Antibiotic-resistance patterns of bacterical pathogens isolated from ornamental fish in Trinidad and Tobago

Ornamental fish farming forms an important part of the local aquaculture industry in Trinidad and Tobago, and the number of farms has been increasing annually. This study was designed to ascertain the prevalence of bacterial pathogens from fish and pond water, and determine the resistance of the bacteria to commonly used antimicrobial agents. A total of 1204 bacterial isolates were recovered: from 575 fish slurry and 111 water samples from 17 aquaculture farms. Isolates from fish were identified as belonging to 19, and those from water samples were grouped in 18 genera. The predominant genera isolated were (in descending order) Aeromonas spp., Pseudomonas spp., Plesiomonas spp., Chromobacterium spp., Enterobacter spp. and Serratia spp. Screening against 8 antimicrobial agents showed that 95.1 percent (774 of 814) of isolates from fish slurry, and 98.4 percent (254 to 258) of isolates from pond water were resistant to one or more antimicrobial agents ( P> 0.05, X2). The highest resistance (55-94 percent) were to ampicillin, oxytetracycline and erythromycin, but relatively lower resistance (4-14 percent) occurred to gentamycin and norfloxacin (P< 0.05; X2). It was concluded that the high prevalence of bacterial pathogens in ornamental fish coupled with their high levels of resistance to antimicrobial agents may pose therapeutic problems as well as health risks to farmers, workers and fish hobbyists

Frequency and antimicrobial resistance of enteric bacteria with spoilage potential isolated from table eggs

The prevalence of potential spoilage microorganisms on the shells and in the egg contents of table eggs sold in Trinidad was determined. Table eggs samples were obtained from 23 poultry layer farms, 14 shopping malls and 102 supermarkets across the country. Each farm was visited twice approximately one month apart and 25 pooled eggs constituted a composite sample. Shopping malls were each visited twice usually one month apart while supermarkets were each visited once over a 4-month period. For both mall and supermarkets, six pooled eggs constituted a composite sample. Swabs of egg shells and pooled yolk and albumen (egg content) were tested for selected bacteria using standard methods. The resistance of bacteria to seven antimicrobial agents was detected using the disc diffusion method. Of a total of 184 composite eggs (shells, yolk/albumen or both) sampled, 71 (38.6 per cent) samples were positive for enteric microbes, other than E. coli, Salmonella, Campylobacter spp. and Listeria spp. Enterobacter spp. and Klebsiella spp. were isolated from 15 (8.2 per cent) and 14 (7.6 per cent), respectively, of pooled egg shells alone and from 6 (3.3 per cent) and 3 (1.6 per cent), respectively, of egg content samples alone. Prevalence of enteric bacteria in egg contents was generally higher than found on egg shells with faeces/blood or cracks compared with those without, but the differences were not significant (P > 0.05; X2). The microbial load of egg content was not significantly affected by type of housing of laying birds, source of feeds, use of medicated feeds and temperatures at which eggs were kept at sale outlets. Of a total of 131 bacterial isolates tested, 125 (95.4 per cent) exhibited resistance to one or more antimicrobial agents and resistance was high to streptomycin (90.1 per cent), tetracycline (51.9 per cent) and kanamycin (30.5 per cent).

High frequency of multidrug-resistant Mycobacterium tuberculosis isolates in Georgetown, Guyana

Emergence of multi-drug resistance (MDR) Mycobacterium tuberculosis isolates constitutes a threat to public health worldwide. This study aimed at acquiring first epidemiological data for Guyana. Thirty-six M. tuberculosis isolates from patients of the Georgetown Chest Clinic were subjected to susceptibility testing on solid agar and in broth media. Resistance to at least one first-line drug was observed in 8 (22.2 percent, 95 percent confidence interval 8.3 -36.1 percent) and simultaneous resistance to rifampicin and isoniazid (MDR) in 4 (11.1 percent, 95 percent confidence interval 0.6-21.6 percent) of the 36 isolates. The risk of infection with resistant isolates was significantly related to earlier antituberculosis therapy (P=0.040). These data indicate a high proportion of resistant M.tuberculosis isolates in Guyana and call for the implementation of control strategies based on an improved laboratory diagnosis of TB(AU)

Third generation cephalosporin use in a tertiary hospital in Port of Spain, Trinidad: need for an antibiotic policy

BACKGROUND: Tertiary care hospitals are a potential source for development and spread of bacterial resistance being in the loop to receive outpatients and referrals from community nursing homes and hospitals. The liberal use of third-generation cephalosporins (3GCs) in these hospitals has been associated with the emergence of extended-spectrum beta- lactamases (ESBLs) presenting concerns for bacterial resistance in therapeutics. We studied the 3GC utilization in a tertiary care teaching hospital, in warded patients (medical, surgical, gynaecology, orthopedic) prescribed these drugs. METHODS: Clinical data of patients (>or= 13 years) admitted to the General Hospital, Port of Spain (POSGH) from January to June 2000, and who had received 3GCs based on the Pharmacy records were studied. The Sanford Antibiotic Guide 2000, was used to determine appropriateness of therapy. The agency which procures drugs for the Ministry of Health supplied the cost of drugs. RESULTS: The prevalence rate of use of 3GCs was 9.5 per 1000 admissions and was higher in surgical and gynecological admissions (21/1000) compared with medical and orthopedic (8 /1000) services (p < 0.05). Ceftriaxone was the most frequently used 3GC. Sixty-nine (36%) patients without clinical evidence of infection received 3Gcs and prescribing was based on therapeutic recommendations in 4% of patients. At least 62% of all prescriptions were inappropriate with significant associations for patients from gynaecology (p < 0.003), empirical prescribing (p < 0.48), patients with undetermined infection sites (p < 0.007), and for single drug use compared with multiple antibiotics (p < 0.001). Treatment was twice as costly when prescribing was inappropriate. CONCLUSIONS: There is extensive inappropriate 3GC utilization in tertiary care in Trinidad. We recommend hospital laboratories undertake continuous surveillance of antibiotic resistance patterns so that appropriate changes in prescribing guidelines can be developed and implemented. Though guidelines for rational antibiotic use were developed they have not been re-visited or encouraged, suggesting urgent antibiotic review of the hospital formulary and instituting an infection control team. Monitoring antibiotic use with microbiology laboratory support can promote rational drug utilization, cut costs, halt inappropriate 3GC prescribing, and delay the emergence of resistant organisms. An ongoing antibiotic peer audit is suggested.