chemical and microbiological parameters were in accordance with the Dominican legislation. Matrix-assisted laser desorption ionization-time of flight mass spectrometry analyses of ribosomal protein composition revealed a total of 8 different genera. Most common genera were as follows: Acinetobacter (44.6%) and Escherichia (18%). Twenty clinically important bacterial isolates were identified from urban regions of the river; these belonged to genera Escherichia (n = 9), Acinetobacter (n = 8), Enterobacter (n = 2), and Klebsiella (n = 1). Clinically important multi-resistant isolates were not obtained from rural areas. Fifteen isolates were selected for genome sequencing and analysis. Most isolates were resistant to at least three different families of antibiotics. Among beta-lactamase genes encountered, we found the presence of blaTEM, blaOXA, blaSHV, and blaKPC through both deep sequencing and PCR amplification. Bacteria found from genus Klebsiella and Enterobacter demonstrated ample repertoire of antibiotic resistance genes, including resistance from a family of last resort antibiotics reserved for dire infections: carbapenems. Some of the alleles found were KPC-3, OXA-1, OXA-72, OXA-132, CTX-M-55, CTX-M-15, and TEM-1.

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