Prevalence and characterization of Salmonella among humans in Ghana.

BACKGROUND: Non-typhoidal Salmonella (NTS) is a public health problem worldwide and particularly in Africa with high disease burden. This study characterized Salmonella isolates from humans in Ghana to determine serovar distribution, phage types, and antimicrobial resistance. Further, the clonal relatedness among isolates was determined. METHODS: One hundred and thirty-seven Salmonella isolates (111 clinical and 26 public toilet) were characterized using standard serotyping, phage typing, and antimicrobial susceptibility testing methods. The molecular epidemiology of common serovars (Salmonella Typhimurium and Salmonella Enteritidis) was established by pulsed field gel electrophoresis (PFGE). RESULTS: Twenty-two serovars were identified with S. Enteritidis, S. Typhimurium, and Salmonella Derby as the most dominant. One hundred and twelve isolates showed resistance to more than one antimicrobial. Fifty-eight (n = 58/112; 54.5%) strains were multi-resistant with low resistance to cephalosporins ceftazidime (8.0%), cefotaxime (4.5%), and cefoxitin (2.7%) with synergy to clavulanic acid indicating possible ESBLs. Isolates showed high resistance to trimethoprim (66.1%), tetracycline (61.6%), ampicillin (57.1%), sulfamethoxazole (46.4%), chloramphenicol (33.9%), and ciprofloxacin (25.0%). The most common resistance pattern of multi-resistant serovars was to ampicillin, chloramphenicol, sulphonamide, and trimethoprim. S. Enteritidis (18/43) strains reacted with typing phages but did not conform to any phage type with PT14B and PT4 as predominant definitive phage types. Six S. Typhimurium strains reacted but did not conform to any recognized phage type while seven were non-typable. The predominant definitive phage types were DT1 and DT22. PFGE patterns of human S. Enteritidis were closely related to patterns of poultry isolates obtained in a previous study in Ghana. CONCLUSIONS: Cephalosporin resistance is uncommon among Salmonella from humans in Ghana. Poultry may be an important source of human salmonellosis. There is an urgent need for the implementation of routine surveillance of antimicrobial use and bacterial resistance among humans in Ghana.

Typing and Antibiogram of Vibrio cholerae Isolates from a Tertiary Care Hospital in Pune: A 3 Year Study.

A retrospective analysis was done over a period of 3 years (January 2010- December 2012) in a tertiary care hospital, Pune, to note the changes in the prevalence and distribution of biotypes, serotypes, antibiotic susceptibility pattern and phage types of Vibrio cholerae isolates from clinical samples so as to be vigilant and curtail major outbreak in future. Vibrio cholerae isolates were obtained from 4.4% of the 1126 fecal specimens processed from cases of acute watery diarrhea. Majority of the isolates were identified as V. cholerae O1 biotype El Tor serotype Ogawa (98%); Phage 27 was the predominant type (77.5%). Majority of the cases were encountered during the months June-August (68%). Antibiogram over a period of 3 years showed that isolates were consistently resistant to Ampicillin (90%) and Furazolidone (88%). Low level of resistance was seen with Norfloxacin (8%), Gentamicin (8%) and Tetracycline (6%). All isolates were susceptible to Chloramphenicol.

Bacteriophage types of methicillin-resistant Staphylococcus aureus in a tertiary care hospital.

BACKGROUND: Phage typing had been utilised extensively to characterise methicillin-resistant Staphylococcus aureus (MRSA) outbreak strains in the past. It is an invaluable tool even today to monitor emergence and dissemination of MRSA strains. AIMS: The aim of this study was to determine the prevalent phage types of MRSA in south India and the association between phage types, antibiotic resistance pattern and risk factors. METHOD: A total of 48 non-duplicate MRSA strains recovered from various clinical samples during January to December, 2010 were tested against a panel of anti-staphylococcal antibiotics. Phage typing was carried out at the National Staphylococcal Phage Typing Centre, New Delhi. Out of 48, 32 hospitalised patients were followed up for risk factors and response to empirical and post sensitivity antibiotic therapy. The risk factors were compared with a control group of 30 patients with methicillin sensitive Staphylococcus aureus (MSSA) infection. RESULTS: Amongst the five prevalent phage types, 42E was most common (52%), followed by a non-typable variant (22.9%), 42E/47/54/75 (16.6%), 42E/47 (6.2%) and 47 (2%). Phage type 42E was the predominant strain in all wards and OPDs except in the ICU where 42E/47/54/75 was most common. Although not statistically significant, strain 42E/47/54/75 (n=8) showed higher resistance to all drugs, except ciprofloxacin and amikacin, and were mostly D-test positive (87.5%) compared to the 42E strain (32%). Duration of hospital stay, intravenous catheterisation and breach in skin were the most significant risk factors for MRSA infection. CONCLUSION: We found MRSA strain diversity in hospital wards with differences in their antibiotic susceptibility pattern. The findings may impact infection control and antibiotic policy significantly.

Evolución de los serotipos, fagotipos y resistencia a antimicrobianos de Salmonella sp en el departamento de salud 02 de la provincia de Castellón, España (2000-2006) / Evolution of serotypes, phagotypes and antibiotic resistance of Salmonella spp in the 02 health district of Castellón, Spain (2000-2006)

Retrospective study of serotypes, phage types and antibiotic resistance of Salmonella spp isolates in the 02 Health District of Castellón, Spain (2000-2006). Strains were serotyped using commercial sera, and they were tested for antimicrobial susceptibility with automated systems. Serotyping confirmation and phage typing were performed by the National Reference Laboratory. A total of 1505 strains were isolated, with 49 different serotypes, being the most frequent Enteritidis. The most common serotype/phage type combination was S. Enteritidis phagetype 1. Of the isolates 81.6 percent were susceptible to amoxicillin/clavulanic acid; 65.2 percent to ampicilin; 99.9 percent to ciprofloxa-cin; 93.4 percent to trimethoprim-sulphametoxazole; and 99.8 percent to cefotaxime. Molecular methods could be useful to complete epidemiologic studies since 25 percent of our isolates showed the same serotype/phage type combination. In our health district antimicrobial resistance in Salmonella is not an important problem.

Salmonella Hadar phage types isolated from different sources of foodchain in Brazil

The gastroenteritis incidence caused by Salmonella Hadar has increased over the last decades worldwide. The uncontrolled use of antimicrobials for treating human patients and veterinary field contributes to increase the multidrug resistance of this serovar. In the present investigation, a total of 179 S. Hadar isolates from different sources of foodchain in Brazil were phage typed and analyzed for their antimicrobial resistance profile. The main S. Hadar phage types isolated were PT 38, PT 39, PT 40, PT 11, PT 34, PT 1 and PT 22. Others phage types as PT 13, PT 19, PT 21, PT 23, PT 31, PT 33 and PT 37 were obtained in low percentages. A total of 35,7 percent S. Hadar strains were resistant to two or more antimicrobials drugs. Furthermore, no resistance to third generation cephalosporin or ciprofloxacin was identified in these strains. Those results appoint to S. Hadar phage types circulating among animals, food and humans, as well as the increasing of multidrug resistance. The surveillance and monitoring of S. Hadar strains based on phage typing and antimicrobial resistance profile are useful for detecting outbreaks, identifying sources of infection and implementing prevention and control measures of salmonellosis.

A incidência de gastrenterite causada por Salmonella Hadar tem aumentado ao longo dos anos em todo o mundo. O uso indiscriminado de antimicrobianos na clínica humana e veterinária tem contribuído para o aumento da multiresistência deste sorovar. No presente estudo, 179 cepas de S. Hadar isoladas de diferentes fontes da cadeia alimentar no Brasil foram fagotipadas e analisadas quanto ao perfil de resistência antimicrobiana. Os principais fagotipos de S. Hadar isolados foram PT 38, PT 39, PT 40, PT 11, PT 34, PT 1 e PT 22. Outros fagotipos como PT 13, PT 19, PT 21, PT 23, PT 31, PT 33 e PT 37 foram obtidos em menores percentagens. Um total de 35,7 por cento das cepas avaliadas foi resistente a dois ou mais antimicrobianos. Por outro lado, não foi observada resistência a cefalosporinas de terceira geração ou ciprofloxacina. Esses resultados apontam para a circulação de fagotipos de S. Hadar entre animais, alimentos e seres humanos, bem como o aumento da multiresistência antimicrobiana. O monitoramento de cepas de S. Hadar baseado na fagotipagem e no padrão de resistência aos antimicrobianos são ferramentas úteis na detecção de surtos, identificação das fontes de infecção, além de auxiliar na implantação de programas de controle e prevenção de salmoneloses.