scholarly journals Resistance behaviour of inducible clindamycin-resistant staphylococci from clinical samples and aquatic environments

2014 ◽  
Vol 63 (11) ◽  
pp. 1446-1453 ◽  
Author(s):  
Stefanie Heß ◽  
Claudia Gallert
Keyword(s):  
Species Diversity ◽  
Resistance Genes ◽  
Cross Resistance ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Aquatic Environments ◽  
Environmental Isolates ◽  
Inducible Clindamycin Resistance ◽  
Genes Encoding ◽  
Resistance Patterns

In this study, the species diversity of staphylococci with inducible resistance to macrolides, lincosamides and streptogramin B (MLSB) isolated from clinical samples, sewage and river water was investigated. Inducible clindamycin resistance was tested using a D-test and macrodilution assays. Inducible cross-resistance (iMLSB phenotype) was examined by PCR of erm gene classes A, B, C, F, G, Q, T and 43. Although ermC was the most frequently detected resistance gene in iMLSB phenotypes of environmental staphylococci (61.2 %), resistance genes encoding iMLSB were more diverse than in staphylococci from hospital samples. In 22.4 % of iMLSB staphylococci from aquatic environments, none of the eight tested erm genes was found. Those isolates and erm43-expressing Staphylococcus lentus displayed low erythromycin MICs (3–16 µg ml−1) compared with ermC-positive environmental staphylococci (≥256 µg ml−1). In contrast to clinical isolates with clearly defined resistance behaviour, resistance patterns against MLSB and MICs for clindamycin of environmental isolates were more diverse. Although the abundance of iMLSB staphylococci in the aquatic environment was lower than in staphylococci from hospital samples, the diversity of resistance genes encoding this phenotype seemed to be higher. Oleandomycin is the best marker to correlate iMLSB phenotype and the respective erm gene. The phenotypical behaviour of environmental isolates may differ from the resistance pattern of clinical iMLSB staphylococci expressing ermA or ermC, and this should be considered for successful treatment of infections.

scholarly journals Coexistence of aminoglycoside resistance genes in CTX-M-producing isolates of Klebsiella pneumoniae in Bushehr province, Iran

2021 ◽  
Author(s):  
Behrouz Latifi ◽  
Saeed Tajbakhsh ◽  
Leila Ahadi ◽  
Forough Yousefi
Keyword(s):  
Klebsiella Pneumoniae ◽  
Resistance Genes ◽  
Confirmatory Test ◽  
M Gene ◽  
Aminoglycoside Resistance ◽  
Genetic Groups ◽  
Genes Encoding ◽  
Resistance Patterns ◽  
Aminoglycoside Resistance Genes ◽  
Antibiotic Resistance Patterns

Background and Objectives: Increasing the rate of extended-spectrum β-lactamase (ESBL)-producing Klebsiella pneumoniae has given rise to a major healthcare issue in clinical settings over the past few years. Treatment of these strains is hardly effective since the plasmid encoding ESBL may also carry other resistance genes including aminoglycosides. The current study aimed to evaluate the prevalence of ESBL-producing K. pneumoniae and investigate the coexistence of Cefoxitamase-Munich (bla ) with aminoglycoside-modifying enzyme (AME) genes, aac(3)IIa as well as aac(6′)Ib, in CTX‑M‑producing K. pneumoniae isolated from patients in Bushehr province, Iran. Materials and Methods: A total of 212 K. pneumoniae isolates were collected and confirmed using polymerase chain re‑ action (PCR) of the malate dehydrogenase gene. Isolates were screened for production of ESBL. Phenotypic confirmatory test was performed using combined disk test. The genes encoding CTX-M groups and AME genes, aac(3)IIa and aac(6′)Ib, were investigated by PCR. Results: The ESBL phenotype was detected in 56 (26.4%) K. pneumoniae isolates. Moreover, 83.9% of ESBL-producing isolates carried the genes for CTX-M type β-lactamases, which were distributed into the two genetic groups of CTX-M-1 (97.8%)- and CTX-M-2 (2.1%)-related enzymes. Notably, among K. pneumoniae isolates containing the blaCTX‑M gene, 68.08% of isolates harbored AME genes. In addition, the coexistence of bla in 46.8% of CTX-M-producing K. pneumoniae isolates. Conclusion: This study provides evidence of a high prevalence of AME genes in CTX-M- producing K. pneumoniae iso‑ lates; therefore, in the initial empirical treatment of infections caused by ESBL-KP in regions with such antibiotic resistance patterns, aminoglycoside combination therapy should be undertaken carefully.

Antibiotic resistance patterns of Pseudomonas spp. isolated from faecal wastes in the environment and contaminated surface water

2020 ◽  
Vol 96 (2) ◽  
Author(s):  
Mathilde Camiade ◽  
Josselin Bodilis ◽  
Naouel Chaftar ◽  
Wassila Riah-Anglet ◽  
Johan Gardères ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Enteric Bacteria ◽  
Resistance Pattern ◽  
Pathogenic Species ◽  
Pseudomonas Species ◽  
Class 1 ◽  
Resistance Patterns ◽  
Faecal Bacteria ◽  
Antibiotic Resistance Patterns

ABSTRACT The Pseudomonas genus, which includes environmental and pathogenic species, is known to present antibiotic resistances, and can receive resistance genes from multi-resistant enteric bacteria released into the environment via faecal rejects. This study was aimed to investigate the resistome of Pseudomonas populations that have been in contact with these faecal bacteria. Thus, faecal discharges originating from human or cattle were sampled (from 12 points and two sampling campaigns) and 41 Pseudomonas species identified (316 isolates studied). The resistance phenotype to 25 antibiotics was determined in all isolates, and we propose a specific antibiotic resistance pattern for 14 species (from 2 to 9 resistances). None showed resistance to aminoglycosides, tetracycline, or polymyxins. Four species carried a very low number of resistances, with none to β-lactams. Interestingly, we observed the absence of the transcriptional activator soxR gene in these four species. No plasmid transfer was highlighted by conjugation assays, and a few class 1 but no class 2 integrons were detected in strains that may have received resistance genes from Enterobacteria. These results imply that the contribution of the Pseudomonas genus to the resistome of an ecosystem first depends on the structure of the Pseudomonas populations, as they may have very different resistance profiles.

scholarly journals Identification of powdery mildew resistance genes in Polish common oat (Avena sativa L.) cultivars using host-pathogen tests

2012 ◽  
Vol 65 (3) ◽  
pp. 63-68 ◽  
Author(s):  
Sylwia Okoń
Keyword(s):  
Powdery Mildew ◽  
Resistance Genes ◽  
Powdery Mildew Resistance ◽  
Resistance Pattern ◽  
Mildew Resistance ◽  
Differential Set ◽  
Host Pathogen ◽  
Resistance Patterns ◽  
Breeding Programmes ◽  
New Gene

The aim of the present study was to characterize and identify powdery mildew resistance genes in Polish common oat cultivars using host-pathogen tests. A differential set of six <em>Blumeria graminis </em>f.sp<em>. avenae </em>isolates virulent or avirulent to four cultivars and one line that has known resistance to powdery mildew were used. Among the investigated cultivars, only four of them (13.3%) had resistance patterns similar to genotypes belonging to the differential set. The resistance of OMR group 1 was found in the cultivar &lsquo;Dragon&rsquo;, while that of OMR2 in the cultivar &lsquo;Skrzat&rsquo;. The cultivars &lsquo;Deresz&rsquo; and &lsquo;Hetman&rsquo; showed a resistance pattern that corresponded with OMR group 3. The resistance corresponding to OMR4 was not found, which suggests that until now this gene has not been used in Polish oat breeding programmes. The cultivar &lsquo;Canyon&rsquo; had a different pat- tern of resistance than the genotypes that have already known OMR genes, which indicates that the resistance of this cultivar is determined by a new gene or a combination of known genes.

Prevalence of Genes Encoding Aminoglycoside-Modifying Enzymes and armA among Acinetobacter baumannii Clinical Isolates in Alexandria, Egypt

2021 ◽  
Vol 21 ◽  
Author(s):  
Amel ELsheredy ◽  
Zainab Yousif ◽  
Ebtesam Elghazzawi ◽  
Ahmed Elmenshawy ◽  
Abeer Ghazal
Keyword(s):  
Acinetobacter Baumannii ◽  
Resistance Genes ◽  
Antimicrobial Agents ◽  
Clinical Isolates ◽  
Aminoglycoside Resistance ◽  
High Propensity ◽  
Genes Encoding ◽  
Resistance Patterns ◽  
Aminoglycoside Resistance Genes ◽  
High Level

Introduction: Acinetobacter baumannii (A.baumannii ) is a ubiquitous pathogen responsible for serious infections in hospitalized patients with a high propensity to develop resistance to antimicrobial agents. The study aimed to determine the antimicrobial resistance patterns and the prevalence of aminoglycoside resistance genes among A. baumannii clinical isolates from patients in different intensive care units (ICUs) in Alexandria, Egypt. Methods: A total of 100 A. baumannii isolates collected from ICU patients were confirmed as A. baumannii by VITEK 2 and the presence of the blaOXA-51 gene has been reported. Antimicrobial susceptibility testing was performed and Multiplex PCR was done for the detection of aminoglycoside resistance genes. Results: Most of the isolates (82%) were resistant to all tested aminoglycosides; resistance was higher for kanamycin and neomycin, followed by amikacin. The predominant AMEs were aphA6 and aphA1 in 86% and 67% of the isolates, respectively; aacA4 and aacC1 were detected in 37% and 8%, respectively, while aadA1 and aadB were present in 34% and 4%, respectively. Furthermore, armA gene was detected in 83% of the isolates. Conclusion: The results of this study revealed a high level carriage of armA and AMEs which limit the usage of aminoglycoside as a treatment option for A. baumannii and makes treatment extremely difficult.

scholarly journals Patterns of Constitutive and Inducible Clindamycin Resistance in Staphylococcus aureus Isolated from Clinical Samples by D-test Method, Shiraz, Southwest of Iran

2014 ◽  
Vol 3 (4) ◽  
pp. 216-21
Author(s):  
Mohammad Motamedifar ◽  
Hadi Seddigh Ebrahim Sarai ◽  
Davood Mansury
Keyword(s):  
Staphylococcus Aureus ◽  
Medical Center ◽  
Cross Sectional Study ◽  
Test Method ◽  
Teaching Hospitals ◽  
Clinical Samples ◽  
Cross Sectional ◽  
Inducible Clindamycin Resistance ◽  
Resistance Patterns ◽  
Southwest Of Iran

Background: Macrolides, Lincosamides and type B Streptogramins (MLSB) are commonly used for the treatment of Staphylococcal infections. Inducible MLSB resistance (iMLSB) cannot be identified by standard methods of antibiotic susceptibility testing. D-test appears to be a reliable indicator of iMLSB strains. The aim of this study was to determine the prevalence of Clindamycin resistance phenotypes in Staphylococcus aureus (S.aureus) isolated from clinical samples in Shiraz, southwest of Iran.Materials and Methods: This cross-sectional study was performed on a total of 302 S. aureus isolates which were collected from two teaching hospitals in Shiraz during 2012. Methicillin resistant Staphylococcus aureus (MRSA) were screened based on their resistance to 30μg Cefoxitin disk. 168 Methicillin-sensitive Staphylococcus aureus (MSSA) and 134 MRSA isolates were tested in this study. The isolates were tested for susceptibility to Clindamycin (2 µg) and Erythromycin (15 µg) by Clinical and Laboratory Standards Institute (CLSI) recommended disk diffusion test.Results: Of 302 collected S. aureus isolates, 134 (44.4%) were MRSA and 168 (55.6%) were MSSA. Inducible MLSB resistance was observed in 10.4% of all recovered MRSA and 3% of all MSSA isolates. The majority of MRSA isolates (77.6%) constituted MLSB phenotype (cMLSB); this phenotype was seen in 4.1% of our tested MSSA isolates. Finally, 12.0% of MRSA isolates and 89.9% of MSSA showed sensitivity to both Erythromycin and Clindamycin.Conclusion: Different resistance patterns in hospitals indicated that performing routine D-test for S. aureus infections is highly recommended for each medical center. [GMJ. 2014;3(4):216-21]

Phenotypic characterization and Molecular detection of Inducible and Constitutive Clindamycin resistance among Staphylococcus aureus isolates in a Tertiary Care Hospital

2021 ◽  
pp. 3799-3804
Author(s):  
Mahalakshmi G. ◽  
Neelusree P. ◽  
Kalyani M.
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Tertiary Care ◽  
Phenotypic Characterization ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Care Hospital ◽  
Methicillin Resistant ◽  
Inducible Clindamycin Resistance ◽  
Significant Difference

Background: Staphylococcus aureus is Gram positive cocci. The pyogenic bacteria which is responsible for a variety of diseases that ranges in severity from mild skin and soft tissue infections to life-threatening conditions such as endocarditis, pneumonia, and sepsis. There is a scenario of increasing Methicillin-resistant Staphylococcus aureus (MRSA) infections, the macrolide-lincosamide-streptogramin B (MLSB) group of antibiotics they have different structure with same mechanism of action which serves as one good alternative. There is a frequency of increasing Methicillin Resistant Staphylococcus aureus (MRSA) infections and their change in antimicrobial resistance pattern. There is a concern about use of this antibiotic in the presence of Erythromycin resistance because of the possibility of inducible resistance among the members of Macrolide, lincosamide, Strepto-gramin B (MLSB) group. The invitro resistance exhibited by Staphylococcus aureus to erythromycin, Clindamycin, and other drugs of MLSB groups is due to the expression of ribosomal methylases(erm) genes. The detection of inducible Clindamycin resistance can limit the effectiveness of these drugs. Objective of the study: To isolate of Staphylococcus aureus from various clinical samples to differentiate between Methicillin resistant Staphylococcus aureus (MRSA) and Methicillin sensitive Staphylococcus aureus (MSSA) by conventional methods. To detect inducible and constitutive Clindamycin resistance in Staphylococcus aureus isolates by D test. To detect ermA gene responsible for resistance by PCR. Methodology: This cross sectional study was done for a period of six months. Totally 106 Staphylococcus aureus isolates was obtained various clinical samples were processed using standard guidelines. Result: From the 106 isolates of Staphylococcus aureus 67(63.3%) were MSSA and 39(36.7%) were MRSA. D-test was positive in n=9 of the n=21 MRSA and n=17 of the n=85 MSSA, which denotes inducible Clindamycin resistance. N- 9 of MRSA and n=13(22%) of MSSA showed Constitutional Clindamycin resistance. The statistics show that there is a significant Difference in constitutive resistance between MRSA and MSSA. In India ermA gene is most prevalent, out of 22 d-test positive n=13 ermA gene were detected (n=3-MRSA and n=10-MSSA) by using conventional PCR. Conclusion: The MLSB family of antibiotics is one such alternative and CD is preferred. Clinical microbiology laboratories should report inducible Clindamycin resistance in Staphylococcus aureus and D-test can be used as a simple, auxiliary and reliable method to Delineate inducible and constitutive Clindamycin resistance in routine clinical laboratories.

scholarly journals Detection of resistance genes and evaluation of water quality at zoo lakes in Brazil

2016 ◽  
Vol 46 (5) ◽  
pp. 860-866 ◽  
Author(s):  
Ana Carolina Silva de Faria ◽  
Isabela de Godoy ◽  
Anderson Aparecido Amorim Sanches ◽  
Gabriela Accardi Iglesias ◽  
Stefhano Luiz Candido ◽  
...  
Keyword(s):  
Water Quality ◽  
Resistance Genes ◽  
Animal Health ◽  
Antibiotic Resistance Genes ◽  
Aquatic Environments ◽  
Urban Sewage ◽  
Quality Of Water ◽  
Genes Encoding ◽  
Multiple Antibiotics

ABSTRACT: The investigation of the presence of antibiotic-resistance genes in aquatic environments is important to identify possible reservoirs of resistant microorganisms that could be a threat to human and animal health. The aims of this study were to analyze the presence of genes conferring resistance to antimicrobials in the aquatic environment and to assess the quality of water in zoo lakes. Results showed a pattern of genes conferring resistance to multiple antibiotics and turbidity, which was expected to be due to the presence of contaminants. The most frequent genes were sul I and sul II (sulfonamides), which were present in all the lakes, followed by genes encoding β-lactamases such as blaPSE I (77.8%) and ampC (66.7%). However, tet(K), tet(M), and ermC genes were not detected. There was a positive correlation between the number of Enterobacteriaceae and resistance genes. In conclusion, the source of contamination of all lakes was probably the neighboring urban sewage or wastewater that increased the frequency of the total coliforms and resistance genes, which in turn posed a threat to the conservation of the animal life inhabiting the zoo.

scholarly journals Application of Multiplex PCR for the Identification of Oxacillinase Genes and Determination of Antibiotic Resistance Pattern in Environmental Isolates of Acinetobacter baumannii in ICU

2021 ◽  
Vol 8 (3) ◽  
pp. 89-93
Author(s):  
Anahita Farajzadeh ◽  
Mohsen Mirzaee ◽  
Shahram Nanekarani ◽  
Reza Yari
Keyword(s):  
Acinetobacter Baumannii ◽  
Multiplex Pcr ◽  
Polymyxin B ◽  
Resistance Pattern ◽  
Rrna Gene ◽  
Environmental Isolates ◽  
Biochemical Tests ◽  
Cross Sectional ◽  
Significance Level ◽  
Genes Encoding

Background: Acinetobacter baumannii is a common cause of nosocomial infections. A prominent feature of these bacteria is resistance to carbapenems. This study aimed to identify OXA genes encoding oxacillinase in Acinetobacter baumannii isolates. Methods: This cross-sectional descriptive study was performed on 25 environmental A. baumannii isolates collected from ICU over 8 months. Definitive identification of isolates was performed by biochemical tests and polymerase chain reaction (PCR) of 16s rRNA gene. Antibiotic susceptibility testing was performed on Müller-Hinton agar medium by disk diffusion and E-test. Antibiogram and multiplex PCR data of beta-lactamase genes were collected and analyzed at a significance level of P<0.05 using SPSS 22.0. Results: Except for one isolate, all isolates (96%) were sensitive to polymyxin B and 80% of isolates were sensitive to oxacillin. All isolates were sensitive to meropenem, ampicillin/sulbactam, gentamicin, amikacin, piperacillin, and carbenicillin. The results showed that 25 isolates (100%) had OXA-51 gene, 21 isolates (84%) had OXA-58 gene, one isolate (4%) had OXA-24 gene, and none of the isolates contained OXA-23 gene. Only isolate No.10 had three oxacillinase genes simultaneously and it was resistant to oxacillin, polymyxin B, and cephalothin. Conclusions: The study showed that environmental isolates of ICU do not have pathogenic genes present in the clinical isolates, and how these genes are transferred to the peripheral isolates is an important point that should be studied. Identification of genes encoding carbapenem resistance may help to understand the mechanisms of resistance transfer in A. baumannii. The lack of the OXA-23 gene plays an important role in the susceptibility of isolates to antibiotics and non-emergence of resistant strains.

scholarly journals Molecular Analysis of KPC and GES Beta-Lactamase Genes in Clinical Isolates of Klebsiella pneumoniae by PCR Method

2021 ◽  
Vol 8 (2) ◽  
pp. 01-08
Author(s):  
Zohreh Saltanatpour ◽  
Marzieh Saremi ◽  
Leila Saremi ◽  
Sepideh Babaniamansour ◽  
Razieh Nazari
Keyword(s):  
Antibiotic Resistance ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Klebsiella Pneumonia ◽  
Carbapenem Resistant ◽  
Appropriate Treatment ◽  
Resistance Patterns ◽  
Pcr Method ◽  
Resistant Strains ◽  
Antibiotic Resistance Patterns

Background: Carbapenem-resistant Klebsiella pneumonia (K. pneumoniae) has been recently identified as the major class of pathogens and the treatment became the biggest challenge in this bacterium. We assessed the antibiotic resistance patterns of K. pneumoniae, the frequency of resistant strains to imipenem, meropenem, and ertapenem, and the frequency of K. pneumoniae carbapenemases (KPC), and Guiana-Extended-Spectrum (GES) metallo-β-lactamase genes. Methods: The phenotypes of 200 strains of K. pneumonia, collected from 650 clinical samples, were isolating and identified in Qom, Iran. The antibiotic resistance pattern of the strains was analyzed against different antibiotics. The imipenem, meropenem, and ertapenem-resistant strains, were isolated and the frequency of KPC and GES genes were evaluated. Results: K. pneumoniae strains had different resistance patterns against various antibiotics. The isolated strains with the highest and lowest antibiotic resistance were related to ampicillin, and meropenem, respectively. Investigation of the KPC and GES β lactamase showed that none of 48 imipenem, meropenem, and ertapenem-resistance isolates had the KPC gene. In addition, the GES gene was detected in 3(2.7%) of 110 ceftazidime-resistant specimens. Conclusions: Carbapenem is useful in the treatment of K. pneumoniae infections. Due to the importance of the mechanisms of resistance is by β-lactamase genes, investigating the prevalence of β-lactamase genes can help to increase the necessity of choosing the appropriate treatment for K. pneumoniae.

scholarly journals Antibiotic Resistance Pattern and Frequency of PER-1, SHV-1 and AMPC Type B-Lactamase Genes in Pseudomonas aeruginosa Isolated from Clinical Samples

2019 ◽  
Vol 13 (1) ◽  
pp. 308-312 ◽  
Author(s):  
Fatemeh F. Amoudizaj ◽  
Elnaz Aghayi ◽  
Milad G. Matin ◽  
Nayemeh Soltani ◽  
Pejman Mala
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antimicrobial Agents ◽  
Treatment Protocol ◽  
Polymyxin B ◽  
Diffusion Method ◽  
Clinical Samples ◽  
Resistance Pattern ◽  
Pcr Method

Background: The existence of Extended Spectrum B-lactamase (ESBL) genes plays an important role in spreading B-lactam antibiotic resistance in the producing strains of these enzymes. The resistance of gram-negative bacteria, such as Pseudomonas aeruginosa, to different antimicrobial agents, especially B-lactams, has increasingly been reported. Objective: This study was conducted to determine the prevalence of TEM-1and VEB-1 beta-lactamases gene in P. aeruginosa isolates through Polymerase Chain Reaction (PCR) method. Methods: 100 clinical isolates of P. aeruginosa were collected from different clinical samples. The antibiotic susceptibility was examined by the disc diffusion method. The presence of PER-1, SHV-1 and AMPC genes was detected by PCR method. Results: Out of the studied P. aeruginosa isolates, 7, 9 and 37 isolates were positive for PER-1, SHV-1 and AMPC B-lactamases resistance genes, respectively. Patients with urinary infection had the most resistant isolates. All isolates (100%) were sensitive to polymyxin B. Conclusion: Antibiotic resistance in isolates of Pseudomonas can be caused by B-lactamases resistance genes. Noticing the increasing rate of the ESBLs producing strains, using the appropriate treatment protocol based on the antibiogram pattern of the strains is highly recommended.

Sign in / Sign up

Export Citation Format

Share Document