Phenotypic and Molecular Characterization of Tetracycline- and Erythromycin-Resistant Strains of Streptococcus pneumoniae

ABSTRACT Sixty-five clinical isolates of Streptococcus pneumoniae, all collected in Italy between 1999 and 2002 and resistant to both tetracycline (MIC, ≥8 μg/ml) and erythromycin (MIC, ≥1 μg/ml), were investigated. Of these strains, 11% were penicillin resistant and 23% were penicillin intermediate. With the use of the erythromycin-clindamycin-rokitamycin triple-disk test, 14 strains were assigned to the constitutive (cMLS) phenotype of macrolide resistance, 44 were assigned to the partially inducible (iMcLS) phenotype, 1 was assigned to the inducible (iMLS) phenotype, and 6 were assigned to the efflux-mediated (M) phenotype. In PCR assays, 64 of the 65 strains were positive for the tetracycline resistance gene tet(M), the exception being the one M isolate susceptible to kanamycin, whereas tet(K), tet(L), and tet(O) were never found. All cMLS, iMcLS, and iMLS isolates had the erythromycin resistance gene erm(B), and all M phenotype isolates had the mef(A) or mef(E) gene. No isolate had the erm(A) gene. The int-Tn gene, encoding the integrase of the Tn916-Tn1545 family of conjugative transposons, was detected in 62 of the 65 test strains. Typing assays showed the strains to be to a great extent unrelated. Of 16 different serotypes detected, the most numerous were 23F (n = 13), 19A (n = 10), 19F (n = 9), 6B (n = 8), and 14 (n = 6). Of 49 different pulsed-field gel electrophoresis types identified, the majority (n = 39) were represented by a single isolate, while the most numerous type included five isolates. By high-resolution restriction analysis of PCR amplicons with four endonucleases, the tet(M) loci from the 64 tet(M)-positive pneumococci were classified into seven distinct restriction types. Overall, a Tn1545-like transposon could reasonably account for tetracycline and erythromycin resistance in the vast majority of the pneumococci of cMLS, iMcLS, and iMLS phenotypes, whereas a Tn916-like transposon could account for tetracycline resistance in most M phenotype strains.

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Characterization of the Tn916-like Transposon Tn3872 in a Strain of Abiotrophia defectiva (Streptococcus defectivus) Causing Sequential Episodes of Endocarditis in a Child

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.3.790-793.2000 ◽

2000 ◽

Vol 44 (3) ◽

pp. 790-793 ◽

Cited By ~ 32

Author(s):

Claire Poyart ◽

Gilles Quesne ◽

Philippe Acar ◽

Patrick Berche ◽

Patrick Trieu-Cuot

Keyword(s):

Antibiotic Resistance ◽

Resistance Gene ◽

Resistance Genes ◽

Tetracycline Resistance ◽

Erythromycin Resistance ◽

Tetracycline Resistance Gene ◽

Conjugative Transposons ◽

Abiotrophia Defectiva

ABSTRACT Clinical blood isolates from three sequential episodes of endocarditis occurring over a 6-month period in a child with a malformative cardiopathy were investigated. All isolates identified asAbiotrophia defectiva were resistant to erythromycin-clindamycin and to tetracycline-minocycline, due to the presence of sequences homologous to the erythromycin resistance geneermB and to the tetracycline resistance genetet(M), respectively. These resistance genes were located on a chromosomally borne composite Tn916-related transposon. These results demonstrate the involvement of conjugative transposons in the dissemination of antibiotic resistance in the genusAbiotrophia.

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Characterization Of Tetracycline Resistance Of Salmonella Enterica Subspecies Enterica Serovar Infantis Isolated From Poultry In The Northern Part Of Serbia

Acta veterinaria ◽

10.1515/acve-2015-0046 ◽

2015 ◽

Vol 65 (4) ◽

pp. 548-556 ◽

Cited By ~ 1

Author(s):

Dalibor Todorović ◽

Maja Velhner ◽

Dubravka Milanov ◽

Dejan Vidanović ◽

Ljiljana Suvajdžić ◽

...

Keyword(s):

Nalidixic Acid ◽

Inhibitory Concentration ◽

Tetracycline Resistance ◽

Conjugative Plasmid ◽

Gene Encoding ◽

Conjugative Transposons ◽

Poultry Farms ◽

Autonomous Province ◽

Poultry Farming

AbstractResistance to tetracycline was studied inSalmonellaInfantis isolated from 28 poultry farms in the Northern part of Serbia (The Autonomous Province of Vojvodina). A total of 18 isolates were resistant to nalidixic acid (NAL) and tetracycline (TET). The minimal inhibitory concentration (MIC) to TET, ranged from 1-256 mg/L. Namely, 13 isolates exhibited MIC to TET at 256 mg/L, in four of the isolates, the MIC was 128 mg/L and one isolate had MIC 64 mg/L. Ten isolates were exhibiting a MIC of 1mg/L. It was evident thatSalmonellaInfantis had also spread to breeders and layers. In this work, we detected thetetAgene and the correspondingtetRgene (encoding the repressor protein) as well as the truncated transposon Tn1721,which are responsible for the resistance to TET. The presence of the non conjugative transposons from the conjugative plasmid has facilitated the spread of resistance to TET inSalmonella. It was concluded that higher biosecurity practice in poultry farming presents the best option to eliminate infections caused bySalmonellaspp. from poultry flocks in Serbia. A rational use of antimicrobials is necessary to prevent any further spread ofSalmonellaInfantis resistant clones.

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Characterization of a Genetic Element Carrying the Macrolide Efflux Gene mef(A) in Streptococcus pneumoniae

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.44.9.2585-2587.2000 ◽

2000 ◽

Vol 44 (9) ◽

pp. 2585-2587 ◽

Cited By ~ 93

Author(s):

Maria Santagati ◽

Francesco Iannelli ◽

Marco R. Oggioni ◽

Stefania Stefani ◽

Gianni Pozzi

Keyword(s):

Streptococcus Pneumoniae ◽

Resistance Gene ◽

Clinical Isolate ◽

Open Reading Frames ◽

Genetic Element ◽

Reading Frames

ABSTRACT The mef(A) gene from a clinical isolate ofStreptococcus pneumoniae exhibiting the M-type resistance to macrolides was found to be part of the 7,244-bp chromosomal element Tn1207.1, which contained 8 open reading frames.orf2 encodes a resolvase/invertase, and orf5 is a homolog of the macrolide-streptogramin B resistance genemsr(SA).

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Clonal Diversity and Resistance Mechanisms in Tetracycline-Nonsusceptible Streptococcus pneumoniae Isolates in Poland

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01384-06 ◽

2007 ◽

Vol 51 (4) ◽

pp. 1155-1163 ◽

Cited By ~ 17

Author(s):

Radosław Izdebski ◽

Ewa Sadowy ◽

Janusz Fiett ◽

Paweł Grzesiowski ◽

Marek Gniadkowski ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Tetracycline Resistance ◽

Clonal Diversity ◽

Resistance Mechanisms ◽

Pfge Type ◽

Cross Resistance ◽

M Gene ◽

Conjugative Transposons ◽

Tetracycline Resistance Genes ◽

Resistance Determinants

ABSTRACT The frequency of tetracycline resistance in Streptococcus pneumoniae isolates in Poland is one of the highest in Europe. The aim of this study was to analyze the clonal diversity and resistance determinants of tetracycline-nonsusceptible S. pneumoniae isolates identified in Poland and to investigate the effect of tetracycline resistance on their susceptibilities to tigecycline, doxycycline, and minocycline. We have analyzed 866 pneumococcal isolates collected from 1998 to 2003 from patients with respiratory tract diseases, and 242 of these (27.9%) were found to be resistant to tetracycline. All of the resistant isolates were characterized by testing of their susceptibilities to other antimicrobials, serotyping, pulsed-field gel electrophoresis (PFGE), and identification of tetracycline resistance genes and transposons. Selected isolates representing the main PFGE types were analyzed by multilocus sequence typing. Among the isolates investigated, 27 serotypes and 146 various PFGE patterns, grouped into 90 types, were discerned. The most common PFGE type, corresponding to serotype 19F and sequence type 423, was represented by 22.3% of all of the tetracycline-resistant isolates. The tet(M) gene was the sole resistance gene in the group of isolates studied, and in over 96% of the isolates, the Tn916 family of tet(M)-containing conjugative transposons was detected. Several isolates contained specific variants of the transposons, the Tn1545-like, Tn3872-like, or Tn2009-like element. The correlation between the MICs of tetracycline, doxycycline, and minocycline was revealed, whereas no cross-resistance to tetracycline and tigecycline was observed.

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Heterogeneity of Tn5253-Like Composite Elements in ClinicalStreptococcus pneumoniaeIsolates

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01087-10 ◽

2011 ◽

Vol 55 (4) ◽

pp. 1453-1459 ◽

Cited By ~ 21

Author(s):

Marina Mingoia ◽

Emily Tili ◽

Esther Manso ◽

Pietro E. Varaldo ◽

Maria Pia Montanari

Keyword(s):

Tetracycline Resistance ◽

Erythromycin Resistance ◽

Integrase Gene ◽

Chloramphenicol Resistance ◽

Site Specific ◽

Considerable Heterogeneity ◽

Genetic Elements ◽

Conjugative Transposons ◽

Composite Element ◽

Cell Genome

ABSTRACTSeveral drug resistances inStreptococcus pneumoniaeare associated with mobile genetic elements, which are loosely subdivided into a group of smaller (18- to 27-kb) and a group of larger (>50-kb) elements. While the elements of the former group, which typically carry the tetracycline resistance determinanttet(M) and whose prototype is Tn916(18 kb), have been studied extensively, the larger elements, whose prototype is Tn5253(∼65.5 kb), are not as well explored. Tn5253is a composite structure consisting of two independent conjugative transposons, Tn5251(which is virtually identical to Tn916) and Tn5252(∼47.5 kb), with the former inserted into the latter. Tn5252, which so far has only partially been sequenced, carries an integrase gene, driving its site-specific insertion into the host cell genome, and the chloramphenicol resistancecatpC194determinant. This study investigated 20 clinical isolates ofS. pneumoniae, which were selected on the basis ofcatpC194-mediated chloramphenicol resistance. All 20 isolates harbored a Tn5253-like element. The composite elements (some of which have been completely sequenced) demonstrated considerable heterogeneity that stemmed from a dual variability: in the Tn5252-like element, due primarily to differences in the integrase gene but also to differences in cargo genes and in the overall genetic organization, and in the Tn916-like element, with the possible involvement, besides Tn916, of a number of Tn916family pneumococcal elements carrying different erythromycin resistance genes. In mating experiments, only one composite element, containing a less typical Tn916family element, appeared to be nonmobile. Being part of a Tn5253-like composite element may confer on some Tn916-like transposons, which are apparently nontransferable as independent genetic elements, the ability to be mobilized.

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Characterization of a new class of tetracycline-resistance gene tet(S) in Listeria monocytogenes BM4210

Gene ◽

10.1016/0378-1119(93)90665-p ◽

1993 ◽

Vol 131 (1) ◽

pp. 27-34 ◽

Cited By ~ 60

Author(s):

Emmanuelle Charpentier ◽

Guy Gerbaud ◽

Patrice Courvalin

Keyword(s):

Listeria Monocytogenes ◽

Resistance Gene ◽

Tetracycline Resistance ◽

Tetracycline Resistance Gene ◽

New Class

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Molecular Characterization of Pneumococci with Efflux-Mediated Erythromycin Resistance and Identification of a Novel mef Gene Subclass, mef(I)

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.49.12.4999-5006.2005 ◽

2005 ◽

Vol 49 (12) ◽

pp. 4999-5006 ◽

Cited By ~ 41

Author(s):

Ileana Cochetti ◽

Manuela Vecchi ◽

Marina Mingoia ◽

Emily Tili ◽

Maria R. Catania ◽

...

Keyword(s):

Tetracycline Resistance ◽

Sequence Type ◽

Open Reading Frames ◽

Resistant Isolate ◽

Pfge Type ◽

Polymorphism Analysis ◽

Erythromycin Resistance ◽

M Gene ◽

Sequence Types

ABSTRACT The molecular genetics of macrolide resistance were analyzed in 49 clinical pneumococci (including an “atypical” bile-insoluble strain currently assigned to the new species Streptococcus pseudopneumoniae) with efflux-mediated erythromycin resistance (M phenotype). All test strains had the mef gene, identified as mef(A) in 30 isolates and mef(E) in 19 isolates (including the S. pseudopneumoniae strain) on the basis of PCR-restriction fragment length polymorphism analysis. Twenty-eight of the 30 mef(A) isolates shared a pulsed-field gel electrophoresis (PFGE) type corresponding to the England14-9 clone. Of those isolates, 27 (20 belonging to serotype 14) yielded multilocus sequence type ST9, and one isolate yielded a new sequence type. The remaining two mef(A) isolates had different PFGE types and yielded an ST9 type and a new sequence type. Far greater heterogeneity was displayed by the 19 mef(E) isolates, which fell into 11 PFGE types, 12 serotypes (though not serotype 14), and 12 sequence types (including two new ones and an undetermined type for the S. pseudopneumoniae strain). In all mef(A) pneumococci, the mef element was a regular Tn1207.1 transposon, whereas of the mef(E) isolates, 17 carried the mega element and 2 exhibited a previously unreported organization, with no PCR evidence of the other open reading frames of mega. The mef gene of these two isolates, which did not match with the mef(E) gene of the mega element (93.6% homology) and which exhibited comparable homology (91.4%) to the mef(A) gene of the Tn1207.1 transposon, was identified as a novel mef gene variant and was designated mef(I). While penicillin-nonsusceptible isolates (three resistant isolates and one intermediate isolate) were all mef(E) strains, tetracycline resistance was also detected in three mef(A) isolates, due to the tet(M) gene carried by a Tn916-like transposon. A similar mechanism accounted for resistance in four of the five tetracycline-resistant isolates carrying mef(E), in three of which mega was inserted in the Tn916-like transposon, giving rise to the composite element Tn2009. In the fifth mef(E)-positive tetracycline-resistant isolate (the S. pseudopneumoniae strain), tetracycline resistance was due to the presence of the tet(O) gene, apparently unlinked to mef(E).

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The Emergence of Invasive Streptococcus pneumoniae Serotype 24F in Lebanon: Complete Genome Sequencing Reveals High Virulence and Antimicrobial Resistance Characteristics

Frontiers in Microbiology ◽

10.3389/fmicb.2021.637813 ◽

2021 ◽

Vol 12 ◽

Author(s):

Lina Reslan ◽

Marc Finianos ◽

Ibrahim Bitar ◽

Mohamad Bahij Moumneh ◽

George F. Araj ◽

...

Keyword(s):

Streptococcus Pneumoniae ◽

Antimicrobial Resistance ◽

Tetracycline Resistance ◽

Virulence Gene ◽

Surveillance Program ◽

Virulence Determinants ◽

Tetracycline Resistance Genes ◽

Long Reads ◽

Genomic Characterization

BackgroundInvasive pneumococcal disease (IPD) remains a global health problem. IPD incidence has significantly decreased by the use of pneumococcal conjugate vaccines (PCV). Nevertheless, non-PCV serotypes remain a matter of concern. Eight Streptococcus pneumoniae serotype 24F isolates, belonging to a non-PCV serotype, were detected through the Lebanese Inter-Hospital Pneumococcal Surveillance Program. The aim of the study is to characterize phenotypic and genomic features of the 24F isolates in Lebanon.MethodsWGS using long reads sequencing (PacBio) was performed to produce complete circular genomes and to determine clonality, antimicrobial resistance and virulence determinants.ResultsThe sequencing results yielded eight closed circular genomes. Three multilocus sequence typing (MLST) types were identified (ST11618, ST14184, ST15253). Both MLST and WGS analyses revealed that these isolates from Lebanon were genetically homogenous belonging to clonal complex CC230 and clustered closely with isolates originating from Canada, United States of America, United Kingdom and Iceland. Their penicillin binding protein profiles correlated with both β-lactam susceptibility patterns and MLST types. Moreover, the isolates harbored the macrolide and tetracycline resistance genes and showed a similar virulence gene profile. To our knowledge, this study represents the first report of complete phenotypic and genomic characterization of the emerging Streptococcus pneumoniae, serotype 24F, in the Middle East and North Africa region.

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