Recovery and screening for antibiotic susceptibility of potential bacterial pathogens from the oral cavity of shark species involved in attacks on humans in Recife, Brazil

Abstract

The number of incidents involving sharks and humans at beaches in Recife, on the north-eastern Brazilian coast, is among the highest worldwide. In addition, wound infections in survivors are common; but the nature and risk of the aetiological agents is unknown. In the present study, 81 potential bacterial pathogens were identified in the oral cavity of sharks involved in attacks in Recife, and were subjected to antibiotic susceptibility tests using the standardized disc-diffusion method. The majority were enterobacteria such as Enterobacter spp., Citrobacter spp., Proteus spp., Providencia alcalifaciens, Escherichia coli, Moellerella wisconcensis and Leclercia adecarboxylata. Other Gram-negative bacteria included Vibrio spp., Burkholderia cepacia, Acinetobacter spp. and Pseudomonas spp. In addition, coagulase-positive and coagulasenegative Staphylococcus spp., Enterococcus spp. and Micrococcus spp. were identified, besides Streptococcus spp. from the viridans group. Resistance was especially found in the Proteus mirabilis and Citrobacter freundii, and ranged from 4 to 6 antibiotics out of the 13 tested. Gentamicin and vancomycin were the most effective against Gram-positive cocci strains, whereas levofloxacin was fully inhibitory against Gram-positive and Gram-negative bacteria. These data are discussed in light of a retrospective evaluation of the medical records of three shark victims treated at Restauraç ã o Hospital in Recife.

Is Leclercia adecarboxylata a New and Unfamiliar Marine Pathogen?

“…Recently, cellulitis caused by L. adecarboxylata was reported in a man 1 week after cleaning up floodwater in his basement after Hurricane Irene (17). Another clue linking L. adecarboxylata to marine or water environments is the isolation of this organism in the oral cavity of sharks involved in human attacks in Brazil (18).…”

Antibiotic Susceptibilities of Bacteria Isolated within the Oral Flora of Florida Blacktip Sharks: Guidance for Empiric Antibiotic Therapy

“…Additionally, antibiotic resistance, bacterial composition (i.e. gram-positive, gram-negative) and mean number of bacteria were extracted from the study by Interaminense et al [15] and compared to data from this study using a two-sample t-test. A p-value of less than 0.05 was considered significant.…”

“…in marine animals, including sharks [12]–[17]. Of great interest is the degree of antibiotic resistance observed in these studies, which may be related to the pumping of sewage into the waters [12]–[15], [17]–[20]. In Brazil, oral samples collected post-mortem from bull sharks ( C. leucas ) and tiger sharks ( Galeocerdo cuvier ) revealed a high-level of antimicrobial resistance among Enterobacteriaceae , including 20% of Proteus mirabilis resistant to imipenem, a broad-spectrum antibiotic [15].…”

“…Of great interest is the degree of antibiotic resistance observed in these studies, which may be related to the pumping of sewage into the waters [12]–[15], [17]–[20]. In Brazil, oral samples collected post-mortem from bull sharks ( C. leucas ) and tiger sharks ( Galeocerdo cuvier ) revealed a high-level of antimicrobial resistance among Enterobacteriaceae , including 20% of Proteus mirabilis resistant to imipenem, a broad-spectrum antibiotic [15]. Additionally, samples from the cloaca-anus of nurse sharks ( Ginglymostoma cirratum ), bull sharks, blacktip sharks and lemon sharks ( Negaprion brevirostris ) also demonstrated resistance to several tested antibiotics, including approximately 20–35% resistance amongst amikacin, ceftazidime and piperacillin [12].…”

Leclercia adecarboxylata, a rare cause of soft tissue infections in immunocompromised patients, case report and review of the literatura

“…L. adecarboxylata is thought to be distributed widely in nature, present in food, water sources, egg shells, milk, industrial fat and oil reservoirs and as a commensal of the gut flora of some animals 1,3,[7][8][9] ; it has also been recovered, uncommonly, from human samples like blood, bone 10 , cardiac valve, wounds, bronchial wash 11 , peritoneal fluid, urine, gall bladder, synovial fluid, abscesses and epididymo-orchitis, from immunocompromised and immunocompetent patients, being the former the most relevant and frequent scenario, as the case of our patient, and the later generally but not always associated to polymicrobial infections, suggesting the dependence of this bacteria on other microorganisms to infect immunocompetent hosts 1,7 .…”