Ampicillin tolerance of <i>Legionella pneumophila</i> for counter‐selection of transconjugants in heterospecific matings with <i>Escherichia coli</i> donors

Jain, Bunty; Bender, Larisa; Lück, Paul Christian; Ott, Manfred

doi:10.1002/jobm.3620320616

Cited by 4 publications

(2 citation statements)

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“…Thus, tolerant bacteria are sensitive to the bacteriostatic effect of the antibiotic but have a dramatically decreased susceptibility to drug‐induced killing. Penicillin tolerance has been described in a number of organisms including H. influenzae [9], Legionella pneumophila [27], S. pneumoniae [28], and S. aureus [29]. Penicillin‐tolerant strains of S. pneumoniae have been shown to lose the resistant phenotype after storage at −20°C and, similar to H. pylori , the resistant phenotype could be rescued by consecutive transfers onto penicillin gradient agar plates [30].…”

Section: Discussionmentioning

confidence: 99%

Different Penicillin‐Binding Protein Profiles in Amoxicillin‐Resistant Helicobacter pylori

1999

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Section: Discussionmentioning

confidence: 99%

Different Penicillin‐Binding Protein Profiles in Amoxicillin‐Resistant Helicobacter pylori

1999

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“…While this gene has remained functionally uncharacterized, Legionella sp. have been reported to show resistance to a range of different antibiotics, including nalidixic acid (21), streptomycin (21), and clindamycin (45), with sensitivities reported for rifamycins, macrolides, fluoroquinolones (19,43,48), and ampicillin (32).…”

Section: Resultsmentioning

confidence: 99%

Characterization and Quantitation of a Novel β-Lactamase Gene Found in a Wastewater Treatment Facility and the Surrounding Coastal Ecosystem

Uyaguari

Fichot

Scott

et al. 2011

Appl Environ Microbiol

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Wastewater treatment plants (WWTPs) are engineered structures that collect, concentrate, and treat human waste, ultimately releasing treated wastewater into local environments. While WWTPs efficiently remove most biosolids, it has been shown that many antibiotics and antibiotic-resistant bacteria can survive the treatment process. To determine how WWTPs influence the concentration and dissemination of antibiotic-resistant genes into the environment, a functional metagenomic approach was used to identify a novel antibiotic resistance gene within a WWTP, and quantitative PCR (qPCR) was used to determine gene copy numbers within the facility and the local coastal ecosystem. From the WWTP metagenomic library, the fosmid insert contained in one highly resistant clone (MIC, ϳ416 g ml ؊1 ampicillin) was sequenced and annotated, revealing 33 putative genes, including a 927-bp gene that is 42% identical to a functionally characterized ␤-lactamase from Staphylococcus aureus PC1. Isolation and subcloning of this gene, referred to as bla M-1 , conferred ampicillin resistance to its Escherichia coli host. When normalized to volume, qPCR showed increased concentrations of bla M-1 during initial treatment stages but 2-fold-decreased concentrations during the final treatment stage. The concentration ng ؊1 DNA increased throughout the WWTP process from influent to effluent, suggesting that bla M-1 makes up a significant proportion of the overall genetic material being released into the coastal ecosystem. Average discharge was estimated to be 3.9 ؋ 10 14 copies of the bla M-1 gene released daily into this coastal ecosystem. Furthermore, the gene was observed in all sampled coastal water and sediment samples surrounding the facility. Our results suggest that WWTPs may be a pathway for the dissemination of novel antibiotic resistance genes into the environment.

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Amoxycillin tolerance in Helicobacter pylori

Dore¹,

Osato²,

Realdi³

et al. 1999

Journal of Antimicrobial Chemotherapy

104

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Resistance to amoxycillin in Helicobacter pylori has only recently been reported. To demonstrate the existence of resistance, and to test for the presence of tolerance, 17 amoxycillin-resistant strains of H. pylori, first isolated in Sardinia (Italy) and the USA, were studied. Four amoxycillin-sensitive strains were used as controls. Primary isolates of all test strains exhibited amoxycillin resistance; beta-lactamase activity was not detected. Amoxycillin resistance was lost after storage of strains at -80 degrees C but could be rescued by plating these strains on to amoxycillin gradient plates. MICs and MBCs from rescued isolates ranged from 0.5 to 32 mg/L and from 32 to > 1024 mg/L, respectively. MBC/MIC ratios > or = 32 are characteristic of antibiotic tolerance. The ratios of MBC/MIC of amoxycillin ranged from 32 to > 1024 for the test strains, indicating that these strains were tolerant to the antibiotic. Amoxycillin resistance does occur in H. pylori. Amoxycillin susceptibility testing of H. pylori isolates in patients who fail therapy should include determination of the MBC to detect tolerance.

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Ampicillin tolerance of Legionella pneumophila for counter‐selection of transconjugants in heterospecific matings with Escherichia coli donors

Cited by 4 publications

References 10 publications

Different Penicillin‐Binding Protein Profiles in Amoxicillin‐Resistant Helicobacter pylori

Different Penicillin‐Binding Protein Profiles in Amoxicillin‐Resistant Helicobacter pylori

Characterization and Quantitation of a Novel β-Lactamase Gene Found in a Wastewater Treatment Facility and the Surrounding Coastal Ecosystem

Amoxycillin tolerance in Helicobacter pylori

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