1
|
Haudiquet M, Le Bris J, Nucci A, Bonnin RA, Domingo-Calap P, Rocha EPC, Rendueles O. Capsules and their traits shape phage susceptibility and plasmid conjugation efficiency. Nat Commun 2024; 15:2032. [PMID: 38448399 PMCID: PMC10918111 DOI: 10.1038/s41467-024-46147-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 02/14/2024] [Indexed: 03/08/2024] Open
Abstract
Bacterial evolution is affected by mobile genetic elements like phages and conjugative plasmids, offering new adaptive traits while incurring fitness costs. Their infection is affected by the bacterial capsule. Yet, its importance has been difficult to quantify because of the high diversity of confounding mechanisms in bacterial genomes such as anti-viral systems and surface receptor modifications. Swapping capsule loci between Klebsiella pneumoniae strains allowed us to quantify their impact on plasmid and phage infection independently of genetic background. Capsule swaps systematically invert phage susceptibility, revealing serotypes as key determinants of phage infection. Capsule types also influence conjugation efficiency in both donor and recipient cells, a mechanism shaped by capsule volume and conjugative pilus structure. Comparative genomics confirmed that more permissive serotypes in the lab correspond to the strains acquiring more conjugative plasmids in nature. The least capsule-sensitive pili (F-like) are the most frequent in the species' plasmids, and are the only ones associated with both antibiotic resistance and virulence factors, driving the convergence between virulence and antibiotics resistance in the population. These results show how traits of cellular envelopes define slow and fast lanes of infection by mobile genetic elements, with implications for population dynamics and horizontal gene transfer.
Collapse
Affiliation(s)
- Matthieu Haudiquet
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France.
- Ecole Doctoral FIRE-Programme Bettencourt, CRI, Paris, France.
| | - Julie Le Bris
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France
- Sorbonne Université, Collège Doctoral, Ecole Doctorale Complexité du Vivant, 75005, Paris, France
| | - Amandine Nucci
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France
| | - Rémy A Bonnin
- Team Resist UMR1184 Université Paris Saclay, CEA, Inserm, Le Kremlin-Bicêtre, Paris, France
- Service de bactériologie, Hôpital Bicêtre, Université Paris Saclay, AP-HP, Le Kremlin-Bicêtre, Paris, France
- Centre National de Référence Associé de la Résistance aux Antibiotiques, Le Kremlin-Bicêtre, Paris, France
| | - Pilar Domingo-Calap
- Instituto de Biología Integrativa de Sistemas, Universitat de València-CSIC, 46980, Paterna, Spain
| | - Eduardo P C Rocha
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France.
| | - Olaya Rendueles
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France.
| |
Collapse
|
2
|
McKeithen-Mead SA, Grossman AD. Timing of integration into the chromosome is critical for the fitness of an integrative and conjugative element and its bacterial host. PLoS Genet 2023; 19:e1010524. [PMID: 36780569 PMCID: PMC9956884 DOI: 10.1371/journal.pgen.1010524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 02/24/2023] [Accepted: 01/31/2023] [Indexed: 02/15/2023] Open
Abstract
Integrative and conjugative elements (ICEs) are major contributors to genome plasticity in bacteria. ICEs reside integrated in the chromosome of a host bacterium and are passively propagated during chromosome replication and cell division. When activated, ICEs excise from the chromosome and may be transferred through the ICE-encoded conjugation machinery into a recipient cell. Integration into the chromosome of the new host generates a stable transconjugant. Although integration into the chromosome of a new host is critical for the stable acquisition of ICEs, few studies have directly investigated the molecular events that occur in recipient cells during generation of a stable transconjugant. We found that integration of ICEBs1, an ICE of Bacillus subtilis, occurred several generations after initial transfer to a new host. Premature integration in new hosts led to cell death and hence decreased fitness of the ICE and transconjugants. Host lethality due to premature integration was caused by rolling circle replication that initiated in the integrated ICEBs1 and extended into the host chromosome, resulting in catastrophic genome instability. Our results demonstrate that the timing of integration of an ICE is linked to cessation of autonomous replication of the ICE, and that perturbing this linkage leads to a decrease in ICE and host fitness due to a loss of viability of transconjugants. Linking integration to cessation of autonomous replication appears to be a conserved regulatory scheme for mobile genetic elements that both replicate and integrate into the chromosome of their host.
Collapse
Affiliation(s)
- Saria A. McKeithen-Mead
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Alan D. Grossman
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| |
Collapse
|
3
|
Haudiquet M, Buffet A, Rendueles O, Rocha EPC. Interplay between the cell envelope and mobile genetic elements shapes gene flow in populations of the nosocomial pathogen Klebsiella pneumoniae. PLoS Biol 2021; 19:e3001276. [PMID: 34228700 PMCID: PMC8259999 DOI: 10.1371/journal.pbio.3001276] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 05/07/2021] [Indexed: 01/01/2023] Open
Abstract
Mobile genetic elements (MGEs) drive genetic transfers between bacteria using mechanisms that require a physical interaction with the cellular envelope. In the high-priority multidrug-resistant nosocomial pathogens (ESKAPE), the first point of contact between the cell and virions or conjugative pili is the capsule. While the capsule can be a barrier to MGEs, it also evolves rapidly by horizontal gene transfer (HGT). Here, we aim at understanding this apparent contradiction by studying the covariation between the repertoire of capsule genes and MGEs in approximately 4,000 genomes of Klebsiella pneumoniae (Kpn). We show that capsules drive phage-mediated gene flow between closely related serotypes. Such serotype-specific phage predation also explains the frequent inactivation of capsule genes, observed in more than 3% of the genomes. Inactivation is strongly epistatic, recapitulating the capsule biosynthetic pathway. We show that conjugative plasmids are acquired at higher rates in natural isolates lacking a functional capsular locus and confirmed experimentally this result in capsule mutants. This suggests that capsule inactivation by phage pressure facilitates its subsequent reacquisition by conjugation. Accordingly, capsule reacquisition leaves long recombination tracts around the capsular locus. The loss and regain process rewires gene flow toward other lineages whenever it leads to serotype swaps. Such changes happen preferentially between chemically related serotypes, hinting that the fitness of serotype-swapped strains depends on the host genetic background. These results enlighten the bases of trade-offs between the evolution of virulence and multidrug resistance and caution that some alternatives to antibiotics by selecting for capsule inactivation may facilitate the acquisition of antibiotic resistance genes (ARGs). A study of how the complex interaction between capsules and mobile genetic elements shapes gene flow in populations of Klebsiella pneumoniae reveals that capsule inactivation by phage pressure facilitates its subsequent re-acquisition by conjugation, and this loss and re-gain process influences the gene flow towards other lineages whenever it leads to serotype changes.
Collapse
Affiliation(s)
- Matthieu Haudiquet
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
- Ecole Doctoral FIRE–Programme Bettencourt, CRI, Paris, France
- * E-mail:
| | - Amandine Buffet
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| | - Olaya Rendueles
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| | - Eduardo P. C. Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| |
Collapse
|
4
|
Rendueles O, de Sousa JAM, Bernheim A, Touchon M, Rocha EPC. Genetic exchanges are more frequent in bacteria encoding capsules. PLoS Genet 2018; 14:e1007862. [PMID: 30576310 PMCID: PMC6322790 DOI: 10.1371/journal.pgen.1007862] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/07/2019] [Accepted: 11/29/2018] [Indexed: 12/12/2022] Open
Abstract
Capsules allow bacteria to colonize novel environments, to withstand numerous stresses, and to resist antibiotics. Yet, even though genetic exchanges with other cells should be adaptive under such circumstances, it has been suggested that capsules lower the rates of homologous recombination and horizontal gene transfer. We analysed over one hundred pan-genomes and thousands of bacterial genomes for the evidence of an association between genetic exchanges (or lack thereof) and the presence of a capsule system. We found that bacteria encoding capsules have larger pan-genomes, higher rates of horizontal gene transfer, and higher rates of homologous recombination in their core genomes. Accordingly, genomes encoding capsules have more plasmids, conjugative elements, transposases, prophages, and integrons. Furthermore, capsular loci are frequent in plasmids, and can be found in prophages. These results are valid for Bacteria, independently of their ability to be naturally transformable. Since we have shown previously that capsules are commonly present in nosocomial pathogens, we analysed their co-occurrence with antibiotic resistance genes. Genomes encoding capsules have more antibiotic resistance genes, especially those encoding efflux pumps, and they constitute the majority of the most worrisome nosocomial bacteria. We conclude that bacteria with capsule systems are more genetically diverse and have fast-evolving gene repertoires, which may further contribute to their success in colonizing novel niches such as humans under antibiotic therapy. Previous works showed that bacteria encoding capsules are better colonizers and are dominant in most environments suggesting a positive role for capsules in the genetic diversification of bacteria. Yet, it has been repeatedly suggested, based almost exclusively studies in few model species, that such bacteria are less diverse and engage in fewer genetic exchanges. Here, we reverse the current paradigm and show that bacteria encoding capsules have larger and more diverse gene repertoires, which change faster by horizontal gene transfer and recombination. Our study alters the traditional view of the capsule as a barrier to gene flow and raises novel questions about the role of capsules in bacterial adaptation.
Collapse
Affiliation(s)
- Olaya Rendueles
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
- * E-mail:
| | - Jorge A. Moura de Sousa
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Aude Bernheim
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Marie Touchon
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Eduardo P. C. Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| |
Collapse
|
5
|
Fleury C, Resman F, Rau J, Riesbeck K. Prevalence, distribution and transfer of small β-lactamase-containing plasmids in Swedish Haemophilus influenzae. J Antimicrob Chemother 2013; 69:1238-42. [PMID: 24381073 DOI: 10.1093/jac/dkt511] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES The β-lactamase genes of Haemophilus influenzae are commonly positioned on large integrative and conjugative elements, but a group of blaTEM-carrying small plasmids (4000-6000 bp) with a common structural backbone have recently been characterized. In this study we investigated the epidemiological significance and potential for transfer of this group of small plasmids. METHODS We developed a two-step PCR assay to screen for and type this group of resistance plasmids in H. influenzae. A large collection of respiratory isolates (n = 2845) from south Sweden, obtained from 2009 to 2011, as well as a collection of invasive Swedish H. influenzae from 1997 to 2010 (n = 310) was screened. The distribution of plasmid types among clinical isolates was investigated using multilocus sequence typing (MLST). RESULTS In the collection, 15.8% of β-lactamase-producing isolates and 1.4% of total isolates possessed a small plasmid with the signature structure. The plasmids were genetically conserved and widely spread geographically. MLST revealed that the spread of small plasmids occurred by both clonal expansion and horizontal transfer. In vitro experiments suggested that one plasmid type, pN223, can transfer ampicillin resistance to susceptible Escherichia coli. CONCLUSIONS Small β-lactamase-encoding plasmids constitute a significant mechanism for β-lactam resistance in H. influenzae and can spread through clonal expansion of resistant clones as well as through horizontal plasmid transfer.
Collapse
Affiliation(s)
- Christophe Fleury
- Medical Microbiology, Department of Laboratory Medicine, Lund University, Malmö, Sweden
| | | | | | | |
Collapse
|
6
|
Kawasaki H, Takao M, Koiso A, Tonomura K. Genetic Rearrangement of Plasmids: In Vivo Recombination between a Dehalogenation Plasmid and Multiple-Resistance Plasmid RP4 in Pseudomonas sp. Appl Environ Microbiol 2010; 49:1544-6. [PMID: 16346824 PMCID: PMC241765 DOI: 10.1128/aem.49.6.1544-1546.1985] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
When Moraxella plasmid pUO1 encoding haloacetate dehalogenase and mercury resistance coexisted with IncP-1 plasmid RP4 in Pseudomonas sp., genetic exchange between the plasmids often occurred, probably by site-specific recombination. The recombinant plasmids obtained were classified into four groups on the basis of phenotype. Representative plasmids for each group were analyzed for DNA composition and function, and the mechanism for the formation of these plasmids was sought. They were inherited stably in Escherichia coli and a Pseudomonas sp.
Collapse
Affiliation(s)
- H Kawasaki
- Department of Agricultural Chemistry, College of Agriculture, University of Osaka Prefecture, Sakai, Osaka 591, Japan
| | | | | | | |
Collapse
|
7
|
Juhas M, Power PM, Harding RM, Ferguson DJP, Dimopoulou ID, Elamin ARE, Mohd-Zain Z, Hood DW, Adegbola R, Erwin A, Smith A, Munson RS, Harrison A, Mansfield L, Bentley S, Crook DW. Sequence and functional analyses of Haemophilus spp. genomic islands. Genome Biol 2008; 8:R237. [PMID: 17996041 PMCID: PMC2258188 DOI: 10.1186/gb-2007-8-11-r237] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 09/14/2007] [Accepted: 11/08/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND A major part of horizontal gene transfer that contributes to the diversification and adaptation of bacteria is facilitated by genomic islands. The evolution of these islands is poorly understood. Some progress was made with the identification of a set of phylogenetically related genomic islands among the Proteobacteria, recognized from the investigation of the evolutionary origins of a Haemophilus influenzae antibiotic resistance island, namely ICEHin1056. More clarity comes from this comparative analysis of seven complete sequences of the ICEHin1056 genomic island subfamily. RESULTS These genomic islands have core and accessory genes in approximately equal proportion, with none demonstrating recent acquisition from other islands. The number of variable sites within core genes is similar to that found in the host bacteria. Furthermore, the GC content of the core genes is similar to that of the host bacteria (38% to 40%). Most of the core gene content is formed by the syntenic type IV secretion system dependent conjugative module and replicative module. GC content and lack of variable sites indicate that the antibiotic resistance genes were acquired relatively recently. An analysis of conjugation efficiency and antibiotic susceptibility demonstrates that phenotypic expression of genomic island-borne genes differs between different hosts. CONCLUSION Genomic islands of the ICEHin1056 subfamily have a longstanding relationship with H. influenzae and H. parainfluenzae and are co-evolving as semi-autonomous genomes within the 'supragenomes' of their host species. They have promoted bacterial diversity and adaptation through becoming efficient vectors of antibiotic resistance by the recent acquisition of antibiotic resistance transposons.
Collapse
Affiliation(s)
- Mario Juhas
- Clinical Microbiology and Infectious Diseases, NDCLS, University of Oxford, Headley Way, Oxford OX3 9DU, UK.
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Juhas M, Crook DW, Dimopoulou ID, Lunter G, Harding RM, Ferguson DJP, Hood DW. Novel type IV secretion system involved in propagation of genomic islands. J Bacteriol 2007; 189:761-71. [PMID: 17122343 PMCID: PMC1797279 DOI: 10.1128/jb.01327-06] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Accepted: 11/10/2006] [Indexed: 12/30/2022] Open
Abstract
Type IV secretion systems (T4SSs) mediate horizontal gene transfer, thus contributing to genome plasticity, evolution of infectious pathogens, and dissemination of antibiotic resistance and other virulence traits. A gene cluster of the Haemophilus influenzae genomic island ICEHin1056 has been identified as a T4SS involved in the propagation of genomic islands. This T4SS is novel and evolutionarily distant from the previously described systems. Mutation analysis showed that inactivation of key genes of this system resulted in a loss of phenotypic traits provided by a T4SS. Seven of 10 mutants with a mutation in this T4SS did not express the type IV secretion pilus. Correspondingly, disruption of the genes resulted in up to 100,000-fold reductions in conjugation frequencies compared to those of the parent strain. Moreover, the expression of this T4SS was found to be positively regulated by one of its components, the tfc24 gene. We concluded that this gene cluster represents a novel family of T4SSs involved in propagation of genomic islands.
Collapse
Affiliation(s)
- Mario Juhas
- Clinical Microbiology and Infectious Diseases, Nuffield Department of Clinical Laboratory Sciences, University of Oxford, Headington, OX3 9DU Oxford, United Kingdom.
| | | | | | | | | | | | | |
Collapse
|
9
|
Dimopoulou ID, Russell JE, Mohd-Zain Z, Herbert R, Crook DW. Site-specific recombination with the chromosomal tRNA(Leu) gene by the large conjugative Haemophilus resistance plasmid. Antimicrob Agents Chemother 2002; 46:1602-3. [PMID: 11959612 PMCID: PMC127194 DOI: 10.1128/aac.46.5.1602-1603.2002] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Characterization of the sequences involved in recombination of the Haemophilus plasmid p1056 with the Haemophilus influenzae chromosome produced evidence indicating site-specific recombination with chromosomal tRNA(Leu). attP sequences identical to those of p1056 were found in six plasmids of diverse origin, suggesting that a family of Haemophilus plasmids recombines with chromosomal tRNA(Leu).
Collapse
Affiliation(s)
- Ioanna D Dimopoulou
- Interdepartmental Academic Unit of Infectious Diseases and Microbiology, Oxford University, John Radcliffe Hospital, Headington, Oxford OX3 9DU, United Kingdom
| | | | | | | | | |
Collapse
|
10
|
Abstract
Haemophilus influenzae is a fastidious Gram-negative coccobacilli that is a common commensal in the human upper respiratory tract. However, certain strains of this bacterium, including those considered to be nontypeable (NTHi), can cause human diseases ranging from otitis media to meningitis. Although naturally competent, NTHi take up plasmids by transformation very inefficiently, if at all. Many clinical isolates have also proven refractory to the introduction of currently available shuttle vectors via electroporation. Further, it has been difficult to determine protein expression from these vectors, unless specific antisera has been raised or a phenotype conferred. To address these problems, we have designed and constructed a set of broad host range vectors that are transferable via intergeneric conjugation with an Escherichia coli strain carrying chromosomally-encoded transfer functions. These vectors provide a site for cloning promoter::MCS regions and carry genes encoding resistance to one of two different antibiotics. This conjugal system allows the expression of marker genes in NTHi strains, enabling researchers to track the microbe's progress either in vivo using the infant rat model of infection, or in vitro through invasions of human tissue culture cell lines.
Collapse
Affiliation(s)
- D A Daines
- Department of Molecular Microbiology and Immunology. University of Missouri - Columbia, M616 Medical Science Building, DCO44.00, Columbia, MO 65212, USA.
| | | |
Collapse
|
11
|
Sánchez L, Pan W, Viñas M, Nikaido H. The acrAB homolog of Haemophilus influenzae codes for a functional multidrug efflux pump. J Bacteriol 1997; 179:6855-7. [PMID: 9352940 PMCID: PMC179619 DOI: 10.1128/jb.179.21.6855-6857.1997] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Disruption of gene HI0894 or HI0895 in Haemophilus influenzae Rd, homologs of Escherichia coli acrAB multidrug efflux genes, caused hypersusceptibility to erythromycin, rifampin, novobiocin, and dyes such as ethidium bromide and crystal violet and increased accumulation of radioactive erythromycin, showing that these genes are expressed and contribute to the baseline level resistance of this organism through active drug efflux. The gene disruption did not produce detectable changes in susceptibility to several other antibiotics, possibly because rapid influx of small antibiotic molecules through the large H. influenzae porin channels counterbalances their efflux.
Collapse
Affiliation(s)
- L Sánchez
- Department of Molecular and Cell Biology, University of California, Berkeley 94720-3206, USA
| | | | | | | |
Collapse
|
12
|
Walter RB, Morton KA, Stuy JH. The sequence of the Haemophilus influenzae mutB gene indicates it encodes a DNA helicase II-like protein. Gene 1993; 136:35-40. [PMID: 8294031 DOI: 10.1016/0378-1119(93)90444-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A 6.2-kb Haemophilus influenzae genomic DNA fragment which partially complemented both the mutator and ultraviolet light sensitive (UVs) phenotypes of the H. influenzae mutB1 mutant was isolated. This fragment was also able to complement the UVs phenotype of Escherichia coli uvrD mutant hosts. The uvrD+ gene complemented the mutator phenotype of mutB1 hosts. The nucleotide (nt) sequence of the 6.2-kb fragment revealed an open reading frame (ORF) of 2184 bp. This ORF shows similarity at both the nt and amino acid (aa) levels with the uvrD gene of E. coli. Comparison of the sequences revealed eight regions of aa conservation in addition to seven previously identified helicase superfamily domains. The nt sequence 5' to the mutB ORF contains several potential regulatory motifs, including a LexA-binding site. Based upon these observations, we are confident that the mutB gene of H. influenzae encodes an ATP-dependent DNA helicase-like activity.
Collapse
Affiliation(s)
- R B Walter
- Department of Biology, Southwest Texas State University, San Marcos 78666
| | | | | |
Collapse
|
13
|
Vandenbroucke-Grauls CM. The threat of multiresistant microorganisms. Eur J Clin Microbiol Infect Dis 1993; 12 Suppl 1:S27-30. [PMID: 8386639 DOI: 10.1007/bf02389874] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Enthusiasm about newly developed antimicrobial agents and disappointment because of the development of resistance have been alternating in the decades since the introduction of antibacterial chemotherapy around 1940. During the last few years several mechanisms of bacterial resistance have been elucidated, and new insights into the genetic basis of multiresistance have been gained. The clinical implications of multiresistance depend on timely recognition of the problem, i.e. knowledge of the epidemiology of multiresistant microorganisms and the availability of alternative drugs. A particular problem arises from the fact that infections with multiresistant microorganisms often occur in the most critically ill patients.
Collapse
|
14
|
Stuy JH, Walter RB. Cloning, characterization, and DNA base sequence of the high-level streptomycin resistance gene strA1 of Haemophilus influenzae Rd. J Bacteriol 1992; 174:5604-8. [PMID: 1512195 PMCID: PMC206505 DOI: 10.1128/jb.174.17.5604-5608.1992] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The high-level streptomycin resistance strA1 gene of Haemophilus influenzae Rd was cloned in plasmid pAT4 as a 2.1-kbp EcoRI insert. It was later replaced in pAT4 by the wild-type strA+ gene. Plasmid pAT4 carrying the strA+ gene is highly unstable and renders chromosomally resistant recipients sensitive to streptomycin. The strA+ gene and the instability factor both reside on a 500-base HindIII-EcoRI subfragment. The two biological activities are also expressed in Escherichia coli. Both wild-type (strA+) and mutant (strA1) genes were sequenced. They show considerable nucleotide homology with the E. coli strA+ gene and its product.
Collapse
Affiliation(s)
- J H Stuy
- Department of Biological Science, Florida State University, Tallahassee 32306
| | | |
Collapse
|
15
|
de Groot R, Dzoljic-Danilovic G, van Klingeren B, Goessens WH, Neyens HJ. Antibiotic resistance in Haemophilus influenzae: mechanisms, clinical importance and consequences for therapy. Eur J Pediatr 1991; 150:534-46. [PMID: 1954956 DOI: 10.1007/bf02072202] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Invasive and non-invasive infections caused by Haemophilus influenzae are frequently diagnosed in children below the age of 5 years. The treatment of choice for these infections was ampicillin. However, since the early 1970s the increasing prevalence of resistance to ampicillin and other antibiotics has necessitated major changes in antibiotic therapy. This article summarizes some of the important clinical features of diseases caused by H. influenzae. The epidemiology, the problems with in vitro susceptibility testing and the mechanisms of resistance to major antibiotics are reviewed. The consequences of antibiotic resistance for the treatment of diseases caused by H. influenzae are discussed.
Collapse
Affiliation(s)
- R de Groot
- Department of Paediatrics, Sophia Children's Hospital/University Hospital Rotterdam, The Netherlands
| | | | | | | | | |
Collapse
|
16
|
Misawa N, Yamano S, Ikenaga H. Production of beta-carotene in Zymomonas mobilis and Agrobacterium tumefaciens by introduction of the biosynthesis genes from Erwinia uredovora. Appl Environ Microbiol 1991; 57:1847-9. [PMID: 1872613 PMCID: PMC183481 DOI: 10.1128/aem.57.6.1847-1849.1991] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The Erwinia uredovora crtB, crtE, crtI, and crtY genes required for beta-carotene biosynthesis were introduced by conjugal transfer into an ethanol-producing bacterium, Zymomonas mobilis, and a phytopathogenic bacterium, Agrobacterium tumefaciens, in which no carotenoid is synthesized. The transconjugants of Z. mobilis and A. tumefaciens carrying these genes appeared as yellow colonies and produced 220 and 350 micrograms of beta-carotene per g of dry weight, respectively, in the stationary phase in liquid culture.
Collapse
Affiliation(s)
- N Misawa
- Central Laboratories for Key Technology, Kirin Brewery Co., Ltd., Gunma, Japan
| | | | | |
Collapse
|
17
|
Abstract
The Haemophilus influenzae Rd rec-1+ gene was cloned from a partial chromosomal digest into a plasmid vector as a 20-kilobase-pair (kbp) BstEII fragment and then subcloned. The smallest subclone with rec-1+ activity carried a 3.1-kbp EcoRI fragment. The identity of the rec-I gene in these clones was confirmed by transforming an Rd strain carrying a leaky rec-1 mutation (recA4) to resistance to methyl methanesulfonate (MMS) by using whole or digested plasmids. It was demonstrated that the Rec+ phenotype of the MMSr transformants was linked to the strA, novAB, and mmsA loci, as expected if the recA4 allele had been replaced by rec-1+. In growing cultures (rec-1 or rec+), all rec-1+-carrying plasmids induced near-maximal levels of transformability when their hosts reached stationary phase; these levels are 100 to 1,000 times higher than the values seen with strains not carrying a Rec plasmid. Transfer of the 3.1-kbp subclone was greatly reduced compared with transfer of similarly sized vector plasmids, and the resulting transformants grew slowly; this suggests an explanation of my failure to directly clone this fragment from chromosomal DNA digests. Transfer of a rec-1+ plasmid to a very poorly genetically transformable H. influenzae Rb strain resulted in greatly increased transformability. Transfer of such plasmids to a noncompetent H. influenzae Rc strain did not render this strain competent. It is suggested that transformability of Rd and Rb strains is limited by rec-1 expression but that the noncompetence of Rc has some other basis.
Collapse
Affiliation(s)
- J H Stuy
- Department of Biological Science, Florida State University, Tallahassee 32306
| |
Collapse
|
18
|
Jørgensen ST, Lester A, Hansen JW, Jørgensen A. Molecular epidemiology of antibiotic resistant Haemophilus influenzae isolated in Denmark 1981-87. APMIS 1989; 97:619-24. [PMID: 2787663 DOI: 10.1111/j.1699-0463.1989.tb00452.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The molecular basis of antibiotic resistance was studied in 32 epidemiologically unrelated Danish clinical isolates of Haemophilus influenzae. Both non-encapsulated and capsulated type b strains were represented as well as four different biotypes. Plasmid DNA was found in 11 strains, all of which were antibiotic resistant. Antibiotic resistance was transferred to an Rd Haemophilus influenzae recipient from 5 of 6 prospective donors. Ampicillin and chloramphenicol resistance were linked markers while tetracycline resistance--when unselected--was lost in 18% of the transconjugants. Loss of Tcr was associated with loss of a plasmid DNA segment. Restriction enzyme profiles of plasmid DNA lead to the conclusion that the drug resistance plasmids are derivatives of a common, not too distant, ancestor. There is evidence of both clonal spread and horizontal transmission of related drug resistance plasmids in H. influenzae in Denmark.
Collapse
Affiliation(s)
- S T Jørgensen
- Department of Microbiology, Royal Veterinary and Agricultural University, Copenhagen, Denmark
| | | | | | | |
Collapse
|
19
|
Walter RB, Stuy JH. Isolation and characterization of a UV-sensitive mutator (mutB1) mutant of Haemophilus influenzae. J Bacteriol 1988; 170:2537-42. [PMID: 3259573 PMCID: PMC211168 DOI: 10.1128/jb.170.6.2537-2542.1988] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The mutB1 mutant of Haemophilus influenzae is very sensitive to UV radiation but only slightly sensitive to methylmethane sulfonate or N-methyl-N'-nitro-N-nitrosoguanidine. Cultures of mutB1 cells contain high numbers of spontaneous mutants and show hypermutability after exposure to the latter mutagen. Normally high-efficiency transforming markers, as well as low-efficiency ones, transform mutB1 recipients at similarly low efficiencies. Significant host cell reactivation was observed when mutB1 cells were exposed to UV-damaged phage; however, these mutants showed a decrease in phage recombination. This mutant did not degrade its DNA following exposure to UV. It is speculated that the mutB1 mutation is similar to the Escherichia coli uvrD mutation.
Collapse
Affiliation(s)
- R B Walter
- The University of Texas System Cancer Center, Science Park-Research Division, Smithville 78957
| | | |
Collapse
|
20
|
Abstract
Ampicillin resistance was first reported among clinical isolates of Haemophilus influenzae in 1972. Reports of chloramphenicol resistance followed shortly thereafter. The principal mechanism of resistance to these two antibiotics is enzymatic. Although other mechanisms have been described, they are found in comparatively few strains. The genetic information for the inactivating enzymes is plasmid mediated and therefore readily transmissible to susceptible strains. Consequently, effective therapy for invasive disease caused by this pathogen has been seriously compromised. As antibiotic susceptibility became less predictable, in vitro testing became increasingly important. Unfortunately, the standardization of methods for laboratory testing has been slow and complicated by the fastidious nature of the organisms. This review traces the development of antibiotic resistance in H. influenzae, discusses the mechanisms which appear to be important in mediating resistance, explores newer antimicrobial agents which might be useful in the treatment of infection, and analyzes the various approaches to in vitro testing.
Collapse
Affiliation(s)
- C A Needham
- Department of Laboratory Medicine, Lahey Clinic Medical Center, Burlington, Massachusetts 01805
| |
Collapse
|
21
|
Deich RA, Green BA. Mobilization of Haemophilus influenzae chromosomal markers by an Escherichia coli F' factor. J Bacteriol 1987; 169:1905-10. [PMID: 3032900 PMCID: PMC212043 DOI: 10.1128/jb.169.5.1905-1910.1987] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Filter matings between E. coli K-12 strains carrying an F'::Tn5,Tn9 factor with H. influenzae Rd strains gave rise to kanamycin-chloramphenicol-resistant H. influenzae strains at a frequency of approximately 10(-6). Transfer of the F' factor to H. influenzae was verified by expression of unselected markers in H. influenzae (lac+ or cotransfer of the nonselected antibiotic resistance), physical presence of a high-molecular-weight plasmid in recipient H. influenzae cells, and detection by Southern hybridization analysis of DNA sequences specific for the F' factor replication and partition functions in recipient H. influenzae cells. H. influenzae (F' Tn5,Tn9) strains were capable of transferring kanamycin and chloramphenicol resistances to other H. influenzae strains and were capable of mobilizing H. influenzae chromosomal markers at a low frequency. Insertion of a Tn5 element in the H. influenzae genome near the novobiocin resistance gene increased the frequency of transfer of novobiocin resistance about 30-fold. Transfer of other chromosomal markers also increased, although to a lesser extent, and ordered transfer of chromosomal markers could be demonstrated. Gene transfer was insensitive to DNase I, and transfer of chromosomal (but not F' factor) markers was dependent on the H. influenzae rec-1 and rec-2 gene functions.
Collapse
|
22
|
Pifer ML. Plasmid establishment in competent Haemophilus influenzae occurs by illegitimate transformation. J Bacteriol 1986; 168:683-7. [PMID: 3491064 PMCID: PMC213535 DOI: 10.1128/jb.168.2.683-687.1986] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Establishment of plasmids in naturally competent Haemophilus influenzae is incompatible with transformation via the normal DNA translocation pathways. Instead, establishing plasmids appear to evade the degradation which ordinarily accompanies translocation, arriving as intact double-stranded molecules in the cytoplasm. Evidence is presented that plasmid establishment is a rare illegitimate transformation event which resembles artificial transformation. This process is compared with plasmid marker rescue transformation, and a method for greatly increasing establishment frequency is described.
Collapse
|
23
|
Stuy JH, Walter RB. Homology-facilitated plasmid transfer in Haemophilus influenzae. MOLECULAR & GENERAL GENETICS : MGG 1986; 203:288-95. [PMID: 3016481 DOI: 10.1007/bf00333968] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The 8 kbp plasmid pAT4 transformed Haemophilus influenzae Rd cells at low frequencies. Transformation was increased up to 100 times, however, when the recipient cells carried a DNA segment in either their chromosome or in a resident plasmid that was homologous to at least part of plasmid pAT4. Linearized plasmid DNA molecules did not transform cells without DNA homology; they efficiently transformed homology recipients, but only when the cuts had been made in the region of shared homology. In most cases examined the circular donor plasmid had been reconstituted from the transforming DNA; in some cases the reconstituted plasmid carried a mutation initially present in the recipient chromosome, provided the transforming plasmid had been linearized in the region of shared homology. Plasmid reconstitution was not observed in recA1 cells. We conclude that homology-facilitated plasmid transformation (transfer) is similar to that reported for Bacillus subtilis and Streptococcus pneumoniae.
Collapse
|
24
|
Piffaretti JC, Camponovo T, Borer-Bigliardi B, Arini A. A novel type of resistance plasmid in Haemophilus influenzae. Antimicrob Agents Chemother 1986; 29:511-4. [PMID: 3013086 PMCID: PMC180424 DOI: 10.1128/aac.29.3.511] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Resistance plasmids of a novel type were found in two Haemophilus influenzae clinical isolates. pPJ301 and pPJ302 are 10.0 kilobases in size, carry a Tn2-like transposable element, and are related only by their common beta-lactamase genes to the other two types of resistance plasmids known to occur in H. influenzae.
Collapse
|
25
|
Abstract
Different Haemophilus cultures were mixed and then spotted onto an agar plate. These mixed colonies were incubated at 37 degrees C and then scored for the presence of recombinants. It was found that conjugative plasmids transferred very efficiently and quickly under these conditions, but only between cells of the same species. Four small plasmids did not transfer at all, nor were they mobilized by the two conjugative plasmids studied. Chromosomal markers transferred very inefficiently. The evidence favored transfer by genetic transformation rather than by conjugation. When mixed cultures were inoculated into broth and then incubated, the transfer of conjugative plasmids was not observed. Transfer of chromosomal markers occurred only when the media used contained Eugonbroth in addition to brain heart infusion, and even then it was very inefficient. The addition of DNase completely eliminated such transfers. This and other evidence indicate that in cell suspensions, chromosomal marker transfer also occurs through transformation. A corrected map of several genetic markers is presented.
Collapse
|
26
|
Pintado C, Salvador C, Rotger R, Nombela C. Multiresistance plasmid from commensal Neisseria strains. Antimicrob Agents Chemother 1985; 27:120-4. [PMID: 3885843 PMCID: PMC176216 DOI: 10.1128/aac.27.1.120] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Antibiotic-resistant commensal strains of Neisseria spp. and Branhamella catarrhalis were isolated from throat cultures, on the basis of their capacity to grow in the presence of penicillin, streptomycin, or sulfamethoxazole-trimethoprim. Several strains, which belonged to different species of Neisseria, were resistant to beta-lactams, streptomycin, sulfamethoxazole, and trimethoprim, harbored a 6.0-megadalton plasmid with identical HinfI restriction patterns, and produced beta-lactamase and streptomycin phosphotransferase. The resistance determinants for beta-lactams, streptomycin, and sulfamethoxazole, but not for trimethoprim, were transferred from all these strains to Escherichia coli by conjugation or transformation. The resulting transconjugants or transformants acquired the plasmid and the capacity to produce beta-lactamase and streptomycin phosphotransferase. The 6.0-megadalton plasmid complemented a mutation which determines production of thermosensitive dihydropteroate synthetase in E. coli. We conclude that an R plasmid coding for beta-lactamase, streptomycin phosphotransferase, and a sulfonamide-resistant dihydropteroate synthetase is common to these strains.
Collapse
|
27
|
Balganesh M, Setlow JK. Differential behavior of plasmids containing chromosomal DNA insertions of various sizes during transformation and conjugation in Haemophilus influenzae. J Bacteriol 1985; 161:141-6. [PMID: 3871435 PMCID: PMC214847 DOI: 10.1128/jb.161.1.141-146.1985] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Plasmids with chromosomal insertions were constructed by removal of a 1.1-kilobase-pair piece from the 9.8-kilobase-pair vector plasmid pDM2 by EcoRI digestion and inserting in its place various lengths of chromosomal DNA (1.7, 3.4, and 9.0 kilobase pairs) coding for resistance to novobiocin. A fourth plasmid was constructed by insertion of the largest piece of chromosomal DNA into the SmaI site of pDM2. The plasmids without inserts were taken up poorly by competent cells and thus were considered not to contain specific DNA uptake sites. The presence of even the smallest insert of chromosomal DNA caused a large increase in transformation of Rec+ and Rec- strains. The frequency of plasmid establishment in Rec+ cells by transformation increased exponentially with increasing insert size, but in Rec- cells there was less transformation by the larger plasmids. Conjugal transfer of these plasmids was carried out with the 35-kilobase-pair mobilizing plasmid pHD147. The frequency of establishment of plasmids by this method not only was not markedly affected by the presence of the insertions, but also decreased somewhat with increase in insert size and was independent of rec-1 and rec-2 genes. Recombination between plasmid and chromosome was readily detected after transformation, but could not be detected after transconjugation even when the recipient cells were Rec+ and made competent. These data suggested that there is a special processing of plasmid DNA that enters the competent cells in transformation that makes possible recombination of homologous regions of the plasmid with the chromosome and pairing with the chromosome that aids plasmid establishment.
Collapse
|
28
|
Murphey-Corb M, Nolan-Willard M, Daum RS. Integration of plasmid DNA coding for beta-lactamase production in the Haemophilus influenzae chromosome. J Bacteriol 1984; 160:815-7. [PMID: 6094493 PMCID: PMC214815 DOI: 10.1128/jb.160.2.815-817.1984] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Of beta-lactamase-producing strains of Haemophilus influenzae, 65% do not contain extrachromosomal plasmid DNA. These strains, however, conjugally transfer beta-lactamase production to a recipient strain from which a 30-megadalton plasmid can be isolated. Restriction enzyme analysis and Southern transfer of DNA from both donor and recipient strains revealed that chromosomal integration of plasmid sequences occurred in all donor strains examined.
Collapse
|
29
|
George RC, Broadbent DA, Drasar BS. The effect of influenza virus on the adherence of Haemophilus influenzae to human cells in tissue culture. BRITISH JOURNAL OF EXPERIMENTAL PATHOLOGY 1983; 64:655-9. [PMID: 6607064 PMCID: PMC2040844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The adherence of eleven strains of Haemophilus influenzae to MRC5 cells was studied and compared with adherence of the same eleven strains to MRC5 cells infected with influenza A/NWS/33 virus. Per cent Adhesion (the proportion of cells to which more than two bacteria were adhering) was estimated. Organisms grown on solid media adhered better than those grown in liquid media though the difference was not statistically significant (t test for independent means). A wide range of % Adhesion values for organisms grown on solid media to control cells was exhibited (1-88%). Ten of eleven strains grown on solid media or in broth showed increased adherence to influenza virus infected cells; this difference was significant (P less than 0.05, t test for independent means). The effect of virus infection in increasing % Adhesion was inversely proportional to the adhesiveness of the strain in question to uninfected cells. Strains that adhered most efficiently to control cells showed little increase in % Adhesion following virus infection, while strains that adhered poorly to control cells showed large increases in % Adhesion following virus infection.
Collapse
|
30
|
Antimicrobial resistance. Bull World Health Organ 1983; 61:383-94. [PMID: 6603914 PMCID: PMC2536104] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The development of antimicrobial drugs, and particularly of antibiotics, has played a considerable role in substantially reducing the morbidity and mortality rates of many infectious diseases. However, the fact that bacteria can develop resistance to antibiotics has produced a situation where antimicrobial agents are losing their effectiveness because of the spread and persistence of drug-resistant organisms. To combat this, more and more antibiotics with increased therapeutic and prophylactic action will need to be developed.This article is concerned with antibiotic resistance in bacteria which are pathogenic to man and animals. The historical background is given, as well as some information on the present situation and trends of antibiotic resistance to certain bacteria in different parts of the world. Considerable concern is raised over the use of antibiotics in man and animals. It is stated that antibiotic resistance in human pathogens is widely attributed to the "misuse" of antibiotics for treatment and prophylaxis in man and to the administration of antibiotics to animals for a variety of purposes (growth promotion, prophylaxis, or therapy), leading to the accumulation of resistant bacteria in their flora. Factors favouring the development of resistance are discussed.
Collapse
|
31
|
[Resistance to antimicrobial agents. A WHO Scientific Working Group]. Bull World Health Organ 1983; 61:583-95. [PMID: 6354504 PMCID: PMC2536137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
|
32
|
Albritton WL, Setlow JK, Slaney L. Transfer of Haemophilus influenzae chromosomal genes by cell-to-cell contact. J Bacteriol 1982; 152:1066-70. [PMID: 6982895 PMCID: PMC221610 DOI: 10.1128/jb.152.3.1066-1070.1982] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
A low-frequency exchange of chromosomal markers was observed in matings of Haemophilus influenzae. Transfer did not appear to be due to classical transformation or to be plasmid mediated, and chromosomal gene transfer differed in several respects from plasmid transfer by conjugation.
Collapse
|
33
|
Abstract
A broad-host-range cloning vector, pUI81, was constructed in vitro from plasmids RSF1010 and pSL25 (a pBR322 derivative) and used to assay for transformation in Rhodopseudomonas sphaeroides. Washing cells with 500 mM Tris was an effective means of inducing competence for DNA uptake. Transformation frequencies as high as 10(-5) (transformants per viable cell) have been achieved by incubating Tris-treated cells with plasmid DNA, 100 mM CaCl2, and 20% polyethylene glycol 6000. Maximum frequencies were obtained when recipient cells were spread onto selective media after a 6.5-h outgrowth period in antibiotic-free medium. The structure (open circular versus closed, covalent circular), size, and concentration of plasmid DNA all significantly affected the transformation frequency. Four different plasmids, all small and suitable as cloning vectors, have been introduced by transformation into several different R. sphaeroides strains. Recombinant DNA carried on small, nonconjugative plasmids with broad host ranges can now be directly transferred to R. sphaeroides by this method.
Collapse
|
34
|
Scheifele DW, Fussell SJ, Roberts MC. Characterization of ampicillin-resistant Haemophilus parainfluenzae. Antimicrob Agents Chemother 1982; 21:734-9. [PMID: 6980626 PMCID: PMC182003 DOI: 10.1128/aac.21.5.734] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Carriage of ampicillin-resistant (Ampr) Haemophilus parainfluenzae has become frequent among children in our community, although carriage of Ampr Haemophilus influenzae remains uncommon. In this study we characterized the mechanism of ampicillin resistance in 27 representative isolates of H. parainfluenzae. As determined by isoelectric focusing, each isolate had a TEM-1 beta-lactamase; substrate profiles assessed for enzymes from 10 strains were also consistent with TEM-1 enzyme. Agarose gel electrophoresis revealed a plasmid of 23 to 34 megadaltons in each isolate and a small plasmid (less than or equal to 4 megadaltons) in 14 isolates. Transfer of ampicillin resistance to H. influenzae Rd was achieved during membrane mating with 14 of 15 donors. The transconjugants exhibited high-level ampicillin resistance (greater than or equal to 50 micrograms/ml), which was stable despite serial passage of isolates on antibiotic-free media. The transconjugants tested retained fertility. Cryptic plasmids were discovered in 7 of 25 antibiotic-susceptible H. parainfluenzae isolates. Our data suggest that H. parainfluenzae may play an important role in the exchange of Ampr genes among throat bacteria.
Collapse
|
35
|
Rashtchian A, Dubes GR, Booth SJ. Tetracycline-inducible transfer of tetracycline resistance in Bacteroides fragilis in the absence of detectable plasmid DNA. J Bacteriol 1982; 150:141-7. [PMID: 7061390 PMCID: PMC220092 DOI: 10.1128/jb.150.1.141-147.1982] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Tetracycline resistance of three Bacteroides fragilis strains was shown to be inducible by subinhibitory concentrations of tetracycline. Tetracycline resistance markers could be transferred to another B. fragilis strain by filter mating. The transferability was inducible by subinhibitory concentrations of tetracycline and did not take place in the absence of tetracycline. The optimum concentration of tetracycline for induction of transfer was about 2 microgram/ml. The transfer was shown to be a conjugation-like process requiring cell-to-cell contact between donor and recipient. Screening of parental donor strains for the presence of plasmid DNA did not demonstrate any detectable plasmids in two of the strains. A 3.0-megadalton plasmid, designated pBY5, was present in the third donor strain. Mobilization of pBY5 by another plasmid (pBF4) showed that pBY5 did not carry the genes responsible for tetracycline resistance. It appears that the genes responsible for resistance to tetracycline as well as those responsible for conjugal transfer may be carried on the chromosome in all three donor strains.
Collapse
|
36
|
Danner DB, Pifer ML. Plasmid cloning vectors resistant to ampicillin and tetracycline which can replicate in both E. coli and Haemophilus cells. Gene X 1982; 18:101-5. [PMID: 6286414 DOI: 10.1016/0378-1119(82)90062-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We have constructed two plasmid vectors, pHCV5 and pHVTl, which will replicate both in Haemophilus and in Escherichia coli. Both contain the ampicillin-resistance gene and the replication origin from a Haemophilus plasmid, pRSF0885. Both also contain the pBR322 origin and therefore can be amplified in E. coli by chloramphenicol treatment. The plasmid pHCV5 contains the tetracycline-resistance gene of pBR322, and pHVT1 contains the analogous region from the transposon Tn10.
Collapse
|
37
|
Deneer HG, Slaney L, Maclean IW, Albritton WL. Mobilization of nonconjugative antibiotic resistance plasmids in Haemophilus ducreyi. J Bacteriol 1982; 149:726-32. [PMID: 6276368 PMCID: PMC216565 DOI: 10.1128/jb.149.2.726-732.1982] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A clinical isolate of Haemophilus ducreyi was found to harbor three plasmids: a 23.5-megadalton (Mdal) phenotypically cryptic plasmid, a 7.0-Mdal ampicillin resistance plasmid, and a 4.0-Mdal sulfonamide resistance plasmid. The two smaller plasmids were transferable by conjugation to Haemophilus recipients, but only if the donor cell harbored the 23.5-Mdal plasmid as well, indicating that this large plasmid had mobilizing capabilities. Transfer was also possible to Escherichia coli recipients. Haemophilus influenzae transconjugants which had acquired both the 23.5-Mdal plasmid and one of the R-plasmids could subsequently retransfer the R-plasmid to other Haemophilus recipients at higher frequencies. A derivative of the 23.5 Mdal plasmid was isolated which was shown by restriction endonuclease analysis to contain an ampicillin resistance transposon and to have retained its conjugative ability.
Collapse
|
38
|
Notani NK, Setlow JK, McCarthy D, Clayton NL. Transformation of Haemophilus influenzae by plasmid RSF0885. J Bacteriol 1981; 148:812-6. [PMID: 6975775 PMCID: PMC216279 DOI: 10.1128/jb.148.3.812-816.1981] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Plasmid RSF0885, which conferred ampicillin resistance, transformed competent Haemophilus influenzae cells with low efficiency (maximum, less than 0.01%). As judged by competition experiments and uptake of radioactivity, plasmid RSF0885 deoxyribonucleic acid was taken up into competent H. influenzae cells several orders of magnitude less efficiently than H. influenzae chromosomal deoxyribonucleic acid. Plasmid RSF0885 transformed cells with even lower efficiency than could be accounted for by the low uptake. Transformation was not affected by rec-1 and rec-2 mutations in the recipient, and strains cured of the plasmid did not show increased transformation. Plasmid molecules cut once with a restriction enzyme that made blunt ends did not transform. Transformation was favored by the closed circular form of the plasmid.
Collapse
|
39
|
Stuy JH, Walter RB. Addition, deletion, and substitution of long nonhomologous deoxyribonucleic acid segments by genetic transformation of Haemophilus influenzae. J Bacteriol 1981; 148:565-71. [PMID: 6975273 PMCID: PMC216241 DOI: 10.1128/jb.148.2.565-571.1981] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
A complete EcoRI digest of Haemophilus influenzae phage HP1 deoxyribonucleic acid (DNA) was mixed with incomplete digests of various H. influenzae R plasmids, sealed with T4 ligase, and transformed into an HP1 lysogen. Most of the chloramphenicol- and tetracycline-resistant transformants did not produce phage although they possessed all the phage genes examined. They also did not transfer antibiotic resistance by conjugation. DNA lysates from them transformed other lysogens to resistance and to loss of phage production at different but quite high frequencies (addition of long DNA segments). They themselves could be transformed efficiently to strains with a wild prophage (deletion of long DNA segments). It was concluded that lysogenic cultures had been constructed with various DNA inserts in their prophages carrying antibiotic resistance genes from the R plasmids. The site of insertion was determined by genetic crosses. DNAs with inserts that transferred with lower efficiency were more sensitive to ultraviolet radiation. This supports the view that insert transfer efficiencies reflect the sizes of the insert.
Collapse
|
40
|
Bell SM, Plowman DE, Burville LJ, Mayall BC. Genetic variation that switches off and on beta-lactamase production by Haemophilus influenzae. Lancet 1981; 1:846. [PMID: 6111711 DOI: 10.1016/s0140-6736(81)92729-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
41
|
Abstract
Purified 34-megadalton-plasmid deoxyribonucleic acid from antibiotic-resistant strains of Haemophilus influenzae transforms competent strains of H. influenzae more efficiently if the recipient strains contain certain other 30-megadalton plasmids.
Collapse
|
42
|
Abstract
Transforming deoxyribonucleic acid (DNA) preparations from Haemophilus influenzae Rd strains carrying a chromosomally integrated, conjugative, antibiotic resistance transfer (R) plasmid were exposed to ultraviolet radiation and then assayed for antibiotic resistance transfer on sensitive wild-type Rd competent suspensions and on similar suspensions of a uvr-1 mutant unable to excise pyrimidine dimers. No host cell reactivation of resistance transfer (DNA repair) was observed. Parallel experiments with ethanol-precipitated, heated, free R plasmid DNA preparations gave much higher survival when assayed on the wild-type strain compared to the survival on the uvr-1 strain. These observations indicate that additive genetic transformation (in this case, the addition of the integrated R plasmid to the recipient genome) involves single-strand insertion.
Collapse
|
43
|
Stuy JH. Mechanism of Haemophilus influenzae transfection by single and double prophage deoxyribonucleic acid. J Bacteriol 1980; 144:1003-8. [PMID: 6969255 PMCID: PMC294764 DOI: 10.1128/jb.144.3.1003-1008.1980] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Whole phages HP1 and HP3, vegetative-phage deoxyribonucleic acid (DNA), and single and tandem double prophage DNA were exposed to ultraviolet radiation and then assayed on a wild-type (DNA repair-proficient) Haemophilus influenzae Rd strain and on a repair-deficient uvr-1 strain. Host cell reactivation (DNA repair) was observed for whole-phage and vegetative-phage DNA but not for single and double prophage DNA. Competent (phage-resistant) Haemophilus parainfluenzae cells were normally transfected with H. influenzae-grown phage DNA and with tandem double prophage DNA but not at all with single prophage DNA. CaCl2-treated H. influenzae suspensions could be transfected with vegetative phage DNA and with double prophage DNA but not with single prophage DNA. These observations support the hypothesis that transfection with single prophage DNA occurs through prophage DNA single-strand insertion into the recipient chromosome (at the bacterial att site) followed by DNA replication and then prophage induction.
Collapse
|
44
|
Bagci H, Stuy JH. Bromouracil-induced mutagenesis in a mismatch-repair-deficient strain of Haemophilus influenzae. Mutat Res 1980; 73:15-9. [PMID: 6973085 DOI: 10.1016/0027-5107(80)90131-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Cells of wild-type Haemophilus influenzae and of a mismatch-repair-deficient mutant (hex-) were grown in a chemically defined medium containing either thymidine or 5-bromodeoxyuridine (BUdR). Spontaneous mutation frequencies to resistance against 3 antibiotics observed for the thymidine cultures were 10-30 times higher for the hex- mutant. The mutation frequencies observed for the BUdR hex- culture were increased by another 10 times while those for the wild-type suspension did not differ from the frequencies seen in the thymidine medium.
Collapse
|
45
|
Abstract
Tetracycline at a low concentration stimulated the expression of ampicillin resistance in certain strains of Haemophilus influenzae.
Collapse
|
46
|
Roberts MC, Smith AL. Molecular characterization of "plasmid-free" antibiotic-resistant Haemophilus influenzae. J Bacteriol 1980; 144:476-9. [PMID: 6968310 PMCID: PMC294691 DOI: 10.1128/jb.144.1.476-479.1980] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
We examined 14 multiresistant and 8 ampicillin- or tetracycline-resistant Haemophilus influenzae isolates and 4 ampicillin-resistant H. parainfluenzae isolates for plasmid deoxyribonucleic acid. Sixteen strains carried plasmids. Both "plasmid-free" and plasmid-carrying isolates transferred the antibiotic resistance by conjugation. All transconjugants carried plasmid deoxyribonucleic acid, suggesting that the apparent plasmid-free strains contained R plasmids encoding for antibiotic resistance.
Collapse
|
47
|
Stuy JH. Chromosomally integrated conjugative plasmids are common in antibiotic-resistant Haemophilus influenzae. J Bacteriol 1980; 142:925-30. [PMID: 6966629 PMCID: PMC294118 DOI: 10.1128/jb.142.3.925-930.1980] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Twenty-three highly antibiotic-resistant strains of Haemophilus influenzae and two of Haemophilus parainfluenzae without detectable large plasmids were examined for conjugative transfer of their resistance to H. influenzae strain Rd or to other strains. Very inefficient transfer was observed for 18 H. influenzae strains and 1 H. parainfluenzae strain. All H. influenzae transcipients carried a large plasmid, and they were in turn efficient donors of their resistances in standard conjugation crosses with isogenic recipients. This was not seen for the H. parainfluenzae transcipients. It is concluded that most of the original antibiotic-resistant cultures carried an integrated conjugative R plasmid which had been excised in a few cells in each population. It was these cells which transferred resistance in the primary crosses.
Collapse
|
48
|
Smith MD, Shoemaker NB, Burdett V, Guild WR. Transfer of plasmids by conjugation in Streptococcus pneumonias. Plasmid 1980; 3:70-9. [PMID: 6278525 DOI: 10.1016/s0147-619x(80)90035-9] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
|