Microbiological Health Status and Antimicrobial Resistance Profiles in Free-Ranging and Rescued Psittacine Birds in Guatemala and Belize

To assess the microbiological status of two free-ranging populations of Scarlet macaw (Ara macao cyanoptera) in Guatemala (n=10) and Belize (n=14), and Yellow-headed amazon (Amazona oratrix belizensis) kept in a rescue centre in Belize (n=15), blood samples (n=39), faeces (n=16), cloacal (n=34) and choanal swabs (n=6) were collected for molecular, bacteriological and mycological investigations. On blood samples, PCRs for APV, PBFD, PDV and Chlamydia psittaci were carried out. Total bacterial and mycotic counts (UFC/swab/g) were recorded. To define the antibiotic resistance profiles, 11 antimicrobial and 2 antifungal categories were tested: Aminoglycosides, Penicillins, Penicillins+β-lactamase inhibitors, Cephalosporins, Quinolones, Carbapenems, Glycopeptides, Macrolides, Tetracyclines, Folate pathway inhibitors, Phosphonic acids, Polyenes, Azoles, following Kirby-Bauer and MIC methods (Oxacillin, Amoxicillin/Clavulanic acid, Vancomycin, Teicoplanin) according to the EUCAST guidelines. Data were analyzed using Chi Squared and Student t-test (STATA 13.0). All samples were negative to PCRs. Gram positive (63.1%, 8190±3495 UFC) and Gram negative bacteria (30.5%, P=0.003; 7600±4596, n=233) were cultured for a total of 218 isolates. Candida spp. and Rhodotorula spp. (4.3%, 2228±1483 UFC; n=13), Aspergillus spp. and Penicillum spp. (0.4%, 25±21 UFC; n=2) represented the fungal flora. Staphylococcus spp. (18.9%), Bacillus spp. (14.2%), Streptococcus spp. (12.9%), E. coli (6.4%), Burkolderia cepacia complex (6.0%), were the bacteria more representative. Samples resulted negative for Salmonella spp., Mycoplasma spp., and Clostridium spp. No significant difference was observed between captive and free-ranging birds, both for Gram +ve (63.2% vs 62.9%) and -ve (29.6% vs 31.5%). In free-ranging birds the mean total bacterial and fungal counts (7458±3175.5 and 1274±878.4 CFU) were lower compared to in captivity birds (8382±3175.5 and 2315.5±1636.1 CFU), but the differences were not significant (P>0.05). High significant resistance was observed for Penicillins (86.7%), Macrolides (57.3%), Penicillins+β-lactamase inhibitors (43.5%). Oxacillin Resistant Staphylococci (16.1%) and Glycopeptide non-Susceptible Staphylococci (20.0%) were isolated only from in captivity psittacine birds (P=0.0001), while free-ranging birds showed a high, but not significant, resistance to Macrolides (62.9%), Tetracyclines (39.3%; P=0.40). All fungal strains from in captivity birds resulted resistant to Polyenes. These are the first data on the microbiological health status and on bacterial and fungal antimicrobial susceptibility of healthy Psittacine birds in Guatemala and Belize. In rescued parrots, relevant resistance profiles were observed, hypothesizing the role of captivity in the transmission of resistant strains, mainly Staphylococci.