β-Lactamase Production by Oral Anaerobic Gram-Negative Species in Infants in Relation to Previous Antimicrobial Therapy

Abstract

The frequency of β-lactamase production in gram-negative bacteria has increased considerably during recent years. In this study, β-lactamase production by oral anaerobic gram-negative rods isolated from saliva was longitudinally examined for 44 Caucasian infants at the ages of 2, 6, and 12 months in relation to their documented exposure to antibiotics. Isolates showing decreased susceptibility to penicillin G (1 μg/ml) were examined for β-lactamase production by using a chromogenic cephalosporin disk test. β-Lactamase-positive, gram-negative anaerobic species were found in 11, 55, and 89% of each age group, respectively. β-Lactamase production was most frequent among organisms of the Prevotella melaninogenica group. At 12 months, 73% of the infants harbored β-lactamase-producing members of the P. melaninogenica group, 55% had nonpigmentedPrevotella species, 25% had Porphyromonas catoniae, 23% had Fusobacterium nucleatum, and 5% had Capnocytophaga species. Several β-lactamase-producing species could be simultaneously found in the infants’ mouths. The presence of β-lactamase-producing species was significantly associated with the infants’ exposure to antibiotics through antimicrobial treatments given to the infants and/or their mothers.

Impact of antimicrobial exposure and β-lactamase-producing bacteria on salivary β-lactamase activity in infancy

“…and F. nucleatum [1,7]), and 21 aerobic isolates (Haemophilus parainfluenzae, Moraxella catarrhalis and staphylococci [12]) and the relationship between S␤A and data on infants' exposure to antimicrobial agents during the first year of life [7] was examined. Chi-square tests were used to analyse the associations between the presence of ␤-lactamase-producing bacteria and S␤A, and between antimicrobial exposure and S␤A.…”

“…According to our working hypothesis, harbouring oral ␤-lactamase-producing species is reflected in ␤-lactamase activity in saliva. Since infants' exposure to antimicrobial agents increases the prevalence of ␤-lactamaseproducing species [7], exposure to antimicrobial agents will most likely increase the salivary ␤-lactamase activity as well. In the present study, our aims were, firstly, to examine the frequency of salivary ␤-lactamase activity (S␤A), secondly, to compare this activity with the presence of ␤-lactamaseproducing (␤+) bacteria in saliva, and finally, to estimate the impact of exposure of antimicrobial agents, on the emergence of S␤A in a group of healthy infants during the first year of life.…”

“…Production of ␤-lactamases by many oral anaerobic species is common in childhood [4][5][6][7][8]. If the enzyme is secreted extracellularly [9], it will appear in surrounding tissues and secretions.…”

Bacterial resistance and the dental professionals’ role to halt the problem

“…[33][34][35] In addition, b-lactamase-producing Bacillus and Pseudomonas species were isolated from subgingival plaque in patients with chronic periodontitis. 36 The Prevotella species has been reported to be the most frequent b-lactamase-producing species found in periodontal pockets and saliva, [36][37][38] and it is frequently detected in infants and healthy young children. 38,39 Isolates of Fusobacterium nucleatum were shown to produce significant amounts of b-lactamase in patients suffering from tonsillitis.…”

“…36 The Prevotella species has been reported to be the most frequent b-lactamase-producing species found in periodontal pockets and saliva, [36][37][38] and it is frequently detected in infants and healthy young children. 38,39 Isolates of Fusobacterium nucleatum were shown to produce significant amounts of b-lactamase in patients suffering from tonsillitis. 40 In addition, Kö nö nen et al demonstrated that penicillin resistance caused by b-lactamase production by oral strains of F. nucleatum frequently occurs in childhood.…”