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Biomedical subjects

A E Gober

Publications and source records attributed to A E Gober.

At least 19 recordsLinked to original sources
PubMed2000

In vitro bacterial interference in the nasopharynx of otitis media-prone and non-otitis media-prone children.

OBJECTIVE: To compare the frequency of recovery of potential pathogens and aerobic- and anaerobic-interfering bacteria in the nasopharynx of otitis media-prone (OMP) with that in non-OMP (N-OMP) children. PATIENTS AND METHODS: Nasopharyngeal cultures were obtained from 20 OMP and 20 N-OMP children. Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these organisms were identified. RESULTS: Eighteen potential pathogens were isolated from 12 of the 20 OMP children, and 9 were recovered from 5 of the 20 N-OMP children (P<.05). Fifty-eight aerobic and anaerobic isolates with interfering capability against 4 potential pathogens were recovered from 5 of the OMP group, and 139 from 17 of the N-OMP group (P<.05). These interfering organisms included alphahemolytic streptococci, nonhemolytic streptococci, Prevotella species, and Peptostreptococcus species. CONCLUSION: The nasopharyngeal flora of N-OMP children contains more aerobic and anaerobic organisms with interfering capability and less potential pathogens than that of OMP children.

Child, Preschool↗
PubMed2000

Dynamics of nasopharyngitis in children.

PURPOSE: Our goal was to characterize the dynamics and bacterial interaction of the aerobic and anaerobic flora of nasal discharge of children at different stages of uncomplicated nasopharyngitis. METHODS AND PATIENTS: Serial semiquantitative nasopharyngeal (NP) and quantitative nasal discharge (ND) cultures were taken every 3 to 5 days from 20 children in whom purulent discharge eventually developed (group 1), and a single culture was obtained from a group of 20 who had only clear discharge (group 2). RESULTS: Aerobic and anaerobic bacteria were isolated from all NP cultures. Bacterial growth was present in 8 (40%) NDs of group 2. Only 7 (35%) of the clear NDs of group 1 showed bacterial growth; the number increased to 14 (70%) at the mucoid stage and 20 (100%) at the purulent stage. It declined to 6 (30%) at the final clear stage. The number of species and total number of organisms increased in the NDs of group 1. Group 1 patients had higher recovery rates of Streptococcus pneumoniae and Haemophilus influenzae in their NP cultures than group 2 patients (P < 0.05). During the purulent stage, Peptostreptococcus species were isolated in 15 (75%), Fusobacterium species in 10 (50%), Prevotella species in 9 (45%), H influenzae in 8 (40%), S pneumoniae in 6 (30%), and beta-hemolytic streptococci in 5 (25%) of group 1 NDs. This was higher than their recovery in the clear stages of both groups and the mucoid stage of group 1. A total of 8 organisms capable of interfering with the growth of potential pathogens were isolated from the NPs of group 1, as compared with 35 from group 2 (P < 0.001). CONCLUSIONS: The development of purulent nasopharyngitis is associated with the pre-existing presence of potential pathogens and the absence of interfering organisms.

Antibiosis↗
PubMed1999

Interference by aerobic and anaerobic bacteria in children with recurrent group A beta-hemolytic streptococcal tonsillitis.

OBJECTIVE: To compare the frequency of recovery of aerobic and anaerobic bacteria with interfering capability of group A beta-hemolytic streptococci (GABHS) in the tonsils of children with and without a history of recurrent GABHS pharyngotonsillitis. PATIENTS AND METHODS: Tonsillar cultures were taken from a group of 20 children with and 20 without history of recurrent GABHS pharyngotonsillitis. RESULTS: Eleven aerobic and anaerobic isolates with interfering capability with GABHS were recovered from 6 (30%) of the 20 children with recurrent GABHS, and 40 such organisms were isolated from 17 (85%) of the 20 without recurrences (P<.01). The interfering organisms included aerobic (alpha-hemolytic and nonhemolytic streptococci) and anaerobic organisms (Prevotella and Peptostreptococcus species). CONCLUSIONS: The tonsils of children with a history of recurrent GABHS infection contain fewer aerobic and anaerobic bacteria with interfering capability of GABHS than those without the history of recurrent GABHS infection. The presence of these interfering bacteria may play a role in preventing GABHS infection.

Adolescent↗
PubMed1999

Bacterial interference in the nasopharynx and nasal cavity of sinusitis prone and non-sinusitis prone children.

The aim of this study was to compare the frequency of recovery of potential pathogens and aerobic and anaerobic interfering bacteria in the nasopharynx and nasal cavity of sinusitis prone (SP) children, with their recovery in non-sinusitis prone (N-SP) children. Nasopharyngeal and nasal cultures were taken from 20 SP and 20 N-SP children. Potential pathogens and aerobic and anaerobic bacteria with interfering capabilities against these micro-organisms were identified. Twenty-one potential pathogens (1.05 patient) were isolated from nasopharyngeal cultures from 14 of the 20 SP children, and 10 (0.5 patient) were recovered from 6 of the 20 NSP (p < 0.05). Bacterial interference between two aerobic (alpha and non-haemolytic streptococci) and two anaerobic species (Prevotella and Peptostreptococcus species) and four potential pathogens was observed. Bacterial interference was noted in 64 instances against 4 potential pathogens by 24 normal flora isolates that were recovered from 7 of the SP group and in 144 instances by 47 isolates from 18 of the NSP group (p < 0.05). Nineteen potential pathogens (0.95/patient) were isolated from nasal cultures of 13 of the 20 SP children and 8 (0.4/patient) were recovered from 5 of the 20 NSP (p < 0.05). Bacterial interference by similar micro-organisms was noted in 21 instances by 9 normal flora isolates that were recovered from 5 of the SP group, and in 63 instances by 26 isolates from 15 of the NSP group (p < 0.05). Our findings illustrate for the first time that the nasopharyngeal and nasal flora of NSP children contains more aerobic and anaerobic micro-organisms with interfering capability and less potential pathogens than that of SP children.

Adolescent↗
PubMed1999

Resistance to antimicrobials used for therapy of otitis media and sinusitis: effect of previous antimicrobial therapy and smoking.

We undertook to identify the antimicrobial susceptibility of the pathogens isolated from patients with otitis media or maxillary sinusitis who failed to respond to antimicrobial therapy, and correlate it with previous antimicrobial therapy and smoking. We analyzed isolates recovered from 2 consecutive cultures obtained from middle ear aspirate obtained through an open perforation in 22 children with otitis, and maxillary sinus aspirate collected by endoscopy from 20 patients. Forty-seven isolates were repeatedly recovered from 42 culture-positive individuals. The organisms isolated were Streptococcus pneumoniae (15 isolates), Haemophilus influenzae (14), Staphylococcus aureus (7), Moraxella catarrhalis (6), and Streptococcus pyogenes (5). Resistance of at least 2 tube dilutions to the antimicrobial agents used was found in 23 of the 47 (49%) isolates that were found in 20 (48%) of the patients. These included 10 of 15 (67%) isolates of S pneumoniae, 4 of 14 (29%) H influenzae (all were beta-lactamase producers), 4 of 7 (57%) S aureus (all beta-lactamase producers), 5 of 6 (83%) M catarrhalis (all beta-lactamase producers), and none of 5 S pyogenes. In the 21 patients who failed to respond to amoxicillin, H influenzae and S pneumoniae predominated. Streptococcus pneumoniae was recovered from 4 of the 11 (36%) after trimethoprim-sulfamethoxazole, 4 of 21 (19%) after amoxicillin, 2 of 3 (67%) after azithromycin dihydrate, and 1 of 4 (25%) after cefixime. A statistically significant higher recovery of resistant organisms was noted in those treated 2 to 6 months previously, and in those with sinusitis who smoked. The data illustrate the relationship between resistance to antimicrobials and failure of patients with otitis media and sinusitis to improve.

Adolescent↗
PubMed1998

Microbiologic characteristics of persistent otitis media.

OBJECTIVE: To identify the pathogens isolated from children with acute otitis media who did not respond to antimicrobial drug therapy. METHODS: Retrospective analysis of cultures obtained by tympanocentesis from 46 children. RESULTS: Organisms were recovered from 34 children (74%), and 43 isolates were recovered from these individuals. The organisms were Streptococcus pneumoniae (16 isolates), Haemophilus influenzae non-type b (12 isolates), Moraxella catarrhalis (5 isolates), Streptococcus pyogenes (5 isolates), Staphylococcus aureus (3 isolates), and Peptostreptococcus species (2 isolates). Resistance to the antimicrobial agent used was found in 27 (63%) of 43 isolates found in 22 patients (48%). Of patients who did not respond to amoxicillin therapy, H influenzae predominated. Streptococcus pneumoniae was recovered from 5 (56%) of 9 of those who did not respond to trimethoprim and sulfamethoxazole therapy, 4 (44%) of 9 patients after azithromycin therapy, 3 (25%) of 12 patients after amoxicillin therapy, and 2 (40%) of 5 patients after cefixime therapy. Streptococcus pyogenes was recovered from 2 (40%) of 5 patients after trimethoprim and sulfamethoxazole therapy and from 2 (40%) of 5 patients after cefixime therapy. CONCLUSIONS: The data illustrate the relation between resistance to antimicrobial drug therapy and failure of patients with otitis media to improve. They also highlight the importance of diagnostic tympanocentesis in establishing the presence of resistant microorganisms.

Acute Disease↗
PubMed1998

Persistence of group A beta-hemolytic streptococci in toothbrushes and removable orthodontic appliances following treatment of pharyngotonsillitis.

OBJECTIVE: To investigate the persistence of group A beta-hemolytic streptococci (GABHS) in toothbrushes and removable orthodontic appliances (ROAs) in children who suffer from acute GABHS pharyngotonsillitis and the association with penicillin treatment failure. SETTING: Private practice setting. PATIENTS AND METHODS: Pharyngotonsillar and toothbrush cultures were obtained from 104 children with acute GABHS pharyngotonsillitis before and after 10 days of penicillin V potassium therapy. Cultures of ROAs were also obtained from 21 children. The persistence of GABHS in 10 daily rinsed and 10 nonrinsed toothbrushes was studied in vitro. RESULTS: Group A beta-hemolytic streptococci were isolated from 11 (11%) of the toothbrushes and 18 (17%) of the patients after the completion of penicillin therapy. Toothbrushes of 5 (28%) of the 18 children who harbored GABHS were colonized with the organism. Group A beta-hemolytic streptococci were also isolated from 4 (19%) of 21 ROAs after therapy. In vitro studies illustrated the persistence of GABHS in nonrinsed toothbrushes for up to 15 days. In contrast, the organism was not isolated from rinsed toothbrushes beyond day 3. CONCLUSION: Toothbrushes and ROAs that harbor GABHS may contribute to the persistence of GABHS in the oropharynx and may account for the failure of penicillin therapy in some cases of pharyngotonsillitis.

Child↗
PubMed1998

Bacterial interference in the nasopharynx following antimicrobial therapy of acute otitis media.

The effect on the nasopharyngeal bacterial flora of therapy for 10 days with co-amoxiclav or cefprozil was studied in 50 children with acute otitis media. Before therapy, potential pathogens (Streptococcus pneumoniae, Haemophilus influenzae and Moraxella catarrhalis) were isolated in 14 (56%) of those treated with co-amoxiclav and 15 (60%) of those treated with cefprozil. Following therapy, the reduction in the number of these pathogens was the same in the two groups. However, differences between the groups were noted in the recovery of organisms with interfering capability, namely alpha-haemolytic streptococci, Peptostreptococcus anaerobius and Prevotella melaninogenica. Fifty interfering organisms were recovered from each group before therapy. After therapy with co-amoxiclav or cefprozil their number declined to 11 and 42, respectively (P< 0.001).

Amoxicillin-Potassium Clavulanate Combination↗
PubMed1997

Bacterial colonization of pacifiers of infants with acute otitis media.

The presence of aerobic and facultative anaerobic bacteria on the surface of pacifiers used by children with acute otitis media was investigated. The surface of 40 recently used pacifiers was swabbed after they were allowed to dry for five to six minutes. The swabs were processed quantitatively for the presence of aerobic bacteria. The antibacterial activity of the pacifier material was tested in vitro. Microorganisms were isolated from 21 (52.5 per cent) pacifiers. The number of colonies per pacifier varied between one and 35 (average six). The isolates included eight alpha-haemolytic streptococci, six Staphylococcus epidermis, five Candida albicans, five alpha-haemolytic streptococci, three Neisseria spp. and two Staphylococcus aureus. The pacifier material was shown to be inhibitory against S. aureus. This study illustrated that pacifiers do not contain high numbers of organisms and therefore are not likely to serve as a source of persistence of transfer of organisms.

Acute Disease↗
PubMed1996

Prophylaxis with amoxicillin or sulfisoxazole for otitis media: effect on the recovery of penicillin-resistant bacteria from children.

The rate of recovery of oropharyngeal penicillin-resistant Streptococcus pneumoniae and aerobic and anaerobic beta-lactamase-producing bacteria (BLPB) from children who received a 4- to 6-month course of prophylaxis with amoxicillin or sulfisoxazole for otitis media was investigated monthly over 9 months. The BLPB recovered were Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, pigmented Prevotella species, and Fusobacterium species. The recovery rate for all penicillin-resistant S. pneumoniae isolates and BLPB increased only after administration of amoxicillin. Before amoxicillin was administered, six BLPB isolates were recovered from four of the children who were to be given this drug (20%). The number of BLPB recovered increased gradually until all of these patients were found to be colonized with BLPB; five (25%) of these patients were found to be colonized with penicillin-resistant S. pneumoniae after 5 months of prophylaxis. Three to five months after amoxicillin prophylaxis was discontinued, the number of BLPB recovered gradually declined; only three children (15%) remained colonized with BLPB, and none remained colonized with penicillin-resistant S. pneumoniae. These data illustrate that amoxicillin prophylaxis induces an increase in the number of penicillin-resistant bacteria in the oropharynx.

Amoxicillin↗
PubMed1996

In-vitro effects of penicillin and clindamycin on the expression of Streptococcus pneumoniae capsule.

The effects of subinhibitory concentrations of penicillin or clindamycin were evaluated in 20 isolates of Streptococcus pneumoniae that were fully susceptible to penicillin and in 20 isolates that were of intermediate resistance. All isolates were capsulate and susceptible to clindamycin. After incubation in one-half of the MIC of clindamycin, 17.5% of isolates retained a capsule, compared to 87.5% after incubation with one-half of the MIC of penicillin. Clindamycin appears to be superior to penicillin in reducing the expression of the capsule by S. pneumoniae.

Anti-Bacterial Agents↗
PubMed1995

Role of bacterial interference and beta-lactamase-producing bacteria in the failure of penicillin to eradicate group A streptococcal pharyngotonsillitis.

OBJECTIVE: To determine the association among bacterial interference and beta-lactamase production and penicillin failure in treating streptococcal pharyngotonsillitis. DESIGN: Fifty-two children who had acute pharyngotonsillitis caused by group A beta-hemolytic streptococci (GABHS) were treated for 10 days with penicillin. Surface tonsillar cultures were obtained before therapy and at 10, 21, and 42 days after termination of therapy. The cultures obtained before and 10 days after completion of treatment were processed for aerobic and anaerobic organisms; the other cultures were processed for GABHS only. RESULTS: Based on eradication of GABHS, 38 patients were in the classification bacteriologic "cure"; 14 were in the classification bacteriologic "failure" after therapy. In the cured group, before therapy alpha-hemolytic streptococci inhibiting their own GABHS were recovered in the cultures of 14 children (37%), and beta-lactamase-producing organisms (BLPB) were detected in the cultures of two children (5%). After therapy, inhibiting alpha-hemolytic streptococci were recovered in 31 cultures (82%), and BLPB were detected in five cultures (13%). In contrast, in the failure group, before therapy alpha-hemolytic streptococci were isolated in one culture (7%) and BLPB were recovered from nine cultures (64%). After therapy, alpha-hemolytic streptococci were recovered in four cultures (29%), and BLPB was recovered in 13 cultures (93%). CONCLUSIONS: These data show that the absence of interfering alpha-hemolytic streptococci and the presence of BLPB is associated with penicillin failure in the treatment of GABHS pharyngotonsillitis.

Adolescent↗
PubMed1995

In vitro and in vivo effects of penicillin and clindamycin on expression of group A beta-hemolytic streptococcal capsule.

Encapsulation of group A beta-hemolytic streptococci (GABHS) is an important virulence factor. The changes that occur in the frequency of encapsulation of GABHS during pharyngotonsillitis, in 20 patients treated with penicillin and 20 treated with clindamycin, were investigated. The effects of subinhibitory concentrations of these agents were also evaluated in vitro. At day 4, 8 of 10 (80%) GABHS isolates recovered from children treated with penicillin were encapsulated, compared with 1 of 5 (20%) of those from children treated with clindamycin (P < 0.05). Two days following 10 days of therapy, GABHS was eliminated from 13 of the 20 (65%) children treated with penicillin and from all treated with clindamycin (P < 0.05). At that time, six of the seven GABHS isolates recovered in patients treated with penicillin were encapsulated. GABHS were not detected after 4 days of therapy in those treated with clindamycin. Incubation of GABHS isolates with one-half of the MIC of clindamycin reduced the frequency of encapsulation, compared with that after incubation with one-half of the MIC of penicillin (12.5 versus 67.5%). These data illustrate the superiority of clindamycin over penicillin in reducing the expression of a capsule by GABHS.

Bacterial Capsules↗
PubMed1984

Rapid method for detecting beta-lactamase producing bacteria in clinical specimens.

The use of liquid media to detect the production of beta-lactamase by beta-lactamase producing organisms has been compared with the conventional method of inoculation on to agar media. Pharyngeal cultures were obtained from 162 children treated with penicillin for acute tonsillitis. beta-lactamase producing organisms were detected within 72 h in 80 (49%) of the specimens inoculated on to agar media, while beta-lactamase production was found in 76 (47%) of the specimens after their incubation in liquid media for 24 h. Twenty one of the cultures were positive only after anaerobic incubation while in liquid media while nine were positive only after aerobic incubation. Incubation in liquid media enabled detection of beta-lactamase activity in 53 of the 76 (70%) specimens within 12 h.

Aerobiosis↗
PubMed1984

Emergence of beta-lactamase-producing aerobic and anaerobic bacteria in the oropharynx of children following penicillin chemotherapy.

The acquisition of beta-lactamase-producing aerobic and anaerobic bacteria was investigated in 21 children treated with penicillin for otitis media or pharyngitis and in 18 untreated control children. Beta-lactamase-producers were isolated in three children before and in ten children after treatment (p = 0.04). Although the variety of bacterial species isolated did not change following treatment, beta-lactamase-producing Bacteroides melaninogenicus, B. oralis, and Branhamella catarrhalis were encountered only after therapy, while some beta-lactamase-producing Staphylococcus aureus and Hemophilus influenzae were found before treatment. The incidence of beta-lactamase-producers did not increase in the control children. Spread of beta-lactamase-producers to household contacts by 12 treated and 13 normal control children also was studied. Ten of the treated children and 15 of 33 of the household contacts harbored beta-lactamase-producers, while none were found in normal control children and only two were found in 27 of their household contacts (comparison of the two household contacts, p less than 0.01).

Acute Disease↗
PubMed1983

Bacteroides melaninogenicus. Its recovery from tonsils of children with acute tonsillitis.

The presence of encapsulated and abscess-forming organisms belonging to the Bacteroides melaninogenicus group was investigated in 25 children with acute tonsillitis, and in 23 children without tonsillar inflammation (control). Encapsulated organisms of the B melaninogenicus group were found in 23 of 25 children with acute tonsillitis as compared with five of 23 controls. Subcutaneous inoculation into mice of the Bacteroides strains isolated from patients with tonsillitis produced abscesses in 17 of 25 instances, as compared with nine of the 23 of the controls. Group A streptococci were recovered from the tonsils of five children with tonsillitis and from four of the control group. These findings suggest a possible pathogenic role for the B melaninogenicus group in acute tonsillar infection in children.

Abscess↗