scholarly journals First Emergence of Resistance to Macrolides and Tetracycline Identified in Mannheimia haemolytica and Pasteurella multocida Isolates from Beef Feedlots in Australia

2021 ◽  
Vol 9 (6) ◽  
pp. 1322
Author(s):  
Tamara Alhamami ◽  
Piklu Roy Chowdhury ◽  
Nancy Gomes ◽  
Mandi Carr ◽  
Tania Veltman ◽  
...  
Keyword(s):  
Pasteurella Multocida ◽  
Antimicrobial Agents ◽  
Random Amplified Polymorphic Dna ◽  
Tetracycline Resistance ◽  
Multidrug Resistant ◽  
Mannheimia Haemolytica ◽  
Resistant Isolate ◽  
High Morbidity ◽  
Resistant Phenotype ◽  
South Wales

Bovine respiratory disease (BRD) causes high morbidity and mortality in beef cattle worldwide. Antimicrobial resistance (AMR) monitoring of BRD pathogens is critical to promote appropriate antimicrobial stewardship in veterinary medicine for optimal treatment and control. Here, the susceptibility of Mannheimia haemolytica and Pasteurella multicoda isolates obtained from BRD clinical cases (deep lung swabs at post-mortem) among feedlots in four Australian states (2014–2019) was determined for 19 antimicrobial agents. The M. haemolytica isolates were pan-susceptible to all tested agents apart from a single macrolide-resistant isolate (1/88; 1.1%) from New South Wales (NSW). Much higher frequencies of P. multocida isolates were resistant to tetracycline (18/140; 12.9%), tilmicosin (19/140; 13.6%), tulathromycin/gamithromycin (17/140; 12.1%), and ampicillin/penicillin (6/140; 4.6%). Five P. multocida isolates (3.6%), all obtained from NSW in 2019, exhibited dual resistance to macrolides and tetracycline, and a further two Queensland isolates from 2019 (1.4%) exhibited a multidrug-resistant phenotype to ampicillin/penicillin, tetracycline, and tilmicosin. Random-amplified polymorphic DNA (RAPD) typing identified a high degree of genetic homogeneity among the M. haemolytica isolates, whereas P. multocida isolates were more heterogeneous. Illumina whole genome sequencing identified the genes msr(E) and mph(E)encoding macrolide resistance, tet(R)-tet(H) or tet(Y) encoding tetracycline resistance, and blaROB-1 encoding ampicillin/penicillin resistance in all isolates exhibiting a corresponding resistant phenotype. The exception was the tilmicosin-resistant, tulathromycin/gamithromycin-susceptible phenotype identified in two Queensland isolates, the genetic basis of which could not be determined. These results confirm the first emergence of AMR in M. haemolytica and P. multocida from BRD cases in Australia, which should be closely monitored.

scholarly journals Emergence of Multidrug-Resistant Salmonella enterica Serovar Typhi in Korea

2004 ◽  
Vol 48 (11) ◽  
pp. 4130-4135 ◽  
Author(s):  
Kyungwon Lee ◽  
Dongeun Yong ◽  
Jong Hwa Yum ◽  
Young Sik Lim ◽  
Hyun Sook Kim ◽  
...  
Keyword(s):  
Salmonella Enterica ◽  
Antimicrobial Agents ◽  
Susceptibility Testing ◽  
Multidrug Resistant ◽  
Resistant Isolate ◽  
Asian Countries ◽  
Gene Cassettes ◽  
Salmonella Enterica Serovar Typhi ◽  
Class 1 ◽  
Selection Of

ABSTRACT A chloramphenicol-resistant strain of Salmonella enterica serovar Typhi was first noted in Korea in 1992, when a resistant isolate was detected in a returned traveler. Continued isolation of multidrug-resistant (MDR) strains thereafter in other settings prompted a retrospective analysis of laboratory records and phenotypic and genotypic analyses of 12 chloramphenicol-resistant isolates. Among these, one isolate was resistant only to chloramphenicol, and the other isolates were also resistant to ampicillin and co-trimoxazole. MDR was transferred by conjugation from 9 of the 11 isolates. PCR showed that all isolates had an incompatible group HI1 plasmid, and oriT was detected in 10 isolates, which included strains with an unsuccessful transfer of resistance. All of the ampicillin-resistant isolates had a β-lactamase band of pI 5.4 and bla TEM alleles. A PCR amplicon from an isolate showed that the sequences were identical to those of bla TEM-1, suggesting that all isolates had a TEM-1 β-lactamase. All isolates had class 1 integrons: 10 isolates had integrons of ca. 1.2 kb with dhfr7 gene cassettes, and 1 isolate had an integron of ca. 2.3 kb with aacA4 and bla OXA-1-like gene cassettes. The pulsed-field gel electrophoresis patterns of 7 of 11 MDR isolates were identical and indistinguishable from those reported for isolates in India and Indonesia. In conclusion, some of the MDR strains in Korea are related to those in other Asian countries. Susceptibility testing became necessary for selection of antimicrobial agents for the optimal treatment of patients with the emergence of MDR Salmonella serovar Typhi in Korea.

Streptococcus pneumoniae: An Update on Resistance Patterns in the United States

2008 ◽  
Vol 21 (5) ◽  
pp. 363-370 ◽  
Author(s):  
Jessica A. Starr ◽  
Georgia W. Fox ◽  
Jennifer K. Clayton
Keyword(s):  
United States ◽  
Streptococcus Pneumoniae ◽  
Antimicrobial Agents ◽  
Respiratory Infections ◽  
Tetracycline Resistance ◽  
The United States ◽  
Multidrug Resistant ◽  
Beta Lactam ◽  
Resistance Patterns ◽  
Surveillance Programs

Streptococcus pneumoniae represents an important pathogen in numerous community-acquired respiratory infections. Penicillin resistance to Streptococcus pneumoniae in the United States has approached 35%. Additionally, there has been a significant increase in Streptococcus pneumoniae resistance among many other antimicrobial agents such as cephalosporins, macrolides, trimethoprim–sulfamethoxazole, clindamycin, tetracyclines, and chloramphenicol. Several nationwide surveillance programs have been implemented to quantify the prevalence of Streptococcus pneumoniae resistance in the United States. Overall, beta-lactam, macrolide, trimethoprim–sulfamethoxazole, and tetracycline resistance has increased over the past decade while later generation fluoroquinolones (levofloxacin and moxifloxacin) resistance has remained low. Controlling the spread of resistant pneumococcal isolates and preventing the development of both fluoroquinolone and multidrug resistant isolates will require a multidisciplinary approach involving physicians, pharmacists, microbiologists, and epidemiologists.

scholarly journals Antimicrobial Susceptibility and Characterization of Resistance Mechanisms of Corynebacterium urealyticum Clinical Isolates

Antibiotics ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 404
Author(s):  
Itziar Chapartegui-González ◽  
Marta Fernández-Martínez ◽  
Ana Rodríguez-Fernández ◽  
Danilo J. P. Rocha ◽  
Eric R. G. R. Aguiar ◽  
...  
Keyword(s):  
Antimicrobial Susceptibility ◽  
Antimicrobial Agents ◽  
Point Mutations ◽  
Tetracycline Resistance ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Resistance Rate ◽  
Clinical Isolates ◽  
Tract Infections ◽  
Corynebacterium Urealyticum

Corynebacterium urealyticum is a non-diphtherial urease-producing clinically relevant corynebacterial, most frequently involved in urinary tract infections. Most of the C. urealyticum clinical isolates are frequently resistant to several antibiotics. We investigated the susceptibility of 40 C. urealyticum isolated in our institution during the period 2005–2017 to eight compounds representative of the main clinically relevant classes of antimicrobial agents. Antimicrobial susceptibility was determined by the Epsilometer test. Resistance genes were searched by PCR. All strains were susceptible to vancomycin whereas linezolid and rifampicin also showed good activity (MICs90 = 1 and 0.4 mg/L, respectively). Almost all isolates (39/40, 97.5%) were multidrug resistant. The highest resistance rate was observed for ampicillin (100%), followed by erythromycin (95%) and levofloxacin (95%). Ampicillin resistance was associated with the presence of the blaA gene, encoding a class A β-lactamase. The two rifampicin-resistant strains showed point mutations driving amino acid replacements in conserved residues of RNA polymerase subunit β (RpoB). Tetracycline resistance was due to an efflux-mediated mechanism. Thirty-nine PFGE patterns were identified among the 40 C. urealyticum, indicating that they were not clonally related, but producing sporadic infections. These findings raise the need of maintaining surveillance strategies among this multidrug resistant pathogen.

scholarly journals Antimicrobial Resistance Genes in Porcine Pasteurella multocida Are Not Associated with Its Antimicrobial Susceptibility Pattern

Antibiotics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 614
Author(s):  
Máximo Petrocchi-Rilo ◽  
César-B. Gutiérrez-Martín ◽  
Esther Pérez-Fernández ◽  
Anna Vilaró ◽  
Lorenzo Fraile ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Antimicrobial Susceptibility ◽  
Pasteurella Multocida ◽  
Antimicrobial Agents ◽  
Tetracycline Resistance ◽  
Susceptibility Pattern ◽  
Antimicrobial Susceptibility Pattern ◽  
Tetracycline Resistance Genes ◽  
Antimicrobial Resistance Genes ◽  
Western Spain

Forty-eight Pasteurella multocida isolates were recovered from porcine pneumonic lungs collected from farms in “Castilla y León” (north-western Spain) in 2017–2019. These isolates were characterized for their minimal inhibition concentrations to twelve antimicrobial agents and for the appearance of eight resistance genes: tetA, tetB, blaROB1, blaTEM, ermA, ermC, mphE and msrE. Relevant resistance percentages were shown against tetracyclines (52.1% for doxycycline, 68.7% for oxytetracycline), sulphamethoxazole/trimethoprim (43.7%) and tiamulin (25.0%), thus suggesting that P. multocida isolates were mostly susceptible to amoxicillin, ceftiofur, enrofloxacin, florfenicol, marbofloxacin and macrolides. Overall, 29.2% of isolates were resistant to more than two antimicrobials. The tetracycline resistance genes (tetA and tetB) were detected in 22.9% of the isolates, but none were positive to both simultaneously; blaROB1 and blaTEM genes were found in one third of isolates but both genes were detected simultaneously in only one isolate. The ermC gene was observed in 41.7% of isolates, a percentage that decreased to 22.9% for msrE; finally, ermA was harbored by 16.7% and mphE was not found in any of them. Six clusters were established based on hierarchical clustering analysis on antimicrobial susceptibility for the twelve antimicrobials. Generally, it was unable to foresee the antimicrobial susceptibility pattern for each family and the association of each particular isolate inside the clusters established from the presence or absence of the resistance genes analyzed.

scholarly journals Bacterial Nosocomial Infections: Multidrug Resistance as a Trigger for the Development of Novel Antimicrobials

Antibiotics ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 942
Author(s):  
Sílvia A. Sousa ◽  
Joana R. Feliciano ◽  
Tiago Pita ◽  
Catarina F. Soeiro ◽  
Beatriz L. Mendes ◽  
...  
Keyword(s):  
Multidrug Resistance ◽  
Nosocomial Infections ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Healthcare Systems ◽  
High Morbidity ◽  
Therapeutic Approaches ◽  
New Compounds ◽  
Novel Therapeutic

Nosocomial bacterial infections are associated with high morbidity and mortality, posing a huge burden to healthcare systems worldwide. The ongoing COVID-19 pandemic, with the raised hospitalization of patients and the increased use of antimicrobial agents, boosted the emergence of difficult-to-treat multidrug-resistant (MDR) bacteria in hospital settings. Therefore, current available antibiotic treatments often have limited or no efficacy against nosocomial bacterial infections, and novel therapeutic approaches need to be considered. In this review, we analyze current antibacterial alternatives under investigation, focusing on metal-based complexes, antimicrobial peptides, and antisense antimicrobial therapeutics. The association of new compounds with older, commercially available antibiotics and the repurposing of existing drugs are also revised in this work.

scholarly journals A Review of the Innate Immune Evasion Mechanisms and Status of Vaccine Development of Klebsiella pneumonia

2021 ◽  
pp. 33-47
Author(s):  
Fredrick Ruo Tiria ◽  
Lillian Musila
Keyword(s):  
Immune Evasion ◽  
Antimicrobial Agents ◽  
Vaccine Development ◽  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Immune Defense ◽  
Klebsiella Pneumonia ◽  
High Morbidity ◽  
Pharmaceutical Industries ◽  
Tract Infections

Klebsiella pneumoniae (KP) is a human pathogen causing a broad spectrum of diseases such as urinary tract infections (UTI), pneumonia, pyogenic liver abscess, bloodstream infections, and sepsis. Neonate, geriatric and immunocompromised individuals are the most vulnerable to KP infections. The success of KP as an infectious agent is due to the evolution of various mechanisms to evade the host's immune system. These diverse mechanisms have led to the dominance of KP infections in community settings where hypervirulent strains predominate and in hospital-acquired infections where multidrug-resistant strains predominate. KP infections in the past decades have been increasingly associated with high morbidity and mortality due to the emergence of multidrug-resistant and hypervirulent strains capable of evading both the internal immune defense mechanisms and external antimicrobial agents. The pharmaceutical industries have very few and often expensive new antibiotics in the pipeline, offering little hope for antibiotic therapy. The development of new therapeutic strategies such as polyvalent, biconjugate vaccines that can provide protective immunity, especially against vulnerable populations, can mitigate the effects of KP infections. In this review, we discuss the virulence mechanisms of KP and how it evades the innate host immunity, and the interplay between the virulence and immune evasion strategies. The progress in the search for a vaccine to protect against KP infections will also be highlighted.

scholarly journals A Chimeric Cationic Peptide Composed of Human β-Defensin 3 and Human β-Defensin 4 Exhibits Improved Antibacterial Activity and Salt Resistance

2021 ◽  
Vol 12 ◽  
Author(s):  
Wenjing Yu ◽  
Nianzhi Ning ◽  
Ying Xue ◽  
Yanyu Huang ◽  
Feng Guo ◽  
...  
Keyword(s):  
Antibacterial Activity ◽  
Antimicrobial Agents ◽  
A549 Cells ◽  
Multidrug Resistant ◽  
Salt Resistance ◽  
High Salt ◽  
Resistant Isolate ◽  
Klebsiella Pneumonia ◽  
Staphyloccocus Aureus

Human beta-defensins (hBDs) play an important role in the host defense against various microbes, showing different levels of antibacterial activity and salt resistance in vitro. It is of interest to investigate whether can chimeric hBD analogs enhanced antibacterial activity and salt resistance. In this study, we designed a chimeric human defensin, named H4, by combining sequences of human beta-defensin-3 (hBD-3) and human beta-defensin-4 (hBD-4), then evaluated its antibacterial activity, salt resistance, and cytotoxic effects. The result showed that the antibacterial activity of H4 against most tested strains, including Klebsiella pneumonia, Enterococcus faecalis, Staphyloccocus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumonia, and Acinetobacter baumannii was significantly improved compared to that of hBD-3 and hBD-4. Notably, H4 exhibited significantly better antibacterial activity against multidrug resistant isolate A. baumannii MDR-ZJ06 than commonly used antibiotics. Chimeric H4 still showed more than 80% antibacterial activity at high salt concentration (150 μM), which proves its good salt tolerance. The cytotoxic effect assay showed that the toxicity of H4 to Hela, Vero, A549 cells and erythrocytes at a low dose (<10 μg/ml) was similar to that of hBD-3 and hBD-4. In conclusion, given its broad spectrum of antibacterial activity and high salt resistance, chimeric H4 could serve as a promising template for new therapeutic antimicrobial agents.

scholarly journals Acinetobacter species meningitis in children: a case series from Karachi, Pakistan

2011 ◽  
Vol 5 (11) ◽  
pp. 809-814 ◽  
Author(s):  
Ali Faisal Saleem ◽  
Muhammad Shafaat Shah ◽  
Abdul Sattar Shaikh ◽  
Fatima Mir ◽  
Anita K M Zaidi
Keyword(s):  
Antimicrobial Agents ◽  
Medical Center ◽  
External Ventricular Drain ◽  
Tertiary Care ◽  
Case Series ◽  
Polymyxin B ◽  
Multidrug Resistant ◽  
Resistant Isolate ◽  
Acinetobacter Species ◽  
Tertiary Care Medical Center

Introduction: Multidrug-resistant strains of Acinetobacter pose a serious therapeutic dilemma in hospital practice, particularly when they cause meningitis, as the few antimicrobial agents to which these isolates are susceptible have poor central nervous system (CNS) penetration.  Methodology: We retrospectively reviewed the clinical course and outcome of eight consecutive cases of meningitis due to Acinetobacter spp. in children ages 15 years or less, seen in a tertiary care medical center in Karachi, Pakistan. Results: Of the eight cases of Acinetobacter meningitis, isolates from five patients were pan-resistant, and two were multidrug-resistant. A neurosurgical procedure was performed in five of eight patients followed by external ventricular drain insertion prior to the development of infection. Seven received intravenous (IV) polymyxin (mean; 12.8 days), while 5/8 also received intrathecal (IT) polymyxin (mean; 12.0 days). The mean length of hospitalization was 38.7 ± 19 days. All patients achieved cerebrospinal fluid (CSF) culture negativity by the end of treatment (mean; 5.4 days). Two patients died: one with pan-resistant Acinetobacter, and the second with a multi-drug resistant isolate. Conclusion: Post-neurosurgical multidrug-resistant and pan-resistant Acinetobacter meningitis can be successfully treated if appropriate antimicrobial therapy is instituted early. The role of IT polymyxin B administration alone versus combination therapy (IV and IT) needs further study.  

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