Serotypes and Patterns of Antibiotic Resistance in Strains Causing Invasive Pneumococcal Disease in Children Less than 5 Years of Age

Objective

The serotypes and patterns of antibiotic resistance of Streptococcus pneumoniae (S. pneumoniae) strains that cause invasive pneumococcal disease (IPD) in infants were analyzed to provide guidance for clinical disease prevention and treatment.

Methods

The clinical features of confirmed IPD were evaluated in 61 patients, less than 5 years of age, who were admitted to our hospital between January 2009 and December 2011. The serotypes and antibiotic resistance of strains of S.pneumoniae were determined using the capsular swelling method and the E-test.

Results

A total of 61 invasive strains were isolated. The serotype distribution of those isolates were 19A (41.0%), 14 (19.7%), 19F (11.5%), 23F (9.8%), 8 (4.9%), 9V (4.9%), 1 (3.3%), and 4, 6B, and 20 (each 1.6%). The percentage of S. pneumoniae strains resistant to erythromycin, clindamycin, and cotrimoxazole were 100%, 86.9%, and 100%, respectively. The percentage of S. pneumoniae strains resistant to penicillin, amoxicillin/clavulanic acid, cefuroxime, ceftriaxone, cefotaxime, cefepime, and meropenem were 42.6%, 18.0%, 82.0%, 18.0%, 13.1%, 13.1%, and 36.1%, respectively. The percentage of multidrug-resistant strains was 95.6%. Strains of all serotypes isolated in this study were highly resistant to erythromycin, cotrimoxazole, and clindamycin. Strains with serotype 19A had the highest rates of resistance.

Conclusions

Serotype 19A strains were most frequently isolated from children with IPD treated in our hospital. The strains causing IPD are highly resistant to antibiotics.     

Changes in antibiotic sensitivity in strains of Staphylococcus aureus, 1952-78.

Two hundred strains of Staphylococcus aureus isolated from outpatients with infections of the skin and subcutaneous tissues were tested for sensitivity to penicillin, erythromycin, tetracycline, sodium fusidate, methicillin, clindamycin, chloramphenicol, and gentamicin. One hundred and sixty-three (81.5%) of the strains were resistant to penicillin and 16 (8%) resistant to tetracycline. Incidence of resistance to other antibiotics was low. No strain was resistant to chloramphenicol, gentamicin, or methicillin. When compared with results of earlier studies, there was an increase in the incidence of resistance to penicillin and tetracycline, but no appreciable increase in resistance to other antibiotics.     

Multiple antibiotic resistance in Rhizobium japonicum.

A total of 48 strains of the soil bacterium Rhizobium japonicum were screened for their response to several widely used antibiotics. Over 60% of the strains were resistant to chloramphenicol, polymyxin B, and erythromycin, and 47% or more of the strains were resistant to neomycin and penicillin G, when tested by disk assay procedures. The most common grouping of resistances in strains was simultaneous resistance to tetracycline, penicillin G, neomycin, chloramphenicol, and streptomycin (25% of all strains tested). The occurrence of multiple drug resistance in a soil bacterium that is not a vertebrate pathogen suggests that chemotherapeutic use of antibiotics is not required for the development of multiple drug resistance.     

Multiple antibiotic resistance in Rhizobium japonicum.

A total of 48 strains of the soil bacterium Rhizobium japonicum were screened for their response to several widely used antibiotics. Over 60% of the strains were resistant to chloramphenicol, polymyxin B, and erythromycin, and 47% or more of the strains were resistant to neomycin and penicillin G, when tested by disk assay procedures. The most common grouping of resistances in strains was simultaneous resistance to tetracycline, penicillin G, neomycin, chloramphenicol, and streptomycin (25% of all strains tested). The occurrence of multiple drug resistance in a soil bacterium that is not a vertebrate pathogen suggests that chemotherapeutic use of antibiotics is not required for the development of multiple drug resistance.     

The genetic diversity and phenotypic characterisation of Streptococcus agalactiae isolates from Rio de Janeiro, Brazil

Streptococcus agalactiae isolates are more common among pregnant women, neonates and nonpregnant adults with underlying diseases compared to other demographic groups. In this study, we evaluate the genetic and phenotypic diversity in S. agalactiae strains from Rio de Janeiro (RJ) that were isolated from asymptomatic carriers. We analysed these S. agalactiae strains using pulsed-field gel electrophoresis (PFGE), serotyping and antimicrobial susceptibility testing, as well as by determining the macrolide resistance phenotype, and detecting the presence of the ermA/B, mefA/E and lnuB genes. The serotypes Ia, II, III and V were the most prevalent serotypes observed. The 60 strains analysed were susceptible to penicillin, vancomycin and levofloxacin. Resistance to clindamycin, chloramphenicol, erythromycin, rifampin and tetracycline was observed. Among the erythromycin and/or clindamycin resistant strains, the ermA, ermB and mefA/E genes were detected and the constitutive macrolides, lincosamides and streptogramin B-type resistance was the most prevalent phenotype observed. The lnuB gene was not detected in any of the strains studied. We found 56 PFGE electrophoretic profiles and only 22 of them were allocated in polymorphism patterns. This work presents data on the genetic diversity and prevalent capsular serotypes among RJ isolates. Approximately 85% of these strains came from pregnant women; therefore, these data may be helpful in developing future prophylaxis and treatment strategies for neonatal syndromes in RJ.     

Transduction transmission of the extrachromosomal markers of antibiotic resistance in staphylococcal populations]

Transduction of extrachromosomal markers of resistance to penicillin and erythromycin in staphylococcal strains isolated from patients was studied. Two transduction methods were compared, i. e. transduction with a phage filtrate of the donor culture resistant to erythromycin and transduction on mixed cultivation of the donor and recipient. A higher transduction rate was observed with the latter method. Mixed cultivation of the donor cultures resistant to penicillin or erythromycin and the recipient strains of the wild type sensitive to these antibiotic resulted in transduction of the respective markers. Transductants which acquired prophage 6 simultaneously with marker Egg became donors of erythromycin resistance.     

Antimicrobial resistance of animal and human strains of Enterobacteriaceae in Greece

Two hundred sixty two strains of Enterobacteriaceae from animal and human sources where intermixing and/or spreading is possible were examined for their resistance to 15 antimicrobials frequently used in animal prophylaxis and metaphylaxis. The antimicrobials with the highest proportion of resistant strains from animal sources were amoxicillin 25 mg, colistin sulphate 25 mg, erythromycin 5 mg, penicillin G 10 mg and spectinomycin 10 mg. The same with isolates from human sources where ampicillin 10 mg, amoxicillin 25 mg, colistin sulphate 25 mg, erythromycin 5 mg, neomycin 10 mg, penicillin G 10 mg and spectinomycin 10 mg. Human isolates were resistant to more antimicrobials than animal isolates. Common a high proportion of isolates from both sources were resistant to some antimicrobials. Systematic and better distributed information is needed to address the epidemiological role of veterinary treatment, prophylaxis and metaphylaxis in antimicrobial resistance in Greece.     

Serotypes and biotypes and antibiotic susceptibility of Haemophilus influenzae encountered in a clinical laboratory in Taiwan.

Forty-four serologically and biochemically typable Haemophilus influenzae isolates from clinical specimens in Taiwan were subjected to analysis in their relationship with source of isolation and age distribution. It was found that all isolates from blood and cerebrospinal fluid were serotype b, biotype I, and all were in children less than 4 years of age. Serotypes b and e, biotypes I and III were encountered to have the highest incidence of infection caused by H. influenzae in this area. All H. influenzae isolates were further tested for susceptibility to several selected antibiotics. All strains of this organism were susceptible to erythromycin and chloramphenicol. All but two strains were susceptible to tetracycline, whereas more strains were resistant to carbenicillin, gentamycin, keflin, and penicillin. Thirty-four percent strains were found to be resistant to ampicillin and all were beta-lactamase producer. No direct correlation between ampicillin resistance and serotypes or biotypes was recognized.     

The drug susceptibility of penicillin-resistant Streptococcus pneumoniae

The aim of our study was to evaluate a frequency of isolation and susceptibility to antibiotics of Streptococcus pneumoniae penicillin resistant among 154 strains S. pneumoniae isolated between 2003 and 2006 in University Hospital of Dr. A. Jurasza in Bydgoszcz. Antimicrobial susceptibility was assessed by disc-diffusion method according to the guidelines of Clinical and laboratory Standards Institute and The national Reference Centre for Antimicrobial Susceptibility. Minimal inhibitory concentrations for penicillin and cefotaxime were assessed by E-test method. Study shows increasing isolation of SPPR strains from 8,2% in 2003 to 32,0% in 2006. Strains were mostly isolated from patients ofNeurosurgery and Neurotraumatology Clinic and Rehabilitation Clinic. SPPR strains were mainly isolated from respiratory tract. Over 68% of SPPR showed intermediate resistance to penicillin and 73,3% of strains were susceptible to cefotaxime. Between 2003 and 2006 increased percentage of resistance strains to erythromycin, tetracycline and sulphometoxasol.     

Relationship between resistance to metallic ions and production of beta-lactamase in strains of Staphylococcus epidermidis.

Thirty five strains of Staphylococcus epidermidis were tested for resistance to penicillin G, erythomycin, metallic ions Zn, As3, As5, Cd, Hg, Pb and activity of beta-lactamase. These studies have shown that the majority of tested staphylococci were resistant to penicillin G, erythromycin, and produced beta-lactamase. No correlation between the activity of beta-lactamase and the resistance to metallic ions has been shown.     

Antibiotic resistance in Streptococcus pneumoniae and Haemophilus influenzae. Report of a study group on bacterial resistance.

Twenty laboratories in England and Scotland took part in 1977 in a survey of antibiotic resistance in Streptococcus pneumoniae and Haemophilus influenzae. In Str pneumoniae 59 (6.8%) of the 866 strains studied were resistant to tetracycline and three to chloramphenicol, and one strain showed a decreased susceptibility to penicillin. The prevalence of resistance to tetracycline was lower than that found in a similar study performed in 1975. Nine hundred and fifty-two strains of H influenzae were examined: 15 (1.6%) were resistant to ampicillin (all were beta-lactamase producers) and 26 (2.7%) to tetracycline. Only two strains were resistant to chloramphenicol and two to trimethoprim. Sixty-three H influenzae strains were capsulated. Thirty-four of these were of Pittman type b, and antibiotic resistance, particularly to ampicillin, was more common in these than in other serotypes or non-typable strains. Some variation was seen in the resistance rate of both H influenzae and Str pneumoniae to tetracycline in strains from different centres, but too few were isolated to assess whether this represented a true geographical difference.     

Dynamics of Streptococcos pneumoniae antibiotic resistance extension in Moscow in 1998-2003]

During the 6-year observation period from 1998 to 2003 in Moscow there was recorded in 2000-2001 a decrease in the emergence of Streptococcos pneumoniae resistance to many antibacterials, while during the following years the respective index increased. The above dynamics in the resistance emergence was likely due to a decrease in the use of antibiotics in 1998-1999. In 2003 the rate of resistance to penicillin was 18.6%, 0.4 and 2.1% of the isolates were resistant to amoxicillin and cefotaxime respectively, the rate of resistance to erythromycin reached 19%, 65.4% of the resistant strains showed M phenotype. High rates of resistance were as well observed with respect to tetracycline (40.1%), co-trimoxazole (29.1%) and chloramphenicol (18.6%). Resistance to levofloxacin and moxifloxacin was detected only in rare strains.     

Serotype distribution of Streptococcus pneumoniae in north-western Greece and implications for a vaccination programme

Serotypes and antibiotic sensitivities were determined for 338 strains of Streptococcus pneumoniae from children of north-western Greece with invasive pneumococcal disease (IPD), acute otitis media (AOM) and nasopharyngeal carriage. The most common serotypes among the isolates from IPD were 14 and 19F, while 3, 19F, 9V and 14 were the major cause of AOM. In these groups, the heptavalent conjugate vaccine for pneumococci (7vPCV) seems to cover 90.5% of the serotypes isolated from children less than 2 years old. Serotypes 23F and 6B were the most prevalent in carrier strains. Overall, 23.7% of the isolates were penicillin nonsusceptible (PNS), 97% were fully susceptible to cefotaxime, 29% were resistant to erythromycin, 11.2% to co-trimoxazole and 1.2% to clindamycin.     

Pneumococci resistant to erythromycin.

Susceptibility to erythromycin was determined for all pneumococci isolated in one laboratory from clinical specimens between 1969 and 1977. All 4724 isolates examined prior to October 1973 were susceptible to erythromycin. From October 1973 to December 1977, 64 (0.71%) of 8995 pneumococcus isolates were resistant to erythromycin. The resistant strains were isolated from 38 patients living in six widely separated communities in Alberta. The erythromycin-resistant strains were of nine capsular types, including six that often cause bacteremic disease and five for which resistance to erythromycin has not been reported hitherto. Certain strains of type 33 and of type 15 were highly resistant, the minimum inhibitory concentration (MIC) of erythromycin being 2000 microgram/mL; these strains were also highly resistant to lincomycin and clindamycin. Resistance in strains of other types was much lower, the MIC of erythromycin being 0.6 to 20 microgram/mL, and all but one of these strains were susceptible to lincomycin and clindamycin. All the erythromycin-resistant pneumococci were suspectible to penicillin.     

Antimicrobial resistance among Brazilian Corynebacterium diphtheriae strains

The increasing problems with multidrug resistance in relation to Corynebacterium, including C. diphtheriae, are examples of challenges confronting many countries. For this reason, Brazilian C. diphtheriae strains were evaluated by the E-Test for their susceptibility to nine antibacterial drugs used in therapy. Resistance (MIC < 0.002; 0.38 microg/ml) to penicillin G was found in 14.8% of the strains tested. Although erythromycin (MIC90 0.75 microg/ml) and azithromycin (MIC90 0.064 microg/ml) were active against C. diphtheriae in this study, 4.2% of the strains showed decreased susceptibility (MIC 1.0 microg/ml) to erythromycin. Multiple resistance profiles were determined by the disk diffusion method using 31 antibiotics. Most C. diphtheriae strains (95.74%) showed resistance to mupirocin, aztreonam, ceftazidime, and/or oxacillin, ampicillin, penicillin, tetracycline, clindamycin, lincomycin, and erythromycin. This study presents the antimicrobial susceptibility profiles of Brazilian C. diphtheriae isolates. The data are of value to practitioners, and suggest that some concern exists regarding the use of penicillin.     

Effect of an interferon preparation on increasing bacterial sensitivity to antibiotics

Under the effect of human leukocytic alpha-interferon-II for injections there was observed an increase in sensitivity of bacteria to benzylpenicillin, ristomycin, novobiocin, streptomycin, kanamycin, monomycin and erythromycin. A higher antibacterial effect of the penicillin and erythromycin was recorded only with respect to initially resistant strains of staphylococci. For the antibiotic resistant strains of staphylococci the MICs of the penicillin and erythromycin decreased on the average 17.8 and 208 times (p less than 0.001) respectively. The interferon had no effect on sensitivity of bacteria to chloramphenicol.     

Drug Resistance of Enteric Bacteria XIII. Distribution of R Factors in Escherichia coli Strains Isolated from Livestock

Escherichia coli strains isolated from 151 swine and 108 fowl, which were kept at the Animal Health Center, Maebashi, Japan, were surveyed for drug resistance and distribution of R factors. All of the swine and 38% of the fowl excreted E. coli strains resistant to tetracycline, chloramphenicol, streptomycin, and sulfanilamide, or certain combinations thereof. Among 278 resistant cultures isolated from swine, 13% were found to be resistant to one antibiotic, whereas 87% were resistant to more than one antibiotic. Among these resistant strains, 40% carried R factors which were transferable by the usual conjugal process. The resistance patterns of these R factors included 36% which were singly resistant and 64% which were multiply resistant. Among 54 resistant cultures isolated from fowl, 24% were singly resistant and 76% were multiply resistant. Of the resistant strains from fowl, 22% carried R factors. The resistance patterns of R factors included 50% of the singly resistant type and 50% which were multiply resistant. In spite of feeding with dairy products containing only tetracycline, a high incidence of multiple resistance was observed in the E. coli strains and the R factors isolated from these animals.     

Prevalence of antibiotic resistance and serotypes in pneumococci in England and Wales: results of observational surveys in 1990 and 1995.

OBJECTIVE--To assess the prevalence of antibiotic resistance and serotype distribution among pneumococci in England and Wales in 1990 and 1995. DESIGN--Observational surveys in March 1990 and March 1995. During two weeks in each survey period all pneumococci isolated in public health laboratories in England and Wales were collected and assessed for sensitivity to antibiotics and the distribution of serogroups or serotypes. SETTING--The network of public health laboratories throughout England and Wales. SUBJECTS--1127 individual patient isolates of Streptococcus pneumoniae obtained during the two surveys. MAIN OUTCOME MEASURES--Sensitivity or resistance to a range of antibiotics; serogroup or serotype. RESULTS--The prevalence of intermediate or full resistance to penicillin increased from 1.5% in 1990 to 3.9% in 1995 and resistance to erythromycin increased from 2.8% to 8.6%. About 92% of isolates belonged to serogroups or serotypes included in the currently available pneumococcal vaccine. CONCLUSION--Resistance to penicillin and erythromycin has increased among pneumococci in England and Wales. Continued surveillance to assess further increases in the prevalence of pneumococcal resistance to antibiotics is essential.     

Sensitivity to antibacterial preparations of the pathogenic staphylococci isolated from carriers]

After discontinuation of the use of antibiotics for sanation of the carriers of pathogenic staphylococci among the staff of a maternity unit, the number of the strains resistant to penicillin, streptomycin, chlortetracycline, tetracycline, levomycetin, erythromycin, monomycin and neomycin decreased 1.3, 2.9, 10,4.3,5.5,1.5,3.9 and 2.4 times respectively. The differences were statistically reliable. The causes of the antibiotic resistance decrease require further investigation.     

Streptococcus pneumoniae serotypes in children with acute pneumonia and pleurisy

The study of pneumococci of different serotypes, isolated from patients with acute pneumonia and pleuritis and from healthy children was carried out. Among the pneumococcal serotypes causing pneumonia and pleuritis in children serotypes 1, 6, 19, 14 and 3 were most widely spread and constituted 62.3% of all isolated pneumococci. In young children cases of acute pneumonia and pleuritis were more often induced by serotypes 6 and 14 and in older children, by serotypes 1 and 3. In patients with uncomplicated pneumonia and pleuritis differences in the detected serotypes of pneumococci were observed, and the disease course differed in severity. Serotypes 14, 3 and 3 induced destructive processes in the lungs more often than other serotypes. Monitoring of the sensitivity of pneumococci to antibiotics showed that most of the strains retained high sensitivity to penicillin and ampicillin. In most cases the detected resistant pneumococcal strains belonged to serogroup 19.