Molecular, antibiogram and serological typing of Staphylococcus aureus isolates recovered from Al-Makased Hospital in East Jerusalem.

Staphylococcus aureus is a major cause of nosocomial infections and a risk in patients who have either undergone surgery or are on haemodialysis. The S. aureus infections in patients admitted to the clinical departments of Al-Makased Charitable Hospital in Jerusalem during a period of one year were investigated. Isolates included were from blood, surgical wounds, or other nonsuperficial sites. Of 63 isolates available for analysis, 46 (73.0%) expressed type 8 capsular polysaccharide; 13 (20.7%), type 5 capsular polysaccharide; only 4 isolates (6.3%) did not express type 5 or type 8 antibodies. The strains fitted in 7 different antibiogram types, with the type showing resistance only to penicillin and ampicillin prevalent in 34 out of 63 isolates (54.0%). Of the 12 methicillin-resistant S. aureus (MRSA) isolates (19.1%), 8(66.7%) possessed the type 8 capsule and 4(33.7%) the type 5 capsule. Pulsed-field gel electrophoresis of all isolates with the restriction-endonuclease enzymes Sma I revealed 34 patterns demonstrating that no single methicillin-sensitive S. aureus strain was endemic in the hospital. However, all MRSA isolates with a type 8 capsule showed identical PFGE patterns using the 2 restriction-endonuclease enzymes Sma I and SST II. Moreover, type 5 isolates showed identical patterns (one isolate differed from the rest with one band only). These data suggest and confirm the clonality of type 5 and type 8 MRSA isolates. Analysing the results of the capsular and antibiogram typing schemes in conjunction proved useful and suggested that such an analysis can be employed as a helpful epidemiological tool in hospitals with limited resources.

Phenotypic and genotypic characterization of nosocomial Staphylococcus aureus isolates from trauma patients.

Staphylococcus aureus is a major cause of nosocomial infections. During the period from March 1992 to March 1994, the patients admitted to the intensive care unit of the University of Maryland Shock Trauma Center were monitored for the development of S. aureus infections. Among the 776 patients eligible for the study, 60 (7.7%) patients developed 65 incidents of nosocomial S. aureus infections. Of the clinical isolates, 43.1% possessed a polysaccharide type 5 capsule, 44.6% possessed a type 8 capsule, and the remaining 12.3% had capsules that were not typed by the type 5 or type 8 antibodies. Six antibiogram types were noted among the infection-related isolates, with the majority of the types being resistant only to penicillin and ampicillin. It was noted that the majority of cases of pneumonia were caused by relatively susceptible strains, while resistant strains were isolated from patients with bacteremia and other infections. Only 16 (6.3%) of the isolates were found to be methicillin-resistant S. aureus (MRSA). DNA fingerprinting by pulsed-field gel electrophoresis showed 36 different patterns, with characteristic patterns being found for MRSA strains and the strains with different capsular types. Clonal relationships were established, and the origins of the infection-related isolates in each patient were determined. We conclude that (i) nosocomial infection-related isolates from the shock trauma patients did not belong to a single clone, although the predominance of a methicillin-resistant genotype was noted, (ii) most infection-related S. aureus isolates were relatively susceptible to antibiotics, but a MRSA strain was endemic, and (iii) for practical purposes, the combination of the results of capsular and antibiogram typing can be used as a useful epidemiological marker.

National cross-sectional study of mastitis in dairy cattle in Jordan.

Between July 1991 and August 1992, 63 Jordanian dairy farms selected by stratified random sample were visited to identify the major causes and prevalence of intramammary infections in dairy cows. Of 773 cows examined 60% of all sampled quarters had > 283,000 cells/ml. The mean value of somatic cell count (SCC) was positively associated with age in lactations and negatively with herd size. Cows milked by bucket milking machines or in fully automatic parlours had a lower mean SCC than those milked by hand. Many management faults pertaining to milking procedure and maintenance of milking machines were noted. The most common isolate from clinical cases was Staphylococcus aureus (37.5%). Estimates of prevalence of bacterial pathogens in intramammary infections were: coagulase negative staphylococci (16.04%), S. aureus (9.41%), Klebsiella spp. (6.17%), Corynebacterium bovis (5.35%) and Brucella melitensis (4.52%). The results demonstrate the essential need for the development of a national mastitis control programme.

In vitro activities of antimicrobial agents against Proteus species from clinical specimens.

Two hundred clinical isolates of members of the genus Proteus were definitively identified and their antimicrobial susceptibilities to 12 antimicrobials tested, 176 isolates (88%) being identified as Proteus mirabilis, 12 strains (6%) as Proteus vulgaris and 12 strains (6%) as Proteus penneri. Most strains were isolated from pus (62.5%) and urine (34%), but in general there were no significant differences in the rates of isolation of any of the species by age or sex, although it was noted that P. vulgaris was only isolated from patients belonging to the older age group (> 5 years). The Proteus spp. were notably susceptible to nalidixic acid, ceftazidime and the aminoglycosides tested, and resistant to polymyxin B and colistin. The inclination of certain Proteus species to be susceptible or resistant to certain antimicrobials was noted, but strain differences also existed. The results of the study confirm the importance of performing antimicrobials susceptibility testing of each Proteus isolate to avoid potentially misleading therapy. The noted discrepancy in the result of the susceptibility of P. penneri to chloramphenicol as tested by different standard methods merits further investigation.

Microbial contamination and preservative efficacy of topical creams.

Nineteen different brands of topical creams were tested in duplicate for microbial growth. The efficacy of their preservation was assessed, when possible, by standard pharmacopoeial procedures. Microbial growth was demonstrated in cultures from all specimens. However, high counts (> 10(4) c.f.u./g) were obtained from eight specimens from six different brands. The microbes were found to belong to different species of bacteria and fungi including Pseudomonas aeruginosa. Two samples of each of the seven, easily emulsifiable creams, were challenged with standard strains of Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Candida albicans to assess the efficacy of the preservatives used in their preparations. With the exception of a single brand, all creams tested were ineffectively preserved. This study highlights the dangers of marketing domestically prepared topical creams and more effective monitoring of the components for all topical creams is recommended. The inclusion of a proper preservative system in these formulas is essential.

A study of the bacterial and parasitic causes of acute diarrhoea in northern Jordan.

The prevalence of bacterial and parasitic diarrhoeagenic agents in 200 patients suffering from acute diarrhoea and reporting to hospitals and health centres in northern Jordan, and in controls was determined. One or more bacterial or parasitic enteropathogens was isolated from 79 patients (39.5%). Prevalence rates for these pathogens was as follows: Enterotoxigenic Escherichia coli, 9%; enteropathogenic E. coli, 9%; Salmonella spp. 7%; Campylobacter spp, 5.5%; Yersinia enterocolitica, 4.5%; Shigella spp, 4%; Aeromonas spp, 3.5%; enterotoxigenic Clostridium perfringens, 2%; Vibrio spp, 2%; and Plesiomonas shigelloides, 0.5%. Both Giardia lamblia and Entamoeba histolytica were detected in 2% of the stool samples examined. Although the determination of the aetiologic role of the identified enteropathogens was complicated by more than one factor, the data collected will serve as a baseline for future studies of the subject.

Nasal carriage of methicillin-resistant Staphylococcus aureus by hospital staff in north Jordan.

The nasal carriage of methicillin-resistant Staphylococcus aureus was detected in 550 hospital staff members of four hospitals in north Jordan. Of the 109 (19.8%) individuals tested who were nasal carriers of S. aureus, only 32 (5.8%) were found to be carriers of methicillin-resistant Staphylococcus aureus. The carriers were four doctors, 23 nurses, three laboratory technicians, one maid and an administrator. It was noted that 25 (78.1%) of these carriers were in constant contact with patients in operating theatres, surgical wards or intensive care units. It was not clear whether the carriers were short- or long-term carriers, or whether they were persistent sources of methicillin-resistant Staphylococcus aureus. Decontamination of these carriers was considered among other control measures to avoid the dangerous outcome of hospital outbreaks caused by this potential pathogen.

The role of day care givers in the identification and prevention of infections.

The prevalence of nasopharyngeal Streptococcus pyogenes in children attending day care centers in North Jordan was studied. Nasal and throat swabs, cultured for Streptococcus pyogenes were collected from 100 children enrolled in four day care centers serving middle to high socioeconomic status portions of the population in March 1989. The identity of the streptococcal isolates was confirmed by biochemical and serological methods. Throat infection manifestations of the past 3 days, as reported and observed by the care givers, were related to culture results. The study findings showed that the prevalence of nasopharyngeal Streptococcus pyogenes was high and ranged between 10 to 23.3%. It was also noted that the care givers were able to correctly identify children with suspected throat infection, in 11 to 25% of the children who grew Streptococcus pyogenes on cultures, by mere observation of the symptoms. Due to the high prevalence of nasopharyngeal Streptococcus pyogenes in these settings, measures to control and prevent the spread of Streptococcus pyogenes must be employed. This study suggests that care givers may play an important role in achieving such a goal if they are offered proper health education programs and instructions on child hygiene.

A study of group B streptococcal carrier state during late pregnancy.

The carriage of Group B Streptococcus was investigated in 500 females in the third trimester of their pregnancy by culturing vaginal and rectal swabs and urine collected from each patient. A high rate of colonization was noted since 152 cases (30.4%) were found to harbor the organism, and 219 specimens (48%) from a total of 456 collected from these 152 cases were positive for Streptococcus agalactiae. Of the 219 positive specimens, 94 (42.9%) were vaginal swabs, 90 (41.1%) were rectal swabs and the remaining 35 (16%) were urine specimens. It is recommended that vaginal and rectal swab culture be used to detect carriers of group B streptococci, since using such a combination in this study revealed 91.4% of all positive cases.

The effect of the pH of various dairy products on the survival and growth of Brucella melitensis.

In this study we report the effect of the pH of various dairy products on the survival and growth of Brucella melitensis. The growth patterns of B. melitensis in broth media at different pHs (ranging between 3 and 9) were studied for up to four weeks, to standardize the growth of the organism at each pH. These growth patterns were compared with those of the same organism growing in different dairy products [milk, soft cheese, yoghurt, and buttermilk (shaneena)] under the same growth conditions. This showed that B. melitensis could survive for more than four weeks in broth at a pH of greater than or equal to 5.5, was inhibited in less than three weeks at pH 5 and in one day at pH 4, but could not survive in a pH of less than 4. In dairy products there was a marked drop in the total viable count, and the organism could not be detected after short periods of time. After 72 hours B. melitensis could be detected only in soft cheese, but it was not detectable in any of the dairy products tested after 96 hours. Thus, this study has shown that the survival of B. melitensis in the different dairy products was inversely proportional to the pH of the product.

Microbial contamination and preservation efficacy of cough preparations.

Cough syrups, manufactured by four different Jordanian pharmaceutical companies, were examined for microbial contents and efficacy of preservation from fungal and bacterial contamination. Five per cent of the tested samples were found to be contaminated by Candida albicans and 30% of the products examined did not comply with the pharmacopoeial requirements for optimal preservation from fungal contamination. All the products tested were free from bacteria and were efficiently preserved against accidental bacterial contamination.

Comparison of biochemical, morphologic, and chemical characteristics of Centers for Disease Control fermentative coryneform groups 1, 2, and A-4.

A total of 24 strains of fermentative coryneform like bacteria isolated from clinical specimens form two distinct groups which have been designated Centers for Disease Control (CDC) fermentative coryneform groups 1 (13 strains) and 2 (11 strains). The phenotypic characteristics of group 1 were similar to those of a previously described CDC group designated A-4, with the major differentiating characteristic being the inability to hydrolyze esculin. Major differences in cellular fatty acid composition between CDC groups 1 and A-4 were also observed. The branched-chain fatty acids 14-methylhexadecanoate and 12-methyltetradecanoate, which account for more than 80% of the total acids of group A-4, were not detected in cells of group 1 strains. Groups 1 and 2, which have similar cellular fatty acid compositions, can be differentiated on the basis of fermentation of xylose, mannitol, lactose, sucrose, and melibiose by group 1 but not by group 2. The sources of isolation of the strains of both groups varied. Only group 1 strains were associated with eye infections.