Bacterial Prevalence and Resistance to Antimicrobial Agents in Southwest , Saudi Arabia

One hundred and eighty eight organisms were isolated from clinical specimens (71 isolates from urine, throat swabs (40), stool (39) pus (17), blood (14), wound swabs (7) collected from laboratories of hospitals and polyclinics distributed in Najran Area, Saudi Arabia, between February 2010 to November 2011. Bacteria were identified by Gram staining and biochemical tests, and antibiotic sensitivities tested by the disc diffusion method at microbiology laboratory, Najran University. The most prevalent bacteria isolated were E. coli (35.63%) followed by Klebsiella pneumoniae (18.08%), Staph. aureus (14.89%), Salmonella spp. (13.29%), Pseudomonas aeruginosa (6.91%), Streptococcus pneumoniae (5.31%), Shigella spp (3.19%), Enterococcus faecalis (1.59%) and Proteus mirabilis (1.06%). The multi-drug resistance rates (MDR) among common isolates were Pseudomonas aeruginosa (38.46%) followed by Klebsiella pneumoniae (32.35%), Staph. Aureus (32.14%) and E. coli (31.34%). The overall multi-drug resistance rate among isolates was high (28.72%).


INTRODUCTION
Antibiotic resistance has become a major clinical and public health problem.We are currently faced with (multi) resistant bacteria that are difficult and sometimes impossible to treat, Levy, S.B. (2002).The tremendous therapeutic advantage afforded by antibiotics is being threatened by the emergence of increasingly resistant strains of microbes, Livermore, D.M. (2005).The problem has recently been worsened by the steady increase in multi-resistant strains and by the restriction of antibiotic discovery and development programs, Levy S. B (2002).The widespread use of antibiotics both inside and outside of medicine is playing a significant role in the emergence of resistant bacteria, Bacon, D.J. et al. (2000).Antimicrobials have transformed our ability to treat many infectious diseases that were killers only a few decades ago.The increasing use of antimicrobials in humans, animals, and agriculture has resulted in many pathogens developing resistance to these powerful drugs, Sakharkar, MK. et al. (2009) et al. (2004).In recent times new mechanisms of resistance have resulted in the simultaneous development of resistance to several antibiotic classes creating very dangerous multidrugresistant (MDR) bacterial strains, some also known as "superbugs" Nienke van de Sande-Bruinsma, et al. (2008).The need for new antimicrobial agents is greater than ever because of the emergence of multidrug resistance in common pathogens, the rapid emergence of new infections, and the potential for use of multidrug-resistant agents in bioweapons, Kent Peters, N. et al. (2008).Controlling the spread of resistance requires the collaboration of several participants such as Veterinary, Medical, and Public Health Communities, Angulo, F.J. et al. (2004).Multidrug resistant organisms (MDROs) are resistant to one or more classes of antimicrobial agents and the knowledge of susceptibility pattern is helpful in selecting the empirical therapy and improving the likelihood of a satisfactory outcome for patient, Sameera M. et al. (2010).The objective of this study was to determine bacterial pathogens prevalence and to assess the multi-drug resistant (MDR) strains to different antibiotics in southwest, Saudi Arabia.

MATERIALS AND METHODS Sample Collection
Mid-stream urine, stool, pus, wound swabs, throat swabs and blood specimens were collected aseptically for bacteriological examination from laboratories of hospitals and polyclinics distributed in Najran Area between February 2010 to November 2011.Handling, transporting and storing of collected samples were made at refrigeration temperature.

Isolation and Identification
Urine, pus, wound swabs, throat swabs and blood specimens were cultured onto blood agar and MacConkey agar media.Stool specimens were inoculated onto Salmonell-Shigella agar (including a subculture of Selenite-F broth), Xylose Lysine deoxycholate and Mac Conkey agar media then incubated at 37ºC for 18-24 hours.Bacteriological smears were prepared from the growing colonies then stained with gram stain for morphological identification.All the bacterial isolates were preserved on nutrient agar slants at 4ºC and subcultured periodically.The obtained pure cultures were identified biochemically, Holt, J. G. et al. (1994) and Pelczar, M. J. et al. (1999).
(25 ug).The proportion of susceptible organisms was calculated as the sum of susceptible isolates relative to the total number of organisms tested.The organism considered as multidrug resistant if it is resistant to three or more antimicrobials.

Table 1 :
Bacterial species isolated from urine specimens:

Table 6 :
Bacterial species isolated from wound swabs.

Table 7 :
Overall Bacterial prevalence and susceptibility pattern.

Bacterial Prevalence and Resistance to Antimicrobial Agents in Southwest, Saudi Arabia 109
Table 7).These results approximately agree with those recorded by, Narten, Maike et al., 2012 and Sameera M. et al., 2010, recorded significant resistance of cefotaxime to E coli (24%-54%).Mohanty et al., 2004, found that resistance in S. aureus was 38.56%, high level aminoglycoside resistance was observed in 53.3% of enterococci and 66.75% of the gram negative bacilli in North India.The overall multi-drug resistance rate was 28.72%.Higher number of resistant bacteria seen in Saudi Arabia might be due to greater antibiotic consumption, Alireza Ekrami and Enayat Kalantar (2007).Asghar and Faidih, 2010, performed a study in Makkah.They reported much higher resistance rate among gram negative bacteria in comparison with other countries in the world which necessitates implementation of monitoring program.Therefore developing nationwide antibiotic policy and guidelines is essential to limit multidrug resistance and to maintain low level of resistance to newer antibiotics in Saudi Arabia.European