Decreased susceptibility to penicillin G and Tet M plasmids in genital and anorectal isolates of Neisseria meningitidis (original) (raw)
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European Journal of Clinical Microbiology & Infectious Diseases, 1993
A random selection of Neisseria rneningitidis strains isolated in Sweden in the period 1981-1990 were investigated for plasmid carriage and susceptibility to antimicrobial agents commonly used for treatment and prophylaxis of meningococcal disease. The MICs were determined by the agar dilution method for penicillin V, penicillin G, rifampicin, sulfadiazine, erythromycin and tetracycline. In 13 % of the invasive strains the MIC of penicillin V was _> 0.5 mg/l which may cause concern regarding the usefulness of penicillin V in prophylaxis. In strains isolated from the urogenital tract the MICs of penicillin V and penicillin G were higher than in the invasive strains. In about 82 % of the strains isolated in 1987-1988 the MIC of tetracycline was >_ 0.5 mg/l whereas no such strains were found in 1981-1982. Plasmids were found in 2 of 119 invasive strains, in I of 50 strains from the respiratory tract and in I of 19 strains from the urogenital tract. The plasmid sizes were L3, 2.6, 25 and 40 Mda. None of these strains were beta-lactamase producing and no relation to a high degree antibiotic resistance was observed. Strains of Neisseria meningilidis are normally susceptible to many of the antibiotics presently used (1), including beta-lactams, rifampicin, chloramphenicol, tetracyclines, quinolones and macrolides. These organisms have an inherent decreased susceptibility to trimethoprim, vancomycin and polymyxin B. The emergence of meningococcal strains resistant to sulphonamides in the USA in the early 1960s (2) served as an example of the unwanted biological side-effects of the use of antimicrobial agents. At present the relative susceptibility of meningococci to sulphonamides is mainly used as an epidemicological marker. Sulphonamides can, however, still be considered for use in prophylaxis of smaller groups of people providing that the invasive index strain is susceptible, i.e. the MIC of sulfadiazine is < 10 mg/l. In the 1980s an increasing number of reports were published of meningococci with decreased susceptibility to penicillin G (MIC > 0.16 mg/l) (3-15). Such strains have been isolated in England and Wales since 1983 (3, 4), in Spain since 1985 (5-12) and in South Africa since 1987 (13).
Memórias do Instituto Oswaldo Cruz, 2001
The susceptibility to penicillin of 111 Neisseria meningitidis strains was assessed by the agar-dilution procedure and serosubtypes were determined by a whole-cell enzyme-linked immunoassay using monoclonal antibodies reagents. Thirty-five isolates showed reduced sensitivity to penicillin (MIC > or = 0.1 mg/l and < or = 1 mg/l) and no resistant strains were detected. The most common phenotype was B:4:P1.15 (77.5%) and a rising trend of non-typeable and non-subtypeable strains was detected. The increase in levels of minimal inhibitory concentrations of meningococci to penicillin gives cause for concern and the increase in non-typeable and non-subtypeable isolation demand the use of molecular biology techniques for their typing.
Journal of Clinical Microbiology, 2003
Sequence analysis of the penA gene, encoding penicillin-binding protein 2 (PBP2), in 30 penicillin-intermediate (PenI) Neisseria meningitidis strains showed altered gene sequences due to the translocation of exogenous DNA blocks derived from commensal neisseriae, which are known to have PBP2 proteins with decreased affinity for the antibiotic. In order to obtain a rapid and reproducible method for predicting the PenI phenotype, a real-time PCR assay was set up with primers and probes designed on the basis of the penA gene. The A→G mutation at codon 566, in the transpeptidase domain of the penA gene (which is present in the whole sample of 30 PenI strains and in all the 41 sequences of PenI meningococci isolated worldwide and has been deposited in the sequence databank), was chosen as a marker of penA translocations. Two hybridization probes were designed to distinguish the wild-type penA gene in penicillin-susceptible (PenS) meningococci from the mutated penA gene at codon 566 in Pe...
Official Journal of the Association of Medical Microbiology and Infectious Disease Canada, 2021
Antimicrobial susceptibility of 50 Neisseria meningitidis strains detected in Nova Scotia between 2004 and 2018 was determined. The isolates were cultured from sites that might prompt chemoprophylaxis (27 blood, 18 cerebrospinal fluid [CSF], 3 CSF–blood, and 2 conjunctiva). Minimal inhibitory concentrations (MICs) were determined to azithromycin, ciprofloxacin, minocycline, rifampin, trimethoprim–sulfamethoxazole, and penicillin G, using a diffusion gradient strip on Mueller–Hinton agar with 5% sheep blood in 5% CO2 for 20–24 hours. All isolates remained susceptible to azithromycin, ciprofloxacin, minocycline, and rifampin, but there was 26% resistance to trimethoprim–sulfamethoxazole. There was a rise in penicillin MIC of the isolates over the study period.
Journal of Clinical Microbiology, 2005
Neisseria meningitidis represents a pathogen of great public health importance in both developed and developing countries. Resistance to some antimicrobial agents used either for therapy of invasive infections or for prophylaxis of case contacts has long been recognized, although specific guidelines for susceptibility testing have not been fully developed. We have examined the susceptibilities of a collection of 442 meningococcal clinical isolates from 15 countries to 16 antimicrobial agents. These included isolates recovered between 1917 and 2004, with representatives of all major serogroups. All isolates were tested by the Clinical and Laboratory Standards Institute (formerly NCCLS) broth microdilution method using Mueller-Hinton lysed horse blood broth, while a subset of 102 isolates was tested by agar dilution using Mueller-Hinton sheep blood agar. Most isolates provided adequate growth for MIC determinations by both broth and agar methods. Growth in broth was enhanced by CO 2 i...
Journal of Clinical Microbiology, 2008
Neisseria meningitidis strains (meningococci) with decreased susceptibility to penicillin (MICs, >0.06 g/ml) have been reported in several parts of the world, but the prevalence of such isolates in Africa is poorly described. Data from an active national laboratory-based surveillance program from January 2001 through December 2005 were analyzed. A total of 1,897 cases of invasive meningococcal disease were reported, with an average annual incidence of 0.83/100,000 population. Of these cases, 1,381 (73%) had viable isolates available for further testing; 87 (6%) of these isolates tested intermediately resistant to penicillin (Pen i ). Pen i meningococcal isolates were distributed throughout all provinces and age groups, and there was no association with outcome or human immunodeficiency virus infection. The prevalence of Pen i was lower in serogroup A (7/295; 2%) than in serogroup B (24/314; 8%), serogroup C (9/117; 8%), serogroup Y (22/248; 9%), or serogroup W135 (25/396; 6%) (P ؍ 0.02). Pulsed-field gel electrophoresis grouped 63/82 Pen i isolates into nine clusters, mostly according to serogroup. The clustering of patterns from Pen i isolates was not different from that of penicillinsusceptible isolates. Twelve sequence types were identified among 18 isolates arbitrarily selected for multilocus sequence typing. DNA sequence analysis of the penA gene identified 26 different alleles among the Pen i isolates. Intermediate penicillin resistance is thus widespread among meningococcal serogroups, has been selected in a variety of lineages, and, to date, does not appear to be associated with increased mortality. This is the first report describing the prevalence and molecular epidemiology of Pen i meningococcal isolates from sub-Saharan Africa.
Antimicrobial Agents and Chemotherapy, 2000
The activities of seven antimicrobial agents used for treatment and prophylaxis of meningococcal disease was investigated against 901 Neisseria meningitidis isolates, 112 of which were recovered from patients and 789 of which were recovered from asymptomatic carriers. The proportions of isolates with decreased susceptibility to penicillin were 55.3 and 39.0%, respectively. Penicillin-and ampicillin-intermediate strains were more common among serogroup C meningococci than among non-serogroup C meningococci from both patients and carriers.
Diagnostic Microbiology and Infectious Disease, 2002
The NCCLS agar dilution method and Etest are currently accepted methods for susceptibility testing of Neisseria meningitidis to penicillin . We determined the MIC of penicillin V and penicillin G by both the agar dilution method and Etest using 43 strains of N. meningitidis . Although results for reference strains were within the accepted quality control range of penicillin MICs for both drugs, differences of two to three dilutions were seen between the two antibiotics with both methods. Penicillin V results cannot correctly predict the susceptibility to penicillin G for N. meningitidis if penicillin G breakpoints are used for penicillin V. However, adjusting the penicillin V breakpoints two dilutions higher (i.e. S 0.25 and R 8 µg/ml), concordance could be achieved for susceptibility categorization by the two compounds. An agreement of 98% 1 dilution was obtained between Etest and the reference method when using penicillin G strips, . We conclude that Etest with penicillin G strips is a convenient and reliable alternative method for determining the MICs of penicillin for N.meningitidis.
Journal of Antimicrobial Chemotherapy, 2001
We studied polymorphism of penA (which encodes penicillin-binding protein 2) in 13 strains of Neisseria meningitidis susceptible to penicillin (pen S ) and 12 strains with reduced susceptibility to penicillin (pen I ). These strains differed in geographical origin. Serological and genetic typing showed that they were highly diverse and belonged to several genetic lineages. Restriction analysis and DNA sequencing of penA showed that all pen S strains had the same penA allele regardless of genetic group, whereas pen I strains harboured various penA alleles. Transformation with amplicons of penA and genomic DNA from several pen I strains conferred the pen I phenotype on a pen S strain. Thus, reduction in susceptibility to penicillin is directly related to changes in penA and analysis of penA polymorphisms could be used as a reliable tool for characterizing meningococcal strains in terms of their susceptibility to penicillin.