Antibiotic-resistant pneumococci carried by young children do not appear to disseminate to adult members of a closed community.

Although antibiotic-resistant pneumococci have been frequently detected among day care center (DCC) attendees, the transmission of these organisms to other members of the community has not been adequately studied. Nasopharyngeal cultures were obtained from 152 children and 244 adult members of a closed community (a kibbutz) in Israel. Serotyping, antibiogram, and pulsed-field gel electrophoresis were performed to determine the relatedness of isolated pneumococci.

A decade (1989-1998) of pediatric invasive pneumococcal disease in 2 populations residing in 1 geographic location: implications for vaccine choice.

During 1 decade (1989-1998), data on invasive pneumococcal disease were collected prospectively to assess the burden of disease among Jewish and Bedouin children in southern Israel and the potential reduction in illness that can be achieved by using conjugate vaccines. Data on 513 children <15 years old with bacteriologically proven invasive pneumococcal disease were obtained. Among Jewish and Bedouin children <5 years old, incidence rates were 45 and 139 cases per 100,000 child-years of observation, respectively.

Early responses to nonconjugated polyribosylribitol phosphate challenge as evidence of immune memory after combined diphtheria-tetanus-pertussis-polio-Haemophilus influenzae type b primary vaccination.

Objectives: A high risk of invasive Haemophilus influenzae type b (Hib) disease exists in the first few years of life. A reduction in anti-polyribosylribitol phosphate (PRP) antibody concentrations follows the administration of certain diphtheria-tetanus-acellular pertussis (DTPa)-based Hib conjugate combined vaccines. However, these combined vaccines prime the immune memory, which is an important factor in protection.

Persistence of two invasive Streptococcus pneumoniae clones of serotypes 1 and 5 in comparison to that of multiple clones of serotypes 6B and 23F among children in southern Israel.

We conducted a study to examine the clonal distribution of invasive serotype 1 and 5 isolates as representatives of serotypes that are rarely carried by healthy individuals compared to that of invasive serotype 6B and 23F isolates as representatives of serotypes often carried by young children for prolonged periods. All invasive serotype 1, 5, 6B, and 23F isolates recovered from blood cultures during January 1995 to May 1999 were analyzed; these included 66 serotype 1, 30 serotype 5, 11 serotype 6B, and 15 serotype 23F isolates. One hundred thirty-three nasopharyngeal (NP) isolates of the indicated four serotypes from healthy children were also studied.

Tolerability and immunogenicity of an eleven-valent pneumococcal conjugate vaccine in healthy toddlers.

Background: A need to increase the serotype coverage of pneumococcal conjugate vaccines exists. The use of a single carrier protein may cause overload of the carrier and decrease the immune response by not providing sufficient carrier-specific T helper cell support. A vaccine composed of a mixture of tetanus- and diphtheria-conjugated polysaccharides (PS) is a potential solution to this issue.

Bacteriologic and clinical efficacy of trimethoprim-sulfamethoxazole for treatment of acute otitis media.

Background: Trimethoprim-sulfamethoxazole (T/S) has often been used as first and second line of treatment for acute otitis media (AOM). Because of the increasing resistance of Streptococcus pneumoniae and Haemophilus influenzae to T/S, we undertook the present study to investigate the bacteriologic and clinical efficacy of this drug in AOM.

Methods: Fifty-four culture-positive evaluable patients ages 3 to 32 months with AOM were treated with T/S 4/20 mg/kg in two divided daily doses for 10 days.

[Characteristics of nasopharyngeal carriage of Streptococcus pneumoniae in children during acute respiratory disease].

Streptococcus pneumoniae is an important cause of pediatric morbidity and its main reservoir is the nasopharynx, from which it can disseminate and cause invasive disease. From November 1997 through March 1998, nasopharyngeal carriage of S. pneumoniae was evaluated in 250 children under the age of 36 months: 123 Jews and 127 Bedouins with acute respiratory disease and in 980 healthy control children (852 Jews and 128 Bedouins).

Antibiotic treatment in acute Otitis Media promotes superinfection with resistant Streptococcus pneumoniae carried before initiation of treatment.

Antibiotic-resistant pneumococci are difficult to eradicate from middle ear fluid (MEF) and the nasopharynx (NP). Bacteriologic eradication from the NP and MEF during acute otitis media (AOM) by 3 common antibiotic drugs was prospectively evaluated. In 19 (16%) of 119 MEF culture-positive patients, an organism susceptible to the treatment drug (Haemophilus influenzae, Streptococcus pneumoniae, or both) was isolated from the initial MEF, whereas resistant S.

Evaluation of a medium (STGG) for transport and optimal recovery of Streptococcus pneumoniae from nasopharyngeal secretions collected during field studies.

Field studies of Streptococcus pneumoniae (pneumococci) nasopharyngeal (NP) colonization are hampered by the need to directly plate specimens in order to ensure isolate viability. A medium containing skim milk, tryptone, glucose, and glycerin (STGG) has been used to transport and store NP material, but its ability to preserve pneumococci has not been evaluated. Our objective was to qualitatively and semiquantitatively evaluate the ability of STGG to preserve pneumococci in NP secretions.

Development of a chemiluminescent optical fiber immunosensor to detect Streptococcus pneumoniae antipolysaccharide antibodies.

A chemiluminescent-based optical fiber immunosensor was developed for the detection of antipneumococcal antibodies. This was accomplished by developing a different chemical procedure utilizing 3-aminopropyl trimethoxysilane and cyanuric chloride to conjugate pneumococcal cell wall polysaccharides to the optical fiber tips, and by improving the sensitivity of the photodetection system. The lowest titer of antipneumococcal antibodies detected by the optical fiber was at a 1:819,200 dilution.

Treatment of acute otitis media - challenges in the era of antibiotic resistance.

The last decade is characterized by the increase in antibiotic resistance among respiratory bacterial pathogens in the presence of only modest progress in the development of new antibacterial agents to overcome this resistance. A series of recent studies show clearly that the increased resistance among the main AOM pathogens (namely Streptococcus pneumoniae and Haemophilus influenzae) is associated with a dramatic decrease in bacteriologic response to antibiotic treatment, which in turn has an impact on clinical response. Thus, the individual patient is affected by the increasing antibiotic resistance.

Identification and characterization of a novel family of pneumococcal proteins that are protective against sepsis.

Four pneumococcal genes (phtA, phtB, phtD, and phtE) encoding a novel family of homologous proteins (32 to 87% identity) were identified from the Streptococcus pneumoniae genomic sequence. These open reading frames were selected as potential vaccine candidates based upon their possession of hydrophobic leader sequences which presumably target these proteins to the bacterial cell surface. Analysis of the deduced amino acid sequences of these gene products revealed the presence of a histidine triad motif (HxxHxH), termed Pht (pneumococcal histidine triad) that is conserved and repeated several times in each of the four proteins.

Cryptosporidium infection in Bedouin infants assessed by prospective evaluation of anticryptosporidial antibodies and stool examination.

An enzyme-linked immunosorbent assay system using oocyst lysate as antigen was used to detect serum- specific antibody responses to Cryptosporidium parvum between 1989 and 1994 in consecutive sera obtained at birth, and at the age of 6, 12, and 23 months, from 52 infants living in a Bedouin town located in the south of Israel. The serologic tests revealed high levels of immunoglobulin G anti-Cryptosporidium at birth that dropped significantly by the age of 6 months and then rose continuously to a geometric mean titer of 481 at age 23 months. The serum immunoglobulin M Cryptosporidium antibodies rose continuously from nearly undetectable levels at birth to a geometric mean titer of 471 (157-fold increase) at age 23 months.

Evidence to support the rationale that bacterial eradication in respiratory tract infection is an important aim of antimicrobial therapy.

Clinical outcome is dependent upon antibiotic-mediated bacterial eradication in a number of infections. However, in respiratory tract infections, the need for bacterial eradication has been controversial. Clinical data are now available that support the need for active bacterial eradication in otitis media.

Oral ciprofloxacin vs. intramuscular ceftriaxone as empiric treatment of acute invasive diarrhea in children.

Background: Acute invasive diarrhea is a potentially serious condition in children. Because of the increasing resistance of enteric pathogens to commonly used oral antibiotics, intramuscular ceftriaxone has become the routine drug in the treatment of acute invasive diarrhea requiring an emergency visit in southern Israel. The inconvenience of this parenteral regimen created an increased need for oral pediatric formulations for the treatment of invasive diarrhea.

Immunization against hepatitis A in the first year of life: priming despite the presence of maternal antibody.

Background: Maternal antibodies interfere with hepatitis A vaccination in young infants. We examined the response to a high dose hepatitis A vaccine administered concomitantly with a combination of diphtheria-tetanus toxoids-acellular pertussis-inactivated poliovirus vaccine/Haemophilus influenzae type b vaccine to initially seropositive vs. initially seronegative infants.

Bacteriologic and clinical efficacy of one day vs. three day intramuscular ceftriaxone for treatment of nonresponsive acute otitis media in children.

Background: One dose of intramuscular ceftriaxone has been recently licensed in the United States for the treatment of acute otitis media. However, data regarding the bacteriologic and clinical efficacy of this regimen in the treatment of nonresponsive acute otitis media are incomplete.

Objectives: To determine the bacteriologic and clinical efficacy of a 1-day 50-mg/kg vs.

Mediterranean clone of penicillin-susceptible, multidrug-resistant serotype 6B Streptococcus pneumoniae in Greece, Italy and Israel.

In 1996, 19 isolates of serotype 6B Streptococcus pneumoniae with a unique resistance pattern were found in carriers attending daycare centres in Patras, Southwestern Greece. These isolates were penicillin susceptible but resistant to chloramphenicol, tetracycline, erythromycin, clindamycin and trimethoprim-sulphamethoxazole. Subsequently, isolates with the same characteristics were found in 23 additional carriers in central and southern Greece in 1997-98 as well as in 19 carriers in central Italy in 1997, and in seven carriers in southern Israel in 1998.

Middle ear effusion IL-6 concentration in bacterial and non-bacterial acute otitis media.

Background: The pathogenesis of acute otitis media is complex and multifactorial. It is characterized by inflammation of the middle ear with an infiltration of leukocytes, macrophages and mast cells. The resulting effusion contains a large amount of inflammatory mediators, among which are cytokines.

Hospitalization for primary varicella-zoster virus infection and its complications in patients from Southern Israel.

Background: We conducted this study to determine the impact of chickenpox on two different ethnic populations in southern Israel: Jews and Bedouins.

Methods: Hospital records of 113 patients discharged from the Soroka Medical Center with the diagnosis of varicella during a 4.5-year period were reviewed.

Antibiotic treatment for acute otitis media.

The major problems encountered in the antibiotic therapy of acute otitis media (AOM) are the tremendous increase in the resistance to antibiotics of its main pathogens and the lack of tight criteria (taking into consideration, as a major determinant, the eradication of the pathogens from the middle ear fluid) in the selection of the appropriate antibiotic drugs for the treatment of this disease. Future drugs for the treatment of AOM will have to be approved only after their in vivo microbiological efficacy for each major pathogen is documented. This documentation will be provided by more antibiotic studies with bacteriological outcome using the double-tympanocentesis method and stratifying the AOM patients by age and initial clinical severity.

Initial steps in Streptococcus pneumoniae interaction with and pathogenicity to the host.

Streptococcus pneumoniae (Pnc) is one of the leading pathogens in the world. Attachment to respiratory mucosal and lung surfaces is presumed to be involved in carriage, in disease and in the interaction with macrophages initiating innate immune responses. We hypothesized that bacterial adhesins mediate Pnc adhesion and host cell invasiveness.

[Development of molecular tests for rapid detection of enteropathogens].

Amplification of specific DNA sequences by polymerase chain reaction (PCR), enables rapid, sensitive and direct, specific identification of pathogens at very low concentrations in clinical samples. Studies in recent years have reported identification of several enteropathogens directly from stool samples by PCR. The amplification process includes the use of primers complementary to the DNA sequences specific to the pathogen, thus relying on the pathogen's genotype, rather than its phenotype on which identification by the methods of classical microbiology were based.